Coffee: A Natural Processing Experiment Part 1- Processing Methods

Regular readers will be aware I do a little coffee roasting at home, the majority of which occurs with green coffee beans bought online. A couple of years ago I published a five-part series on the techniques involved with washed processing of coffee, taking a very small batch through the processing stages from cherry off the tree and into the cup.

Back in November last year I republished these in a single post, in the knowledge I would be running through a similar experiment using natural processing methods. Around the same time I also put together a short piece about the app Day One, and how I planned to use it to monitor my progress.

One of my main aims in writing here is to push myself along in learning a little more about the specific details of my interests — in this case, coffee processing. To that end, it will help to look at some background information before I get started.

Coffee processing — what are the options?

Although the following is not a detailed explanation of each, it should serve as a general indication of the differences between the various processing options available after coffee is harvested from the tree. The three more popular methods at the current time are natural (dry), washed (wet) and honey processing. I will also briefly describe the semi-washed or wet-hulled method, and a semi-dry method: pulped natural processing.

The information that follows is a put together from the following sources, all of which I’d recommend for more detailed information and accompanying images:

Cafe ImportsCoffee Processes

D.R. WakefieldThe difference between semi-washed and fully washed methods

Perfect Daily GrindIndonesian Wet Hulled Coffee: Your One-Stop Guide

Origin Coffee RoastersBlack. Red. White. A Guide to Costa Rica’s Honey Process

Cafe BrittHoney Processed Coffee: What makes it so special?

Seattle CoffeeworksWhat on Earth is Honey Process?

James HoffmannThe World Atlas of Coffee (Book)

The article on the Seattle Coffeeworks blog is particularly useful to view the “anatomy” of a coffee bean, and provides a little more detail in describing each of the layers, which might be helpful in gaining a better understanding of some of the terms described below.

For reference, the following schematic diagram names each layer in the entire coffee cherry:

  1. 2000px-Coffee_Bean_Structure.svgCentre cut
  2. Bean or seed (endosperm)
  3. Silver skin (epidermis)
  4. Parchment (hull, endocarp)
  5. Pectin layer (mucilage)
  6. Pulp or flesh (mesocarp)
  7. Outer skin (pericarp, exocarp)

 

Wet processing methods

Fully washed

Described in its simplest form, wet processed or washed coffee involves extracting and fermenting the bean from the flesh of the pulp, followed by drying, or more specifically:

  1. The external fruit pulp (exocarp and part of the mesocarp) is removed by mechanical de-pulping machines;
  2. The remaining mesocarp or “mucilage” is insoluble in water and clings to the parchment layer strongly, needing removal by fermentation and washing, or friction in mucilage removal machines;
  3. The beans may then be taken through a second washing to remove any remaining debris;
  4. Drying is then undertaken on patios or raised drying beds.

(Note: this method is what I have described in my five-part series of posts linked to above; the above stages are all completed by hand rather than machine when done on a small-scale)

Wet-hulled or semi-washed

Typically a method used in countries such as Indonesia, where humidity is high, and rainfall abundant. Wet-hulling (giling-basah) is a traditional processing method used in these countries, and was developed due to the particular climate and conditions:

  1. After harvesting, the pulp is removed, leaving the mucilage and parchment covering the bean;
  2. Beans are fermented in concrete tanks or plastic rice bags overnight (this process assist with breaking down the pectin in the mucilage for easier removal);
  3. The beans are then washed to remove the mucilage (or sold to a larger processing mill to continue the processing);
  4. After mucilage removal, remaining is the wet parchment, hence this coffee may also be called “wet parchment coffee”;
  5. Sun drying occurs for 2-3 days, reducing the moisture content to 20-24% (wet processed coffees are dried to a moisture content of 11-12%, rendering the parchment brittle for easier removal);
  6. The parchment is then removed using machinery specifically designed for wet parchment coffee (greater friction is required);
  7. Further drying occurs in the sun by day, with the coffee stored in bags overnight to continue the fermentation until the moisture content is reduced to the desired level.

An interesting point to note here is a point about wet-hulled green coffee being recognisable by its “dark-green and patchy colour” which may also be described as blue. I’ve certainly noticed this in the green coffee I have purchased which was processed in Sumatra, and it is very bluish in colour — quite noticeable compared with green coffee from other regions around the world.

I’d highly recommend reading the original article on Perfect Daily Grind, as it goes into considerable detail around the origins of why the processing is used, possible defects, and advice for getting the most out of these types of coffees (including roasting).

Semi-dry processing methods

Although not typically a category you often see listed individually, semi-dry processing does use significantly less water than the washed or semi-washed methods described above.

Pulped natural

Pulped natural processing is apparently a common method used in, but not unique to Brazil — and you will certainly see this description on coffee originating from other countries. The actual stages are similar to the washed process described above, however the mucilage is removed with a pressure washing apparatus (taking care of steps 2 and 3 above), which removes the need for fermentation.

Without requiring large tanks and significant water for fermentation, the pulped natural method doesn’t quite fit in the wet processing category, however it is not fully dry either — therefore ending up in its own semi-dry category.

I must also point out that up until this point, I had not really looked closely at the subtle differences between pulped natural and honey methods of processing, however they are distinctly different, given the mucilage is removed in the former, however remains on in the latter (described further below).

