Crop to Cup – Part 4

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.

4. 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.

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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.

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We were now ready for roasting!

5. 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.

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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.

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Check back soon for the much anticipated taste test!

What’s Roasting #5 – Ethiopian Yirgacheffe and El Salvador Siberia

Ethiopian woman coffee farmer with basket of c...
Ethiopian coffee farmer (Photo credit: Wikipedia)

After aiming my recent roasting efforts towards blending, it’s time to get back to some of my favourite regions and sample some single origins. I will also post a further update in the Crop to Cup series in the near future, as we get closer to roasting and sampling.

So, in searching for a fruity African varietal, this Ethiopian Yirgacheffe came along through the good folks at Ministry Grounds, who also supplied the following roasting advice on this coffee:

Go easy on the heat early on, allowing a gentle drying period. But build some momentum up to the start of first crack. When the beans go exothermic, expect a temp rate drop and try and anticipate this. Not letting the rate rise drop too much will develop the sugars and fruit flavours fully. Don’t go near second crack!

Vista panorámica de la ciudad de Santa Ana (El...
Santa Ana (El Salvador) (Photo credit: Wikipedia)

At the same time I stumbled across a Central American variety in the form of the El Salvador Siberia Pacamara which placed 20th in the 2012 Cup of Excellence, and certainly read well in terms of its potential out of the roaster and into the cup:

Floral with green apple, pineapple and black cherry. Lovely honeycomb and sugarcane sweetness. A balanced cup.

I am looking forward to seeing whether the El Salvador lives up to the usual crispness of varieties from the Central American region, and likewise the usual blueberry explosion of the Yirgacheffe. Tasting review to follow soon.

 

10 Blending Tips for Home Coffee Roasters

Blending

Background

In a recent post I outlined my first foray into creating a roast blend, which yielded reasonable results with minimal planning. As it contained the remaining beans from a couple of previous roast batches, there was no science (nor art for that matter) put into bean selection, consideration of flavour profiles or ratios of each origin, which I expect are required to achieve a blend where the final taste is both a pleasant drinking experience and at least resembles what you set out to achieve.

Some Resources

In this follow up, I will do a little more research into possible ways to improve on my earlier effort. First, a little reading into better ways of blending for the home roaster, where a search will provide some interesting views on the topic, some of which I found quite helpful.

In Coffee Blending for the Home Roaster, Michael Allen Smith presents a number of options in a concise, informative post on blending for the home roaster. These include:

  • Just a Pinch Blend (similar to my initial efforts above; simply what you have left)
  • Checkerboard blend (for successive roast variance and tips on order of roasts)
  • 3 crop roasts (advice on flavour profiles and roast levels)
  • Faking freshness blend (adding newly roasted varietal to extend the life of an older batch)
  • 7 Day Pre-Blending (as it sounds, here the beans a pre-blended and sit for a week which evens out the moisture content which often varies in different origins)

I highly recommend going to the original article, which explains in more detail (without being too lengthy) each of the above points and provides further background on the logistics of putting together a decent blend at home. The final point above does however touch on one of the initial questions I had myself when considering blending – that is, should this be done pre or post roast? A further word on this from Blending Basics at Sweet Maria’s:

If you have an established blend it certainly is easier to blend the coffee green and roast it together. If you are experimenting with blend ingredients and percentages you will want to pre-roast each separately so you can experiment with variations.

For my own situation, and I’m sure many home roasters are in the same boat, consistency of roasts can be a little difficult to achieve at times, so for now I will go with blending post roast. With this approach I have a greater likelihood of producing a pretty good roast on one variety of beans at a time, and will have better control through experimentation over how the final blend comes together.

Another source of information on blending is the Coffee Snobs Blending Room forum, an Australian based forum on all things coffee, where you can work through a myriad of recommendations, questions and answers on the specifics of blending. A great resource for obtaining advice on what proportions or combinations to use for the beans you have available to blend, which can be as simple or as complex as you choose.

