Free washed fermentation process part 2 [Coffee Fanatic Hitomi 's Deep Coffee World No. 7]

Hello! ! Coffee Fanatic Hitomi .

Production processing series. I would like to continue explaining the water-washing type, Fully Washed!
Click here for the previous article

Last time, we talked about the differences in fermentation (wet and dry fermentation), and starting from step 3, we will start to introduce applied patterns.

[continued] Variations of Fully Washed

③     Soaking = Double Fully Washed in an outdoor concrete tank
④     Yeast Fermentation by spraying yeast in an outdoor concrete tank
⑤     Cold Fermentation using air conditioning in an indoor concrete tank

It doesn't make much sense just by looking at the text! ! (lol)

So let's go!

Second washing “Soaking”

It's called the "Kenyan style", but I've never heard of Fanatic being called that overseas... However, it is a common production processing method in Central and East Africa, including Kenya.
Soak means to rinse in English, and has the same meaning as rinsing. After fermentation, the washed parchment is returned to the aquarium and submerged in plenty of water. The time is approximately 24 hours.
Well, since fermentation has already finished, I don't think it needs to be done that long, but maybe 48 hours at most?
Because it is washed twice, it is also called Double Fully Washed (DFW).

The water while soaking is very clean ♡ @Costa Rica

Soaking tank in Guatemala El Injerto

By the way, after soaking, the taste will be like this.

The acidity becomes more mellow and the texture becomes smoother. Clean cup improves

Basically, I don't think any negative elements will occur by soaking. It is said that if you use green beans that don't have much potential, the flavor will be diluted, but the clean cup will taste better and the texture will improve. However, the acid structure is a little rounded, so it may not feel as fresh.

It is part of the fermentation process because it is soaked in water, but it is not often used for that purpose. The image is that it is being thoroughly cleaned. However, some kind of fermentation must have progressed to some extent, so perhaps lactic acid bacteria may have a slight advantage. I don't know but... This is one of my personal favorite production processes.

Please note that soaking is a process that takes place after the fermentation process, so the flavor will change slightly depending on the fermentation method used in the previous stage.
The basic method is wet fermentation, but if water sources are not abundant, the amount of water used is high (double(;´・ω・)), so I think more and more places are using dry fermentation.
Even at CWS in Rwanda, there were many places where fermentation was done dry before soaking.

[Water fermentation + soaking]
The acidity is bright and mellow. The texture is smooth and the body is slightly stronger.

[Dry fermentation + soaking]
The basic trend is the same as above. Slightly more sweetness and body


By the way, it's a little difficult to tell the difference between the two based on their appearance, but I think there is a slight difference.

The appearance of soaked green beans is very beautiful. However, since it is exposed to water for a long period of time, if it is not carefully dried in the subsequent drying process, it will deteriorate easily, so moisture management is important.
In Kenya, drying is done on raised African beds, which allows for very clean and efficient drying (this is just drying efficiency, and work efficiency is not that good). African beds are also used in Tanzania, but they often turn white compared to Kenya, perhaps because they are less dry, and they tend to wither more easily.

(Left) Kenya's DFW (Right) El Salvador's DFW... Both look beautiful ♡
(I don't know if it's Photo Shin , but El Salvador has slightly more silver skin)

"Yeast Fermentation" for antibacterial purposes

Sprinkle yeast during tank fermentation. Fermentation using yeast is said to be the method recommended by a professor at Lavras University in Brazil, but it can also be seen in Burundi, Rwanda, and other countries.
Yeast is a type of Shin that is used for the fermentation of alcoholic beverages such as bread and beer, and has anaerobic characteristics (it can work without oxygen). In normal fermentation, nature is left to its own devices, so to be honest, we have no idea what types of bacteria are active and in what proportions to ferment Musillage (*´ω` *).
Using yeast at least eliminates negative effects during fermentation, which reduces the percentage of undesirable bacterial activity. The alcohol in the product also contributes to quality stability. Also, during fermentation, a film of bubbles is generated on the surface of the fermenter, which also contributes to the uniformity of the entire fermentation process.