Although consistency is apparently increased with pulped natural processing, as the risk of too much or too little fermentation is eliminated, thinking goes that this consistency possibly comes at the expense of flavour. Pulped natural coffees commonly tend to have lower levels of acidity in their flavour profile.

Dry processing methods

Natural

Natural processing is probably the most common of the dry methods, and involves leaving the coffee cherry intact, sun drying, then removing all outer layers from the bean:

  1. early_cherry_natural_processThe coffee is harvested, and in some cases drying has already been allowed to commence on the tree;
  2. The pulp or flesh is left on, and the cherry is dried intact, with drying completed on raised beds or patios until the desired 11-12% moisture level is achieved;
  3. The entire hull (dried pulp and parchment layer) is then removed mechanically;
  4. The remaining seed or green coffee bean is then ready for export.

As you can see, this method is the simplest in the form of steps or intervention required, however I am certainly not suggesting it is necessarily easy to do well.

Honey

Honey processed coffees are a further subgroup of those classed as naturally processed, containing additional sub-groups based on specific criteria. This method originated and became popular in Costa Rica, progressively spreading to other countries in recent years.

The term honey is believed to have derived from the stickiness of the mucilage on the outside of the bean, which has a honey-like texture. Believe me – its sticky alright. Here is a short video demonstrating this to some degree, as producer Graciano Cruz of Los Lajones Estate talks about the honey processing method.

Farmers may separate their crop after harvesting, with the aim of developing different flavour profiles based on varying the amount of mucilage left on the bean and altering drying times. These discrete groups provide the various classes of honey processed coffees:

  1. White honey — all mucilage removed from the coffee seed; sun-dried uncovered
  2. Yellow (or golden) honey — approximately 50-75% mucilage removed; gains a yellow colour; dried in minimal shade over 7-10 days;
  3. Red honey — approximately 25-50% mucilage removed; longer drying time and perhaps combined with cloud/shade cover; dried over 14-21 days;
  4. Black honey — no mucilage removed; 100% of the sticky outer coating remains over the seed; covered to elongate drying time up to 30 days.
3_honey_coffee_colour

Adapted from Cafe Britt, showing (L to R) yellow, red, and black honey colouration after drying.

A point to note on the above list: most articles on honey processing will point to variations that occur from mill to mill or between individual producers. For example, I have seen descriptions indicating black honey processing involves drying the beans covered, with a relatively quick drying time — yet others suggest the drying time is longer. The percentages above are also approximations based on different articles I have read on the subject.

Why use dry or semi-dry processing methods?

For me personally, the answer is a simple: because I am interested and would like to see how things turn out. On a larger, professional scale, the reasons are obviously very different, and in a competitive marketplace, are a little more involved.

Perhaps to oversimplify things a little here, the answer seems to come down to two main aspects: flavour and environment (in which I include both climate, and the producer’s location and built environment — that is, access to technology and logistics around production etc).

When we talk of flavour (obviously quite important in the coffee game), Timothy Hill, of Counter Culture coffee summarises the flavour thinking in relation to natural processing:

With the natural processing, you’re letting the fruit and the nutrients from the skin and the sugars go into the seed through the drying process

In general, there seems to be the philosophy whereby natural coffees are a truer reflection of the flavour of the coffee cherry itself. This is not to say washed coffee holds none of these inherent characteristics, however from a consumer’s perspective, it is not often the two can be directly compared. In saying that, more producers seem to be showcasing different processing methods of similar or same harvest lots side by side.

As far as the other factors I have mentioned in relation to climate, technology, environment and overall capacity of the producer, Hill also goes on to note:

…the setup cost is extremely low—you don’t have to have a pulper, concrete, the machinery, electricity to run it — if you’re running a pretty large-sized farm. The labor and how to do it right is really tough. So it definitely is easy to take on; it’s really hard to do well.

And from Sweet Maria’s on climate suitability:

Natural coffees are perhaps the original method to process coffee. If the first coffee grown as commercial crop, for trading, was in Yemen, the climate is well-suited to dry processing. The western parts of Ethiopia such as Harar are traditional dry-processing areas. Older coffee-growing areas of Brazil as well as newer ones (Cerrado) have distinct seasons ideally suited to dry process method. If a farm can dry coffee from ripe cherry to hard, dried pod in 20 days, it is probably well-suited to DP (dry processing) methods.

Compared to washed processing, the natural method is clearly better suited to areas where water might be a scarcer resource, given its considerable utilisation in the various stages of the wet processing method. It then flows on, that drier (read less humid) climates would also be well suited to natural processing, which they appear to be.

Clearly in my humble backyard experiment, set up and ongoing costs are not a consideration at any scale, however with the coffee tree in my backyard now over a metre tall, there will be a time in future when processing considerations come into play. Although my time and effort required to process any coffee I produce will be a consideration, I suspect the local climate will perhaps dictate which method might be best overall.

The Experiment

Although I have called this series of posts a natural processing experiment – I use that term fairly casually. The plan is to outline in basic terms the methods I’ve used; data collected; recount how things turned out; and perhaps consider what I may do in future. What you won’t see are the usual scientific journal headings under which these components reside, nor a formal write-up with p-values, correlations, effect sizes or the like.

In simple terms, what you’ll read about is how I had a crack at it, followed by a tale of what happened.