These and other sites such as Home-Barista offer examples of blends and the rationale behind each, similar to the following from the Sweet Maria’s article referenced above:

Here’s a great starter blend for a sweeter, cleaner espresso… a sweet blend used at a street level roasterie/caffe in Rome. They use a Guatemala Antigua for the Central:
50% Brazil Dry-process
25% Colombian Wet-process
25% Guatemala or other brighter Central American

Ten blending tips for home roasters:

So, through my 12 months of home roasting experience and a little research, I would offer the following tips for anyone looking to create their own blend:

  1. Read a little (not a lot) on the subject – the aim is to experiment not follow a recipe
  2. Start where you wish to end (what is the final flavour profile you are seeking?)
  3. Have a variety of green beans on hand (or order based on point 4 below)
  4. Have some understanding of the flavour profile and characteristics of each varietal
  5. Know how well each varietal roasts in your own particular set up
  6. Consider medium roast levels to avoid one blend dominating the mix
  7. Begin with no more than three different bean varieties when starting out
  8. Use what you have read to guide initial proportions or ratios
  9. Blend after roasting, where there is unlimited ability to blend, taste, repeat
  10. Blend, taste, repeat (did a say that already?) and enjoy making your own signature blend!

Conclusion

That’s it! My top ten tips for setting out on your own blending journey as a home roaster. From reading around a little, I can say without a doubt there are really no wrong or right answers here, however as with anything, opinions and guidelines exist, your own experimentation ultimately provides the way. Hopefully you will come up with some fantastic blends, as will I in the course of time. If you do, I would love to hear about them in the comments below, or on Twitter.

What is the Roaster? My home roasting setup

Coffee Cherry
Image Fernando Rebelo via Wikimedia Commons

A fair question, given the content of the previous post. The “roaster” in this case, being a very rudimentary set up, and notwithstanding the basic nature of the components, does a remarkably good job of roasting and has not to this point led me to consider changing, after some 12 months of home roasting.

The images you will see in this post, are from my inaugural home roast in May 2012, and despite some minor changes to heat settings used and the rapid cooling process, is essentially unchanged from this first roast.

The first thing I must point out is this method was closely adapted from one posted on the Coffee Snobs forum as the Coretto Method. Though I am not a registered member of this forum (something I should consider), I highly recommend it as a source of information from which to learn more about the humble bean, and am grateful for the detailed instructions in the post which played a large part in getting me up and running.

Other sources of inspiration along the way came via magazine publications Crema and Beanscene, along with reading various articles and sites on the web. You can never do too much research!

Equipment

As you can see in the images below, the “roasting drum” is a second-hand Sunbeam Breadmaker picked up at the local “op shop” for $30.00. The original purchase was made with the assumption that if things didn’t work out, it would be no great financial loss. One year later the breadmaker still churns like a champion. Speaking of which, it would be a good idea to ensure the machine you use has a setting that will keep the paddle constantly moving (in this case, the butter churn setting will continuously turn for 30 minutes, more than enough time for the roast). Some settings may only intermittently move the paddle, thus leaving the bean mass susceptible to local hot spots, and increase the likelihood of burning or uneven roasting.

Roast Setup

The heat source used is an Ozito variable speed heat gun, from the local Bunnings Hardware store, again a $30.00 purchase. This also continues to work well after 12 months of roasting use. I opted for a gun with a continuous variable heat setting under the assumption that I would achieve a better level of heat control, which I do believe is the case. This particular gun has a high/low switch for the fan speed, and an adjustable heat dial at the handle end of the barrel. There are no particular heat increment scales as such (simply a continuous dial), I typically use my own arbitrary ‘hi’, ‘med’, and ‘low’ settings which have been determined along the way through experience and roast results.

A standard box fan on a chair is used to assist in keeping the heat gun cooler during the roast, as well as blowing away any excess chaff shed from the outside of the bean. Clearly this is an outdoor method of roasting, as depending on the bean, there generally is a significant amount of chaff, and the process usually gets a little smoky towards the end of the roast. When the roast is complete, the fan and chair are used to rapidly cool the beans once they are pulled from the drum (refer to The Process below).

