The key to determining flavor and taste. How does sunshine and washing treatment affect a cup of coffee?

The treatment of coffee before shipment will pre-flavor for the last coffee delivered by the roaster. This life stage of coffee beans is generally called "wet milling", which includes all steps before taking coffee to "dry milling", and the rear bag is ready to be delivered.

The differences in post-processing methods between local areas and farms are very different. Sometimes because they are "traditional methods", they may also be limited by economic conditions or resources. There is another situation, such as the Pulong Land Farmers handed over to the government to the wash station (a total of 150, called sogestal) to be processed further, unlike farming in other countries, where farmers are responsible for all the coffee post-production process.

This stage seems to be routine, but it is absolutely essential. Because of the treatment and evaluation effects of each region, it has opened up a new manifestation of the flavor of coffee beans, which gives the natural characteristics of coffee a completely different performance due to the differences in farming and processing facilities.

"Filtering", usually done in the sink. Overripe and very raw fruits (and leaves) will float up; ripe and immature fruits sink to the bottom of the sink, then extracted and ready to enter the next stage. However, regardless of how careful the harvest is, it is difficult to mix underripe and overripe fruits. Like other fruits, extremely mature or underripe coffee fruits can actually cause poor flavor products - roasters' skills may be difficult to replenish. A slightly underripe or overripe fruit can still meet the minimum requirements of exporters and roasters, but it will kill the cup quality, because only a perfectly mature fruit contains the most sugar and can produce the sweetest coffee.

Whether it is the best quality coffee with the best quality known, or is ready to make instant coffee and the worst coffee beans, you need to clean the flesh and remove the sticky fruit gel. There are two methods: water washing method (moisture treatment) or sun-drying method (dry treatment). Some countries or regions prefer one of them due to climate, economy and other factors, and also have a cleaning method that combines dryness, called pulped natural or semi-washed.

◎Sun-dried coffee, the wild primitive fragrance

The sun-dried process is relatively simple, because all kinds of coffee fruits remain in their original state. The fruit is sent to the yard or trellis to dry, and if necessary, it will ripen the fruit. This process may take several weeks, and you must be careful to avoid bleeding and rotting, but it is normal to have a slight natural fermentation. After it is completely dry, the dark outer layer that has been shrunk must be removed and removed to reveal the coffee beans that are patiently waiting for the appearance. Brazil is a spiritual fortress for sun-dried coffee. Their economic and cultural cultivation has become a way to "eat first and then classify". For example, in the areas of São Paolo and Cerrado, more than 90% of beans are treated with sun-dried.

The sun-dried coffee is not dried, has no external influence, and is "natural", and it has some fruity aroma after being boiled, which looks heavy, messy and wild (usually to an odd degree). However, the brightness of Japanese coffee has changed a lot, and the final flavor produced may not be consistent, and transparency is compromised. Therefore, some roasters avoid this treatment altogether, but the loss of precision may be supplemented by consistency and density, so sun-dried coffee is often an important supporting role among the best functional coffee beans in the world.

◎Wash coffee, bright fruity aroma

Wash coffee, also known as moisture-treated coffee, you must first remove the fresh coffee pulp with machinery (in fact, a large mixer) or a high-pressure water column. In short, the outer layer flesh is pressed and cracked, and the separated coffee beans enter another hole. If you are interested, you can also manually remove the flesh; however, with my personal experience, using my hands is not only slow and dirty, but also difficult to deal with.

The soft coffee pulp was processed before - it had to deal with the fruit layer covered with coffee beans. It was a bit like a paste stuck to the outer layer of the peach pit, which was very difficult. The strongest thing about this layer is made of sugar and fruit gel, which is not only a glue that many fruits contain, but also a thickener that makes fruit sauce and honey thicker.

The way to remove the fruit coating is usually through fermentation - this does not refer to the reaction of yeast and sugar in an oxygen-free environment (such as the wine process) - but to a more general microbial growth process. Coffee beans decompose fruit gel in the fermentation tank by the action of enzymes to form acidic substances, and the overall environment becomes more acidic. The time required for fermentation depends on some factors, and the temperature and the amount of coffee processed can be used to know when the operation ends through experience and the feel of the seeds. The importance of fermentation is not only to remove the fruit coating, but also a process of developing the coffee flavor; the clean and sour layers produced by washing and washing will make it difficult to reach the sun-dried coffee. After slightly washing and removing too much fruit coating, the coffee beans are sent to the shelf or cement floor for about a week.

Although the name of water is very good, it is not a guarantee of quality. The fermentation results are difficult to predict, especially this process completely relies on the microorganisms that naturally exist on the fruit surface and in the water. Flawed beans are not rare. The most notorious one is "stinky beans", whose name is stinky, and its taste is particularly uncommon; if you allow the stinky beans to produce chains, it may easily destroy many kilograms of baked beans.

Different countries and regions will also adopt various specific moisture treatment changes. Take Kenya as an example, it is usually fermented with two-stage fermentation and washed again in the middle; this is why Kenya coffee beans have a particularly bright flavor and fruity aroma..

For farmers, deciding to use sun or water washing is mainly due to economic considerations - washing coffee is usually considered to be of better quality, but requires a lot of water, many sinks, a good piping system, and other special equipment.

As mentioned, most Robusta coffees are treated with sun exposure, which is also economical because this product is already poor, and it is not meaningful to waste resources on improving the product.

※ This article is excerpted from "The Science of Coffee: The Perfect Coffee Classic from Planting, Roasting and Grinding, Temperature Control, Boiling Extraction to Purchase".

"The Science of Coffee: The Perfect Coffee Documentary from Planting, Roasting and Grinding, Temperature Control, Boiling and Extraction to Purchase"

Author: Tristan. Stevenson

Translator: Zhou Peiyu

Publisher: Dialect Culture

Publication Date: 2022/11/30