Considering my natural processing options from those listed above, some thought was given to whether the methods used would be readily reproducible; easy enough to accomplish in terms of equipment, technique and time; and amenable to some type of tracking. Finally, it would be nice to utilise more than one type of processing and perhaps compare the two outcomes.

Of course there were some limitations in what I planned to do — climate for one. Many articles mention humidity as an “enemy” of natural processing, with Indonesian producers having adapted their methods to account for this, as I’ve described in the wet-hulled processing above. Although I have no real control over this, the drying period occurring in late spring provided some hope of finishing this phase before the full brunt of Brisbane summer humidity arrived.

Also, I have no real means of measuring the moisture content of the beans, with devices capable of this more expensive than what I’d be prepared to outlay at the current point in time. It is also beyond the scope of what I wanted to do, however would have provided decent points of reference for both data monitoring and as an indicator of when the process might be done. To that end, based on what I had read to date: “that seems long enough” would have to do.

In the end, I decided to try natural processing (entire cherry intact and sun-dried), along with a sample of the honey processing method, most closely aligned with what I have described as “black honey” above (pulp removed, with the entire mucilage remaining on the outside of the bean). In retrospect, the black honey method may not have been the wisest choice in a humid drying environment, however trying to remove some of the mucilage first and to what degree, did not easily satisfy my “ease of use” criteria — whereas removing the pulp and simply leaving them did.

IMG_4931

So things were now underway. A small lot of coffee cherries halved into even smaller batches, one natural and the other honey processed. Hopefully I have done a reasonable job above in explaining the basic differences between methods to provide you with some understanding of each — no doubt many of you will already be fairly familiar, however I though it would be a good starting off point.

Future post(s) will report back on progress and ultimately the outcome of my own little experimentation into natural processing methods — hopefully you’ll check back in and see how things went.


Third Wave Wichteln 2015

2016-01-18 tww_logo

Image courtesy Third Wave Wichteln

Scrolling through the thirdwavewichteln hashtag on Instagram and Tumblr or in the Facebook group of the same name, I see packages of specialty coffee continuing to finally reach their intended destinations around the globe.

Bon(n) voyage!

Bon(n) voyage!

It is the second time I have participated in the Wichteln, and my parcel containing a bag of Washed Ethiopia Dumerso roasted locally by Coffee Supreme made its way successfully (confirmed via the social media pages noted above) to Bonn, Germany. I may have also thrown in a bag of the same coffee (this time Natural Process) roasted by yours truly — something I wouldn’t probably describe as a “bonus” necessarily, in the hope the recipient might enjoy comparing the two. Thankfully, Facebook tells me both were well received.

2016-01-18 tww_reanimato frontIn return, I was lucky enough to receive some superb Costa Rican coffee: Divino Niño, from ReAnimator Coffee Roasters in Philadelphia, USA — a little more on this below.

If you have not heard about Third Wave Wichteln, it is a global specialty coffee exchange which occurs each year in December/January, where, at random (after signing up) you are matched with a recipient to send your coffee to, and your name given to another (different) member to receive some in return.

I think most of us know the principle — from Wikipedia:

Secret Santa is a Western Christmas tradition in which members of a group or community are randomly assigned a person to whom they anonymously give a gift … and is known as “Wichteln” in Germany. “Wichteln” is what a “Wichtel”, a wight, does, a good deed.

I wrote a few thoughts down about the nature of the online communities many of us are involved in after last year’s exchange .

Unfortunately for some, the programme does not quite reach a 100% completion rate (now with over 2000 members around the world taking part). Through the vagaries of international postage, customs, and also perhaps a little misunderstanding in some cases about what constitutes an appropriate coffee to send, the Facebook feed is also home to a few criticisms of the programme.

Just a couple of things on this point. There have been some calls within the Facebook group for the organisers to provide the email addresses of the assigned sender to those still waiting, where it appears the coffee is lost or indefinitely held up somewhere.

To their credit, the organisers have repeatedly confirmed they will not take this course of action, citing a priority on members privacy, and reaffirming the programme is based on trust. I applaud them for this stance and strongly agree on both points.

In my view (and yes — easy for me to say having received great coffee each year so far), entering into a programme such as this must be based on giving (isn’t that in keeping with the spirit of the season in the first place?), with an expectation you are more than likely to receive in return.

Whether by global exchange or within your office, we’ve all been the recipient of the random joke. You know, you carefully decide on an appropriate gift for the random pool, and then find yourself on the receiving end of the completely useless novelty shop item meant to give everyone a good laugh. Very unfortunate, but it happens — and bear in mind that was the giver’s intention. In the case of the Wichteln here, I’m sure the coffee was sent with the utmost of good intentions, and for some reason beyond the control of the gift giver, simply never arrives — again unfortunate but hardly the fault of those involved.

I say again — treat the Wichteln as a programme of giving and you really can’t go wrong. Stock up over the holiday season on your favourites, or from roasters you have not tried before and get stuck into enjoying those coffees. If your package from across the world drives? What a bonus, otherwise forget about it and it will be a nice surprise when it does land on your doorstep.

Oh… the coffee itself?

2016-01-18 tww_reanimator_backAn absolute delight, with some handy advice on brewing parameters from the ReAnimator barista and trainer via Twitter who sent me the coffee as well (thanks again Greg!). Yes — it really isn’t hard to connect with those whom you have sent to, or received from, once the exchange is complete.

