By Ian Griffin - Booch News and Hannah Crum - KBI
Like beer, kombucha is a fermented beverage; in fact, it is fermented tea. It has been around in one form or another for nearly 2,000 years. First brewed in China, it then spread to Japan and Russia. In the early 20th century, it became popular in Europe — following World War One, soldiers brought it back from Russia to Germany, Poland, and elsewhere.
It is a healthy and refreshing beverage full of B vitamins, organic acids, antioxidants, and trace amounts of alcohol.
Once the primary fermentation ends, many home brewers and commercial brands flavor the kombucha with fruits, herbs, or spices, allowing it to undergo secondary fermentation. This is when additional carbonation–a natural effervescence–will occur. Many brands also add CO2 to the final product for consistency and stability. Kombucha is known for its expansive flavor profiles that range from fruity to earthy to medicinal and savory.
The public and the scientific community have accepted fermented foods as functional foods. In the case of kombucha, fermentation yields not only delicious flavors but also increases antioxidant content, improving the health-promoting capacity of the tea.
There are many types of commercial kombucha. They range from pasteurized or filtered shelf-stable kombucha to 'raw' or 'authentic' natural kombucha. There is also a growing market for hard kombucha, with ABV levels up to 11%.
Natural kombucha needs to be kept refrigerated since it is biologically active. The fermentation process continues as long as bacteria and yeast have sugars on which to feed. Yeasts are temperature-sensitive, and cold temperatures keep them less active. Trace amounts of ethanol are naturally produced by the fermentation process as a preservative to prevent mold and other pathogens from feasting on the delicious sweet tea. Keeping kombucha cold is essential to ensure the quality remains consistent and compliant.
Kombucha is a rapidly growing, multi-billion-dollar, worldwide market. The Booch News Worldwide Directory lists over 650 brands in the USA and over 2,500 worldwide. The market in the USA is dominated by a few large brands with many smaller 'craft' producers.
It's become commonplace to note that the kombucha industry is where craft beer was a few decades ago. Apart from a small number of national brands, such as GTs, Health-Ade, and Humm, and a few strong regional players, such as Mother Kombucha in the Southeast, most brands are selling direct to consumer with limited distribution. The craft beer world started in a similar fashion. In the 1980s, there were only around 40 breweries. By 1993, there were 446 breweries in operation; a year later, this grew to 601. Today, there are currently around 9,000 craft beer producers in the States.
Kombucha is an option for beer brewers looking to broaden their product offerings and differentiate themselves from the competition. Brewers Association economist Bart Watson states, "21% of breweries report some production of non-beer beverage alcohol such as seltzer, mead, and hard kombucha."
As kombucha volume continues to rise and the growth rate in craft beer sales slows down, brewers are looking for new ways to grow profitably. One option to consider is producing kombucha. Kombucha shares some of the process steps of beer making, e.g., brewing, fermentation, and packaging; however, there are some significant differences, as we'll explain below.
Kombucha production also uses equipment such as stainless-steel tanks, pumps, filters, etc., from the same vendors that serve the beer market.
As we've noted, "Now thoroughly destigmatized, more bars and restaurants will include a dedicated non-alcoholic section on their beverage menus. These emerging products are expected not only to be offered as packaged goods in the on-premise, but they will take their place in the coveted draft program, especially where "local craft" is featured. Non- and low-alcohol options are a great way to increase ticket averages and responsibly upsell. This is a favorable trend customer-centric bars and restaurants will embrace."
Kombucha has attracted the attention of large brewers and soda companies. The Coca-Cola Company has an interest in Health-Ade. Pepsi invested in Kevita. Molson Coors bought Clearly Kombucha. Belgian brewer Duvel Moortgat purchased a majority stake in Jarr Kombucha and moved production from the UK to Belgium. Michel Moortgat, CEO of Duvel, said the process used to make kombucha is "very similar to that of beer," adding, "it is the result of all-natural ingredients brewed to a tasteful drink by highly passionate people."
This is also true in the case of the rapidly growing hard kombucha category. The Boston Beer Co produces Wild Ginger Blueberry Kombucha with 4% ABV, and Deschutes Brewing Co produces Humm Zinger Kombucha Radler with 4.3% ABV. Sierra Nevada produces Strainge Beast with 7% ABV.
Anheuser-Busch bought a stake in Kombrewcha in 2017 and continues to innovate. It upped its hard kombucha alcohol content from 3.2% ABV to 4.4% ABV and then hard seltzers.
"The hard kombucha segment thus far has been dominated in the off-premise by five brands: Boochcraft (32% market share), GT's Classic Synergy Kombucha (22%), JuneShine (14%), Flying Embers (10%) and Kyla (6%), according to market research firm Nielsen."
Other than in the case of sour beer production, a pure yeast culture is used in most beer fermentations. The yeast culture is chosen based on its desired flavors and process performance. In kombucha, a mixed culture is used. The yeast cells live in symbiosis with bacterial cells in a mixed culture called a SCOBY (symbiotic culture of bacteria and yeast).
A pellicle of cellulose is grown by the dominant bacteria (Acetobacter or Gluconacetobacter) and the yeasts (Brettanomyces bruxellensis and Saccharomyces species). These live in the pellicle and hang from the bottom of it. A "starter liquid" from a previously fermented kombucha, also known as "backslop," is added to the sweet tea mixture. Alternatively, a SCOBY can be procured from commercial suppliers: different SCOBYs will result in different flavor profiles in the final product.