The “scaffolding” used to hold everything in place is simply an adjustable saw horse with a clamping mechanism enabling the heat gun to be held in position above the bread-maker, and a piece of plywood spanning the support struts underneath as a platform. Both items were lying around the shed when I initially searched for a way to put everything in position, and continue to do the job perfectly. I have seen various other methods of heat gun suspension, from modified lamp arms to beaker clamps, and even custom-made benches. If you start looking around the house I’m sure you will find something to do the job. Just remember the heat gun barrel will get hot, and clamp it well as the vibration may work it loose if not secured effectively.

Roast Batches

The initial batches were 150–200 grams, over time increasing to 300–350 grams, whereas I now tend to roast in 500 gram bean batches, finding this to be more time efficient. These batches are typically roasted for around 12–15 minutes in total, with first crack occurring somewhere in the vicinity of 7:30 – 9:00 minutes after commencing. The typical yield by weight for the roasted beans is around 84–88% of the green bean weight.

Roast Setup

After experimenting with heat and roast times, I tend to favour lighter to medium roasts, as I find the flavour profile in the cup much more enjoyable, and I am less likely to end up with a burnt flavour from an over roasted batch.

The Process

This has not changed a great deal over the past year, except for minor adjustments, and my current process looks like this:

  1. Set up all components as shown in image above
  2. Record variables (batch size and bean, temperature, humidity, date, time of day)
  3. Turn on both breadmaker (butter setting to maintain constant paddle movement) and heat gun (both heat and fan on high)
  4. Add beans after drum has heated (generally around 2 mins) and commence timer
  5. Monitor for colour changes through initial phases of roast (colour changes generally dictate whether I modify the heat or not), recording anything of note
  6. First crack occurs, usually at around the 7:30 to 9:00 minute mark
  7. Reduce heat setting about 1 minute and 30 seconds into first crack
  8. Roast pulled out generally about 4–5 minutes after first crack or approaching second crack depending on the desired roast level
  9. Tip beans onto a cooling tray, which is a frame of wire mesh (similar to a small window screen – not the bowl seen in the image below as I have found the mesh tray allows a faster rate of cooling) and placed underneath the fan to cool as rapidly as possible for approximately 5 minutes
  10. Transfer beans onto a dry tea towel and spread out for a few hours before packing in ziplock bags with one way valves for storage
  11. Bag and label with roast date and description before resting for 3–7 days prior to use
  12. Record roast data digitally in an Evernote notebook for future reference (where most of the information and the images were retrieved for this post)

Roast Setup

A couple of things to point out in summary. As the process occurs outdoors, the ambient temperature does influence the roast rate, which is why I record this information.

The heat is reduced after the first crack once I have the beans in a good rolling crack, as occasionally there are a few pops that occur in isolation before the main crack occurs in the entire bean mass.

Make sure the beans are fully cool before bagging (see 10 above), otherwise they may “sweat” inside the bags which leads to condensation and moisture, not a great way to begin the storage process for your beans.

Finally, ensure you record data about your roasts somewhere, even if it is just a few notes about how the roast went, time to first and/or second crack, heat settings, and the basic data indicated in 2 above. Whilst you may not need to review this often, I have found it very helpful in comparing different variables to fine tune things for a better roast, or see where things may have gone wrong when things don’t turn out so well. There are many other variables that can be measured and tracked, with tools such as temperature thermocouples and USB data logging programmes for the more technically minded. I have not used these myself, however more information on these can be found on the Coffee Snobs forum link above.

Untitled

So there we have it, my basic but effective home roasting set up and process. I have tried to include some information on what I was unsure of myself when starting out, however do some more reading on this yourself, and at least determine a starting point. Be prepared for a little trial and error after that. If you are in two minds about starting this for yourself, I’d recommend diving in and having go, as for a small outlay initially, you may end up with a setup that works well for a number of years, and there is nothing more satisfying (and cost-effective) than bagging up a kilo of your own freshly roasted beans.

Roast Setup

Go on, you know you want to ….

What’s roasting #1 – Brazil Toffee Cerrado

Today in the roaster we have a South American origin from Brazil, Toffee Cerrado, which arrived last week from my reliable supplier Ministry Grounds, who are based in the lower Blue Mountains, west of Sydney.

I am looking forward to this batch, having previously had some great results with this origin. Though exceptional value for money, most importantly, it brews very well and I will certainly be diving in once the beans have rested a few days after roasting.

A tasting review will follow soon…