2016-01-18 tww_iced_filterThe Divino Niño certainly lived up to its promise, a sweet, juicy brew, perfect through the V60, in the Aeropress, and on a particularly hot Brisbane summer day, an iced filter which possibly even outshone the other two. I most definitely consider myself a very fortunate recipient.

If getting involved in something like this is of interest to you, visit the website, where there are some specific, yet straightforward instructions on the type of coffee to send and how to send it.

I’ll certainly be signing up again next December and will be looking forward to sending some coffee to a lucky recipient across the globe — and I’m pretty sure I’ll receive something special in return.


What’s Brewing: Ethiopia Dumerso Natural Process

IMG_5204This particular coffee from the Yirgacheffe region in Ethiopia originally came into my possession in September of this year, part of an order from Ministry Grounds, my usual green bean supplier. The coffee was quick to position itself atop the heap as one of the best of the year for me.

With an eye towards the 2015 “Christmas Roast” festive blend, I quickly added another kilogram to the next order in November.

The Region

The Dumerso mill is located within the Yirgacheffe region of the Gedeo Zone in southern central Ethiopia, bordered on the south by Kochere, west by the Oromia Zone, north by Wenago, east by Bule, and southeast by Gedeb (courtesy Wikipedia).

Local roaster Coffee Supreme also tells us:

The Dumerso municipality has around 700 smallholders contributing their coffee, each bringing with them the unique characteristics of the areas heirloom seed stock

The Coffee

Courtesy Ministry Grounds:

The Natural process involves the ripe cherries being delivered to the mill where they are sorted and graded, then placed onto raised drying beds in thin layers and carefully turned every 2-3 hours. 6-8weeks later, depending on weather and temperature, the beans are then de-hulled ready for export

  • Ethiopia Yirgacheffe Dumerso Gr 1
  • Region: Yirgacheffe, Southern Ethiopia
  • Varietal: Heirloom – Ethiopian
  • Altitude: 1800-2000 metres
  • Processing: Natural, Sundried (Kebel Dumerso Mill)
  • Tasting notes: A beautiful, balanced and natural coffee; sweet with dominant notes of strawberry and other berries; creamy body and a tropical finish.

The Brew

I mentioned in the introduction this coffee quickly became one of the standouts for the year, mainly due to its great performance across virtually all of the brewing methods I prepared it with.

IMG_5328Upon opening the bag, and of course after grinding, the aroma was akin to plunging head first into a bowl of mixed berries, of which the majority were strawberries. This of course followed through into the taste as well. Given the 2 kilograms of green beans I had at my disposal, I was able to tailor the roasts for both filter and espresso brewing.

As espresso1, there was a fantastic combination of ripe berry flavours and raisins, with just a little chocolate. Also evident was a smooth creamy mouthfeel, medium body and long finish. Used as a base for a latte or flat white, similar flavours were again on show, with the overall combination somewhat reminiscent of a cherry ripe bar.

When roasted a little lighter and filter brewed with the V602, you guessed it — predominantly strawberry, this time a little lighter and brighter, with a hint of jasmine and a little citrus to the finish. Again, that creamy-smooth, velvety mouthfeel.

Lastly, amidst the afternoon office kitchen rush, the Aeropress3 again saved the day, providing enough of a pause to allow my enjoyment of a similar flavour profile. Although not quite as bright as the V60, that smooth creamy mouthfeel, strawberry, and jasmine on the finish again made for a very enjoyable cup.

The Finish

IMG_5341So all in all this coffee was certainly one of the best for the year, and as a result contributed 60% of the “Christmas Roast” festive blend overall volume, in combination with a washed coffee from Honduras (El Tamarindo Horizontes) and a honey processed offering from El Salvador (La Esperanza).

Overall I was fairly pleased with how the blend turned out, a main aim being to keep the great Ethiopian berry flavours of the Dumerso at the forefront, whether brewing with an espresso base of through a filter.

I think you can probably tell I enjoyed this one, and it was nice to end the year on a high note from a coffee perspective.

Having now turned over into 2016 (and a happy new year to all), things have kicked off pretty well with my Third Wave Wichteln coffee arriving a couple of days ago — a beauty from ReAnimator Coffee in Philadelphia, kindly sent over as part of the exchange by Greg, a barista and trainer with ReAnimator.

IMG_5283Speaking of the Wichteln, you might be able to guess which coffee I sent to Bonn, Germany to fulfil my part of the exchange. It was indeed the Yirgacheffe Dumerso, however this time the washed process coffee, roasted of course by the professionals at Coffee Supreme. Hopefully the recipient will enjoy it, and also (fingers crossed) the additional bag of my home roasted Dumerso Natural thrown in as well.

I’ll leave it there, except to say I hope your journey (coffee or otherwise) into 2016 begins well and continues — lets say for at least twelve months or so. Now I’m off to brew!


 

  1. Dose 21.6 grams; yield 44 grams; time 27 seconds ↩︎
  2. Dose 19 grams; water 330 grams; brew time 3:15 ↩︎
  3. Inverted; dose 16 grams; water 200 grams; bloom 30s; brew 30s; flip and plunge 30s. ↩︎

Crop to Cup: The Complete Series

A little over two years ago I published a series of five posts outlining my initial foray into coffee processing. The technique I used at the time was a wet or washed method of taking recently picked coffee cherries through various stages to the point of roasting. While the end result was not outstanding in the cup, having been given the cherries with no information as to their exact source, type or quality, the whole process was always going to be a little hit and miss.

