What Makes Yeast-Processed Red Label Geisha Coffee Beans Special? How Much Does a Cup of Red Label Geisha Coffee Cost?

The Art of Coffee Fermentation

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In daily life, the word "fermentation" often brings to mind making dough for flatbreads, fried dough sticks, steamed buns, or baozi, or it might evoke thoughts of spoiled food or moldy items. Fermentation has found so many applications in our daily lives that it has become commonplace—we enjoy a wide variety of delicious fermented foods, from Huizhou's Mao Tofu and French wine to homemade pickled radishes, Northeast China's sauerkraut with pork, and Swedish surströmming. Everyone knows these come from fermentation.

In English, however, "Fermentation" derives from the Latin word "fervere," originally meaning "to boil" or "bubble." It describes the phenomenon when yeast acts on grape juice or wort, creating a mild foaming or intense activity similar to a boiling state.

Beer Fermentation

Beer is undoubtedly produced through fermentation. The most well-known fermentation reaction in alcoholic beverages is "sugars producing alcohol and carbon dioxide through yeast action." However, beer fermentation is far more complex than just producing alcohol. Various flavors, both pleasant and unpleasant, require precise human control over fermentation environment and conditions to maximize good flavors while minimizing bad ones.

Whether making dough or brewing alcohol, both processes rely on the life activities of microorganisms under aerobic or anaerobic conditions to prepare the microbial organisms themselves, or their direct metabolites or secondary metabolites.

Interestingly, during the beer fermentation process, yeast remains hungry in the later stages. At this point, fermentable sugars may have been depleted, and various fermentation metabolic byproducts all become food for the yeast.

This is when brewers actually control to have more unpleasant flavors consumed and fewer pleasant flavors eaten—shifting from addition to subtraction. This is also why red wine often tastes better with age: because unpleasant flavors diminish, making the wine clearer and cleaner.

Photo by Sasa

Coffee Fermentation

Different biological changes occur during coffee's natural fermentation process. Yeast produces enzymes, and lactic acid bacteria break down sugars in coffee pectin. Lipids, proteins, and acids in sugars degrade and transform into alcohol acids. Coffee's aroma, color, and pH change, and the composition of coffee pectin also alters.

The core of processing methods lies in fermentation. During fermentation, different participating substances (coffee skin, pulp, pectin, microbial types, bacterial distribution), different environments (with or without water, aerobic or anaerobic, pH environment, etc.), and different drying methods and processes (container materials, natural sun drying, drying equipment, turning frequency, etc.) create different post-processing flavors and textures.

The basic coffee process is coffee cultivation → green bean processing → roasted bean roasting → coffee brewing. However, in the green bean processing stage, various processing methods are inseparable from fermentation.

We commonly see dry fermentation and wet fermentation methods, but how do the recently popular 'anaerobic processing' and 'yeast processing' methods work?

Yeast Processing Method

From any perspective, adding yeast during fermentation is a bold approach.

In 2017 in Gothenburg, Sweden, French biology PhD Camille Delebeque gave a presentation at Re;co. His company controls microorganisms during coffee fermentation to change coffee flavor, making coffee less bitter, less astringent, and sometimes even less acidic. He calls this product "Cultured coffee" or "microbial coffee."

Their approach involves selecting specific yeasts or microorganisms for so-called secondary fermentation to enhance good flavors or reduce undesirable ones. Although he didn't reveal what microorganisms he used, nor explain how his secondary fermentation works, and provided no information about coffee origins or bean varieties, his product pricing is anything but cheap—5 ounces (148g) costing $29.

El Salvador's most renowned coffee farmer Aida Batlle collaborated with American roaster Equator to test yeast's impact on flavor by adding yeast to fermentation tanks for Bourbon beans from the Buenos Aires farm in El Salvador, comparing results with traditional washed processing without yeast. In 2017, they experimented with two different yeasts and found that different yeasts produced different results. One increased sweetness, balance, and consistency, while another enhanced brightness and fruit characteristics. Yeast processing added flavors that traditional washed processing rarely achieves: sugarcane, lemon, nutmeg, and sage.

According to official information, this year's Panama Geisha Estate Geisha auction yeast processing series (ES-Y) consists of four lots and nine boxes of Geisha coffee beans with unique flavors, processed using a new "yeast fermentation method."

One of the biggest highlights of this year's auction was the addition of "yeast processing lots": fermented in fermentation tanks with special yeast for 48 hours before washing, then dried on drying beds for 4 days. The unique yeast processing batches involve adding yeast during post-processing, making the fermentation process faster and more thorough while creating special flavors.

Different red wine characteristics emerge depending on the yeast used. Compared to yeast B, yeast A shows more obvious red wine flavors, with yeast A's red wine characteristics being more refined, presenting Geisha qualities more beautifully, thus making Y-1 more expensive.

Lot ES-Y-1: Processing method: Added yeast A, fermented for 48 hours, then washed, followed by 4 days of drying on racks. Auction price: $340 per pound!

Lot ES-Y-2: Processing method: Added yeast B, fermented for 48 hours, then washed, followed by 4 days of drying on racks. Auction price: $111 per pound!

According to estate manager Rachel Peterson, this "yeast fermentation method" represents Geisha Estate's attempt at processing methods to observe how Geisha coffee beans perform after yeast-inoculated fermentation.

Processing: Fully ripe red fruits are hand-picked, undersized beans are screened out, and after water floatation selection, they are soaked in clean water. Fermentation time is approximately 48 hours with yeast added, followed by sun drying. Spread in 1-2 layers on sun-drying beds for 4 days of sun exposure, average temperature: daily 16-23°C, nightly 10-15°C, achieving completely different unique flavors!

After cupping the yeast-processed red label, we were delighted to find that this method enhanced Geisha coffee's performance in all aspects (including aroma, body, acidity, and aftertaste), and it's quite different from natural processed Geisha. Overall, it's closer to anaerobic fermentation—this processing method produces excellent Geisha in terms of aroma and flavor. It smooths out the harshness and excessive acidity of washed coffee, bringing balance and rich layers, while adding red wine-like flavors.

Geisha Coffee Bean Brand Recommendations

FrontStreet Coffee's roasted Panama Geisha Estate Red Label Geisha coffee beans offer full guarantees in both brand and quality. More importantly, they provide exceptional value—for 100 grams at only 350 yuan. Calculating at 15 grams per cup, one package makes 6 cups, with each cup costing only about 60 yuan. Compared to café prices that often exceed 100 yuan per cup, this represents a truly conscientious recommendation.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473