It is often thought that this is for flavor, but in the case of water-washed products , yeast fermentation is mostly done for the purpose of inhibiting bacteria. So, basically it doesn't add any flavor, but it does sometimes give off a sweet, bread-like nuance during fermentation (it feels really faint...).
It is also used in natural anaerobic fermentation, but it does not have yeast-derived flavors.

Wet fermentation is the mainstream for yeast fermentation. If it's dry, you'll have to stir a large amount of parchment to distribute the bacteria, which becomes a tedious task. As for the taste...

Adds a slight sweetness and slightly increases the volume of the texture.

I once participated in a verification test at a lot in Rwanda. I think the effect is similar to soaking, but soaking is almost the default in African countries, so it may be difficult to determine a single effect. However, there was a difference in the sweetness, texture, and sharpness of the acid between the yeast and the yeast (it's a really subtle difference, but...), so I think it has some kind of effect.

It is a useful fermentation method to suppress bacteria, improve quality, and reduce the risk of damage caused by phenol.

Temperature-controlled fermentation (Cold Fermentation)

I didn't really know the appropriate wording, so I decided to call it cold fermentation. The key is to perform temperature-controlled fermentation.

Once upon a time, producers in Nicaragua fermented mucilage indoors in a climate-controlled environment rather than outdoors. I think the room temperature was set at around 20 degrees Celsius by air conditioning.
Temperatures in production areas tend to rise quite a bit during the day, but the colder the night, the lower the temperature generally becomes, so if you can control the temperature from the peak time of 2:00 pm to the evening, you might not have to spend so much on air conditioning.
Nicaragua Casa Blanca's indoor fermenter (the black pipe on the side connects to the Piñarense system on the other side of the wall)
With this method, the temperature during fermentation does not rise as much, so the fermentation time will be longer. On the other hand, strange rot and contamination with external bacteria will be slightly reduced.
The flavor is a little off due to the long fermentation time, but the quality is stable. So the taste is...('Д').

The texture becomes smooth. On the other hand, the impression of acidity and flavor becomes milder.

Roughly speaking, everything feels "calm". The same goes for soaking, but I feel that if the fish stays in the tank for a long time, the body tends to become a little stronger and smoother.

Dry fermentation can be used as long as the air conditioning is controlled, but the temperature of fermenting parchment increases rapidly, so fermentation using water is easier to control as the temperature is lower.

Also, before this, production processing begins at night, and water is sprinkled on the cherries after harvesting to maintain the low temperature (that's what they call Cold Shower...(;・∀・)) There are also preliminary temperature adjustments such as.

Well, as is the case with wine, beer, and other fermentations, it is common sense to control the temperature. This is because the quality of the results fluctuates greatly (failure = corruption). Therefore, the recent trend among producers seems to be to control the temperature during fermentation.
Especially with Funky Natural and anaerobic fermentation types, when the temperature rises, the flavor goes past the strawberry flavor and goes straight to the soy sauce and miso flavor (lol), so temperature control is important!
There are some special batches out there that claim to be fermented for 48 hours, 92 hours, or 30 days after adding microorganisms, but this does not necessarily mean that longer fermentation times are better. There's no point in cleaning if the clean cup gets low and the fermentation odor becomes dominant, so I think it's important to continue to manage it carefully.


So, I quickly introduced three types!

Next time it will be a mechanical wash!

Hello everyone.
Fanatic Hitomi
Ryo Mikami

Ryo Mikami

After graduating from university, due to certain circumstances, he worked at Starbucks and encountered the potential of coffee. After many twists and turns, he joined a trading company specializing in specialty coffee. He opened his eyes to the Fanatic path and has been involved in a wide range of work from commodities to specialty products, including market price analysis, production site visits, product fair reviews, competition coaching, extraction, roasting, and equipment proposals. CROWD ROASTER advisor.