Crop to Cup – Part 3

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Continued from Crop to Cup Part 1 and Part 2

If you have been reading this series of posts to date, you will know that for my wet processed micro lot I am following the steps listed below:

  1. Pulping
  2. Fermentation
  3. Drying
  4. Parchment removal (hulling)
  5. Roasting

The first two stages 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.

3. 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.

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 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).

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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.

Crop to Cup – Part 2

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

Continued from Crop to Cup Part 1.

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:

  1. Pulping
  2. Fermentation
  3. Drying
  4. Parchment removal (hulling)
  5. Roasting
  6. Grinding, strong and 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 then to move onto drying.

3. 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 is 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!

Crop to Cup – Part 1

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While the above title 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?

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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:

  1. Pulping
  2. Fermentation
  3. Drying
  4. Parchment removal (hulling)
  5. Roasting
  6. Grinding, strong and 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. We will focus on steps 1 to 4, as other posts deal with roasting, grinding and brewing, and in any event, steps 5 and 6 occur independently of the processing method used. Today we will look at Pulping and Fermentation, and return in future posts as my drying process proceeds.

  1. Pulping
    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 underripe (green) or overripe (black) fruit which will reduce the quality of what ends up in the cup.

    Seed extraction in the pulping phase.
    Seed extraction in the pulping phase.

    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.

  2. 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.

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

    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…

To be continued in Crop to Cup Part 2