In saying that however, I was quite happy with how the actual processing techniques proceeded. I must admit to having quite an experienced mentor in the form of my mother, who has now been processing the coffee grown in the backyard for a number of years, culminating in a first place at the local Agricultural Society annual show just a few weeks ago.

As I am currently in the middle of experimenting with some natural processing methods, I thought it might be worthwhile combining those five posts (originally titled Crop to Cup Parts 1 through 5) and republishing them together. Hopefully what follows will provide a little context, and also highlight some of the differences between the two styles of processing when I eventually write about what I currently have underway.

Although none of the original posts were excessive in length, I have included a table of contents should you wish to jump to any particular section of the article.

What follows is essentially unedited from what was originally published, except to improve the formatting and for clarity. I hope you find it as interesting to read as I found it going through the process.

Table of Contents:

1. Introduction, Pulping, and Fermentation

2. Transition to drying

3. Drying

4. Parchment Removal (Hulling) and Roasting

5. Tasting

1. Introduction, Pulping, and Fermentation (Top)

photo (1) While the title of this post may sound rather exotic, the reality is I have been lucky enough to be given a small, recently harvested crop of beautiful red coffee ‘cherries’. Receiving such a gift carries significant responsibility, and I am determined to process, roast and cup the resulting brew with all the dedication and care I can muster. As regular readers will know, I have been roasting at home for some time now (purchasing green beans online), however to this point have not processed beans straight from the tree.

This is a whole new ball game for me. How to proceed?

photo (3)photo (2)

The first step was a call to my parents, who grow, and therefore regularly process, roast and drink their own crop. Next, an internet search to see what is out there on this topic. I was surprised to find the most helpful instructions on my state government’s Department of Agriculture, Fisheries and Forestry website. For additional reading on the types of processing methods, the International Coffee Organisation (ICO) provides a good summary.

Wet or Dry Processing

Firstly, there are two options, wet or dry processing. What follows in the section below outlines the wet processing method I plan to use, said to “better preserve the intrinsic qualities of the bean”. This method is the one outlined on the state government website, and also the one my parents use.

In the dry processing method, the entire coffee cherries are dried in the sun for approximately 4 weeks (to a minimum 12.5% moisture content), followed by removal of all outer layers around the bean by hulling equipment. States the ICO:

The dry method is used for about 90 percent of the Arabica coffee produced in Brazil, most of the coffees produced in Ethiopia, Haiti and Paraguay, as well as for some Arabicas produced in India and Ecuador. Almost all Robustas are processed by this method.

Wet processing generally follows the procedure outlined below, though obviously on a fairly large scale for commercial operators. As opposed to the dry method, the seed is extracted and fermented first, the drying process then follows, again until the beans reach 12.5% moisture content. The beans are then stored, and the hulling process is completed just prior to export. Again from the (ICO):

The wet method is generally used for Arabica coffees, with the exception of those produced in Brazil and the Arabica-producing countries mentioned above as users of the dry method. It is rarely used for Robustas.

My wet processed micro lot

The wet processing technique I am using involves the following steps:

  • Pulping
  • Fermentation
  • Drying
  • Parchment removal (hulling)
  • Roasting
  • Brewing

Comparing the method my parents use with those online saw many similarities, with only some of the time frames differing a little in each stage. Today we will look at Pulping and Fermentation, and return in future posts as my drying process proceeds.

Pulping

Seed extraction in the pulping phase.

Seed extraction in the pulping phase.

Here we are removing all of the skin and pulp (flesh) from the cherry, and extracting both halves of the coffee ‘seed’ from inside, and should occur as soon as possible after harvesting. Be sure to discard any under-ripe (green) or overripe (black) fruit which will reduce the quality of what ends up in the cup.

This process can either be done by hand (squeezing each cherry between your thumb and finger), or in the bottom of a bucket using a piece of wood to squash the fruit, resulting in the seeds being forced out from the flesh. Adding water will then allow removal of the skins and one other critical element – any floating beans. Good coffee beans will not float, and those that do should be discarded as they are unusable, and will spoil the batch.

Removal of floating beans (left); fermentation (right).

Removal of floating beans (left); fermentation (right).

Fermentation

There is not a lot to say about this step, apart from the fact it should last anywhere from 18-48 hours to a few days, and involves natural enzymes breaking down the ‘mucilage’ (the outer slippery substance) around the parchment layer. Fermentation should be done in a plastic bucket or container (metal may affect the taste), with the entire bean mass covered by water. To test for completeness of this phase, washing a small amount of beans should see the ‘slippery’ coating disappear, resulting in a clean, gritty feel. If so, agitate and wash the remaining beans until he water is clear (again removing any that float), which may take several washes. Once washed and clean, the beans are then ready for drying.

At the time of writing this post, the pulping is completed, and the beans are sitting fermenting…

2. Transition to drying (Top)

Coffee drying in the sun. Dolka Plantation Cos...