The yeast in kombucha prefers simple sugars. If more complex sugars are used, this can lead to over-souring and off flavors. Sucrose ("table sugar"), which is made up of glucose and fructose, is ideal.
Fermentation temperature is key to the organisms' health and flavor development. Compared to lager yeasts which work best around 48 to 58 oF (9 to 14 oC), or ale yeasts which produce good results around 68 to 72 oF (20 to 22 oC), kombucha fermentations are often warmer around 75 to 85 oF (24 to 29 oC).
These warmer temperatures speed ethanol formation, which spikes early in the fermentation process. Then, when exposed to oxygen, some of the ethanol is converted into organic acids, lowering the kombucha's pH. This lower pH gives kombucha its signature tang, and it is not conducive to some of the microbial growth, including mold growth.
In addition to fostering yeast growth, oxygen exposure can drastically change the beer flavor stability. In the case of kombucha, oxygen during fermentation is important. Fermenters are open, with just a tightly woven cloth above them, which allows CO2 to escape and oxygen and microorganisms to enter. Oxygen is a vital ingredient for kombucha because it helps convert some of the ethanol produced by the yeast into various compounds, including the organic acids previously mentioned.
Microbial contamination from other non-intended microorganisms can alter the flavor of a kombucha batch. Beer's sensitivity to potential microbial spoilage from other organisms requires good cleaning and sanitation procedures. These requirements also apply to kombucha production.
Scale-up in kombucha production can be tricky. Just as adjustments in yeast pitch rate, wort oxygenation, and fermentation temperature are needed to match the desired beer flavor at different fermenter volumes, process adjustments may be required when scaling up kombucha fermentations.
To produce hard kombucha, simply add sugars or select brewers' yeasts and procced with a second round of fermentation that creates alcohol.
Just as the production of some sour beers represents a risk to the production of "regular" (i.e., non-sour beers), so it is for kombucha. For instance, the presence of Brettanomyces yeast is considered a spoilage organism for most beers (an exception being a Lambic style beer, for example) as it can cause a "barnyard" flavor. Microbial cross-contamination can quickly happen through ambient air and crevices in the tanks, hoses, seals, etc.
When it comes to distribution, most kombucha is sold in glass bottles, although cans are on the rise. Only a small percentage is sold on tap.
"We brew our kombucha and First Street beer under the same roof in our Hastings, NE facility. But we keep both products well apart. In fact, the only thing they share is the floor drain." -- Jessi Hoft, Ensign Beverage.
Every batch of kombucha, when brewed with the right ingredients and temperature conditions, will yield a culture that can be used again (similarly to a good beer fermentation yielding a good crop of yeast that can be re-pitched). SCOBYs are famous for being highly reproductive, and a sign of a good quality batch is that the SCOBY will grow when left at room temperature. The SCOBY will also expand to the size of the vessel such that the larger the tank opening, the larger the resulting SCOBY will be. This prevents contamination from external organisms by creating a "lid" (which also helps create a more anaerobic fermentation condition underneath the SCOBY).
One of the best practices for kombucha breweries is to keep some extra cultures on hand in a "SCOBY Hotel." This stock needs to be carefully maintained (e.g., with added kombucha or sweet tea) to maintain its viability. SCOBYs are more resilient than lager or ale yeasts (which lose viability more rapidly and must be stored at colder temperatures). The stored SCOBYs are like an "insurance policy" in case of microbial contamination, poor SCOBY performance, or when volume scale-up is needed.
Often SCOBY pieces or disks will be used to start a larger-sized batch but given time, the new layers can get quite large and unwieldy. They also continue to thicken if left for extended periods. It is quite heavy as it is hydrophilic and can absorb over 100x its weight in liquid! When brewing kombucha in large tanks, the vessels need to have a manway that operators can safely go into the tank and physically remove the excess culture for cleaning by pushing it out the opening.
Excess culture has a variety of uses and can be offered as compost or animal feed to local farms, used to make SCOBY-based food products (e.g., SCOBY fruit leather), or even used for beauty treatments. While SCOBYs could potentially be sold as a byproduct, most companies don't have a way to monetize it and usually give it away to anyone who will use it.
If you are serious about kombucha, you should consider joining Kombucha Brewers International (KBI), the leading industry association. KBI strives to promote, protect, and enhance the overall well-being of the industry by creating an open line of communication between brewers, consumers, and regulators while advancing our industry through advocacy, education, research, and modern legislation.
Next, check out the ecosystem of integrated products and services we offer under three primary branded platforms: MarketMyBrewery offers craft brewers a robust cloud-based environment to manage sought-after product and taproom information, optimized to attract and retain loyal consumer and trade customers; BreweryDB is the world's largest curated database of independent craft breweries, now with listings for kombucha; and The Performance Platform converges accurate product knowledge with "ounce-by-ounce" customer data to raise the human and financial performance of draft beverage programs.
Ian Griffin publishes Booch News, the premier source of industry news and a Worldwide Directory listing over 2,600 commercial brands. Hannah Crum is the co-author of the best-selling “Big Book of Kombucha” and President of Kombucha Brewers International.
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