Coffee drying in the sun. Dolka Plantation Costa Rica (Photo credit: Wikipedia)

With the fermentation phase now complete, we move on to the drying phase of processing. You may remember from the first part of this series, coffee processing is broken up into the following stages, as described by both the Queensland Department of Agriculture, Fisheries and Forestry, and my mother, who is very experienced and knowledgeable in these matters:

  • Pulping
  • Fermentation
  • Drying
  • Parchment removal (hulling)
  • Roasting
  • Brewing

At the completion of Crop to Cup Part 1, we left the beans fermenting in water at stage 2 above. I was a little unsure of how long this may take (72 hours or up to a week), though armed with the knowledge this phase would be complete when the mucilage (slippery outer layer) was easily rubbed away. Daily testing was undertaken, until on day 7 (exactly as predicted by my mother), rubbing one of the beans between thumb and finger resulted in a slightly gritty/pebbly feel rather than a slippery one.

Time to move on to drying.

Drying

Once the beans have fermented for long enough, they are required to undergo a final wash and rinse, before being laid out on drying beds. In aid of passing down the coffee loving tradition to the next generation, my son was enlisted to rub off the mucilage, with repeated washes then performed to remove any remaining on the outside of the bean. Agitating the beans and replacing the water over three washes was sufficient to achieve this. Washing

Looking back to our Department of Agriculture guide, the drying process is described as follows:

The beans should be spread out in a thin layer no more than 3 cm thick, stirred three times a day, and be protected from rainy weather. Drying in this way can take 5-30 days, depending on the seasonal weather pattern.

As you can see below, an initial drying of the beans was done on a small towel, before transfer to a drying rack to allow plenty of airflow around the beans. The rack is situated under cover to avoid any weather or dew, however sees the mid to late afternoon sun, which should assist with drying. Given the small crop I am processing, a single layer of beans was placed on the drying bed, with little chance of any mould formation (the reason for stirring daily), though I aim to ensure the beans are turned regularly.

Drying

I hope you will join me in a couple of weeks for the next post in this series, where we will be up to removing the remaining parchment layer and roasting our crop!

3. Drying (Top)

photo (4)

The first two stages of this process were outlined in Parts 1 and 2 of this series, along with the initial phase of stage 3, in which today we learn that patience is indeed a virtue.

Drying continued…

Every day I walk past my drying rack, checking (and turning) the beans, as the remaining moisture is drawn out, courtesy of the great weather we have been having of late in South East QLD. No rain to speak of (though many gardens need it), and fairly low humidity (compared to usual levels) have made for what I would consider perfect ‘bean drying’ weather. Although the beans have been undercover and would not be directly affected by rain, the increased humidity and overall moisture in the air would likely have required a longer period of drying.

The ideal drying time?

For further information here we again refer to our two main sources: The Department of Agriculture, Forestry and Fisheries (DAFF)

Whichever method of drying you use, the parchment on the coffee bean will dry to a pale straw colour and be brittle to touch. At this stage, test the dryness of the beans by removing the parchment by hand off several coffee beans. If dry, the bean inside should be greyish blue in colour, hard, and likely to break when bitten between the teeth, if not soft and chewy. If soft, continue the drying process.

The “methods” of drying referred to above include the natural sun drying method I am following, or alternatively, a food dehydrator, which must be kept at 40 degrees celsius over the course of several days to complete the drying. Whilst a dehydrator may be a more rapid method of drying, some of the romance is lost, if I imagine hundreds of square metres of beans drying in the sun on a Colombian hillside. Though the strength of this argument wanes a little when my entire crop fits into my palms cupped together. Anyway, for the current crop, sun drying it shall be.

…and from my mother:

I usually leave it at least two weeks to dry out. Sometimes you might get away with 10 days or so, but two weeks just to be safe. Your best guide is to crack off the parchment layer with your thumbnail, and if you get a good split or cracking noise you can be fairly sure it is dry enough. Once I have removed this layer and simply have the green bean, a couple of days more drying will really finish them off.

We agreed that my planned two further weeks (making four in total) drying time would not be to the detriment of the end result (that is, be too long). The four-week time frame is due to a holiday occurring in the middle of this process, rather than specifically planning a drying time of this length. I do note however this does coincide with the upper end of the 5-30 day recommendations of the DAFF.

Drying – Two Weeks In

As noted above, after two weeks I am now half way through my planned drying time and testing a couple of the beans would appear to show that everything is on track. You will see in the picture below that the outer parchment is quite dry (it also comes away from the inner bean with a nice crack when pressure from my thumb is applied).

photo (5)

Referring to the DAFF instructions above, the bean is blue/grey in colour and feels reasonably hard, though I did not see the need to give it the ‘bite test’. In another two weeks I would expect the beans will be well and truly dry and begging to be roasted, at which time I will provide an update with another post.

In the mean time, have a look at my magazine Brew – Ways of Coffee on Flipboard for some great articles I have collected from around the web.

4. Parchment Removal (Hulling) and Roasting (Top)

The fourth instalment in this Crop to Cup series looks at the final steps of processing, followed by the roasting of our “microlot” of coffee, kindly received straight off the tree from a barista friend about a month ago. As with anything, good things come to those who wait, and four weeks after starting, we are almost to the point of tasting the fruits of our labour.

To date, we have worked our way through Pulping, Fermentation (Crop to Cup – Part 1), Drying (Crop to Cup – Part 2), Drying again (yep – it took a while) (Crop to Cup – Part 3), and we continue on below.

Parchment Removal (Hulling)

In Part 3 of this series, drying continued in preparation for the final “hulling” or parchment removal prior to roasting. After a further two weeks drying (four in total) it was time to remove the parchment layer.

As I have written in previous posts, the beans being “dry enough” and the parchment ready for removal, is determined both by observing an appropriate drying time (approximately two weeks to a month), and having the parchment split easily off the inner bean upon attempted removal. According to the Department of Agriculture, Fisheries and Forestry (DAFF):

Inadequate drying – greater than 12 per cent moisture – will cause mouldiness and stale aroma during storage.

Upon proceeding with the hulling by hand (or rather thumbnail and finger), it is clear this is quite a labour intensive undertaking. After 1 hour, the parchment layer was removed from our crop, and we were a step further along in the process.

Photo 13-10-2013 5 41 17 am

Given the time and labour intensive nature of this part in the process, the DAFF suggests the following:

Place the beans, a small quantity at a time, in a food processor or similar type of blender. Use plastic blades to avoid breaking the coffee beans. Blend at low speed for approximately 30 seconds to remove the parchment from the beans.

My mother uses a similar approach, blending on low-speed for 8-9 seconds, which she finds removes much of the parchment layer without damaging the green bean inside. Whether done by hand or machine, you will be left with a fine outer layer of “silver skin” remaining on much of the bean. Enlisting the assistance of my son to provide a quick rubbing of the beans between his hands removed this final layer. Blowing away any remaining silver skin completes the process.

Photo 13-10-2013 5 47 51 am

We were now ready for roasting!

Roasting

With a dry weight of 35 grams, there was certainly no margin for error, and had me thinking I really should be calling this a “nanolot”, as “micro” probably doesn’t go far enough (yes an hour of hulling for 35 grams of green beans – as I said – very labour intensive!).

So proceed with care I did.

Photo 13-10-2013 6 01 02 am

The roast was undertaken via my usual breadmaker / heat gun set up which I have previously written about. The heat ramp was very slow, and the total roast time 12 minutes, with the beans pulled out 3 minutes after first crack. The result looked like a pretty even roast, and was cooled and bagged. A few days rest and it will be ready for tasting.

Photo 13-10-2013 6 07 14 am

Check back soon for the much-anticipated taste test!

5. Tasting (Top)

Photo 22-10-2013 4 25 25 am

Here we go, the finale in the Crop to Cup series, where we sample the end result of the past 6 weeks caring for and nurturing (let’s be honest – processing) our microlot of coffee beans. As you can see by the image above, it was going to go one of two ways. Over this time we have worked through pulping and fermentation (Crop to Cup – Part 1); drying (Crop to Cup – Part 2, and Crop to Cup – Part 3); and hulling (Crop to Cup – Part 4) prior to roasting.

After such a long process, my concern was that I would be somewhat biased about the result. Also, given I had such a small amount, how was I going to brew? After setting aside half of the massive 27 gram (roasted) crop to return to the generous barista who gave me the coffee cherries in the first place, only enough remained for a single brew, whichever method I chose.

After much deliberation, I went with my Hario V60. My rationale being I wanted a method that would allow me to assess the coffee on its own merits rather than being combined with milk, and in the knowledge that the returned beans to my barista friend would be tasted as espresso. The V60 seemed like a good fit as I would be able to enjoy six or so weeks worth of care and attention for a little longer, rather than having an espresso that was both created and consumed in a flash. Though in saying that, I would also be in for a longer period of disappointment and torture if the resulting brew was horrible.

Photo 22-10-2013 4 30 44 am
So, how did it turn out?

The Taste Test

The coffee

Jen’s Australian Microlot
Harvest Year: 2013
Wet processed; sun-dried
Sorry, no further information regarding the exact origin of these beans!

Method

Hario V60 Pourover

The Result

The section I have been waiting to get to for some time now!

In summary, the resulting brew was fairly ordinary, however drinkable nonetheless. Overall, it lacked any real body and had minimal sweetness, even as the brew cooled. Underneath there were some very mild floral and herby notes doing their best to be tasted. Accompanying these were some earthy flavours which thankfully did not overpower the brew, though lingered in an aftertaste that was a little, shall we say … strange.

Generally speaking, none of the flavours really overpowered the brew, making it a little “flat” overall. Given the light to medium roast of the beans, perhaps in retrospect I should have roasted them a little darker.

Feedback from my barista friend on the espresso experience was not positive at all. The concentrated form of an espresso shot seemed to magnify everything that was wrong with the beans, particularly the lack of any discernible body. I am told it was quite a flavourless experience.

Conclusion; Know This

In conclusion, although a little labour intensive, processing from the original cherries into something I could roast and then brew was a very satisfying experience. Yes, the taste test above did not reveal anything outstanding, however the brew was certainly drinkable and knowing that both the roast and brewing variables could be tweaked and improved if more of the “raw materials” were available was a promising sign for any future attempts.

I must also note here that I am comparing this with some fairly high quality beans I routinely purchase from Ministry Grounds Coffee, my usual supplier.

If you have followed this 5 part series, thanks for sticking with it over the past couple of months. I hope it has given some insight into small batch coffee processing had you not already experienced it yourself. For me it will be back to the usual roasts and posts. I’m not sure if the labour intensive nature of processing from scratch suits my lifestyle. Then again, my mother did say there is a nice young coffee tree in a pot she is saving until my next visit.

Perhaps I am about to become a grower as well…


Using Day One to Track Coffee Processing

hero-dayone-icon@2xSometimes I get the feeling Day One is used by many as everything but a standard journaling app — and I certainly mean that in a complimentary way. I’ve previously written about how I use the app for logging workouts (the recent regularity and frequency of which we won’t talk about if you don’t mind). Since that time, Day One has been refined and updated, yet retained its core features and attractive UI which so many users have come to love.

As the title of this post suggests, this is not a review of Day One as such — more so another in that long list of use cases I’ve linked to above, in which the app excels at being used for a specific purpose.

Exactly two years ago I ran a little experiment on coffee processing using the wet or washed method, and documented the experience in a series of posts titled Crop to Cup.. I am currently in the very early stages of a follow-up experiment to see how a small crop of coffee tastes after I process the fruit using dry processing methods. Clearly an undertaking which requires monitoring and data collection along the way — enter Day One.

What is Day One?

Although I am sure most readers are well aware of this beautiful Mac and iOS App, however for those perhaps not yet acquainted, the developers is summed up by the developer as follows:

Day One is a journaling app for the iPhone, iPad and Mac. Record life as you live it. From once-in-a-lifetime events to everyday moments, Day One’s elegant interface makes journaling your life a simple pleasure.

I’d certainly agree with that sentiment, though I’d encourage you to see what the fuss is about for yourself if you haven’t already. Of course there is a significant amount of information on the Day One website, however for a review about as beautiful as the app itself, there is none better than this one over at The Newsprint.

The project

Nat process_publish

As I mentioned above, coming up in a post or two in the near future will be my attempts at a small experiment in dry processing of some coffee grown in the yard of my parents house in northern NSW. The coffee will be sun-dried with either the entire cherry intact (“Natural” process) or with the outer flesh removed first(“Pulped Natural” or “Honey”) process. More on this in future posts.

Although hardly a large-scale endeavour (or an overly professional one for that matter), I will need a record of how things progress over the course of approximately a month as the coffee transforms from its current state to something resembling being done1.

In considering my options here, when thinking about recording recurring data over a number of days, my thoughts invariably turn to spreadsheets. Immediately thereafter my thoughts then turn to the fact that I am buried in spreadsheets on a daily basis and considering combining an enjoyable hobby with this type of data analysis makes my stomach turn a little. If a spreadsheet was by far and away the best solution I would of course use it, however when other options are available I’d prefer to head in another direction.

Why Day One?

Ideally, I’d prefer something much more attractive and enjoyable to use for recording this data. Upon thinking about the sort of information relevant to my aims, the first items on the list are a daily photographic record and weather data, and therefore Day One was the obvious choice. The Day One About page provides a list of the data providing context to each entry:

Each Day One entry automatically tracks:

• Photo EXIF data

• Temperature and weather data

• Locations

• Time and date

• Activity data – Motion and step count

• Music playing

All well and good (with the bottom two from the above list not required here), however what about relevant data not automatically captured by Day One? Probably the key here is the relative humidity (the number one enemy of dry processing), over and above simple temperature data. I assume Day One simply pulls in the system weather information, which in itself, does not include humidity. Manually entering this as not a major issue, with the advantage of having what is recorded automatically by Day One providing a significant head start over a manually maintained spreadsheet.

Regardless of which system I use, there is the requirement for some sort of “Additional Comments” section, and it is here I will simply add the humidity reading (easily obtained with one tap from the best iOS local weather app there is: Pocket Weather Australia), along with information on how often I turn the drying beans (hint — it’ll be often), and anything additional worth commenting on for that particular day.

I don’t anticipate capturing a lot of additional information, as things will be fairly standardised day-to-day, however any significant changes or data outliers/modifiers will be noted specifically. As this additional data will in itself be fairly similar day-to-day, a customised template using Launch Center Pro might also be on the cards.

Nat process entriesNat process sing entry

Of course the non project-critical feature of sharing through Day One’s Publish feature will allow me to Tweet daily updates of the drying beans for your viewing pleasure. No — of course I won’t! Ever watched paint dry? Perhaps the occasional one… maybe. The benefits of organisation by tag, along with rock solid sync and export options (PDF, with entries for export selectable by tag on iOS), will also keep my data organised, safe, and allow a better overview of how things went when the processing is complete.

One feature which would have been nice is the ability to upload multiple photos per entry, thus keeping each day to a single entry2. No real complaints here though, as the Day One Newsletter tells me this is coming (along with refinements to the interface and multiple journals) in version 2.0, which will hopefully arrive before the end of the year.

Conclusion

Overall, Day One is just about perfect for what I require in terms of data collection and handling for a project of this nature and size. It’s a pity there is no “taste guarantee” built in to the app — for that I’ll just have to take my chances.

Irrespective of how things turn out, the entire process will be far more tasteful using Day One for recording purposes than the bitterness of nibbling on another spreadsheet every day.

Here’s to an enjoyable (and hopefully successful) journey, with a glorious cup of “natural process” coffee at the end. Wish me luck.

  1. More detail on this in a future post, for in my typical fashion I am learning as I go here. ↩︎
  2. I could of course merge two photos into one using another app, however this adds additional steps compared to simply opening Day One and snapping away. ↩︎