Kombucha: fermented tea 红茶菌

About a month ago, I visited my parents in California. I had a wonderful time with them – we stayed in, ate homestyle Chinese food, and just chatted. For most of my life, my parents were (and still are) the best teachers. I remember distinctly struggling through AP Physics, angrily scratching out free body diagrams because it just didn’t work. My sister and I sat at the table with our papers, calculators, and pencils, and my dad dragged out a white board and began to very patiently explain what it all meant. The textbooks, the teacher’s lectures – none of it did it for me. But my dad’s explanations and live demonstrations somehow perfectly illustrated the concepts of physics. Perhaps it was the focus my dad had on the concepts versus the minute details. I don’t know – but my dad is the best teacher. Anyways, but in the past few years I’ve been able to teach him some things – history of architecture, more Western cuisines, harp technique, etc… and it’s always a privilege to have this in depth conversation where we’re exploring different topics. When I went home last month, I was so eager to talk to him about my newest obsession, fermentation. I’m sure you know where this story is headed, especially if you read the Life and Thyme article I wrote on fermentation and kombucha – my dad’s an EXPERT in fermentation!!!! I was really excited and started describing this cool but at-the-surface gross drink I was brewing, and he was like, Isn’t this hong cha jun?

Apparently, this is something he made with his entire neighborhood during the hot, humid summers in Shanghai. It was a ritual that the community did together – large batches of kombucha would be made, and cold, refreshing kombucha could be distributed to everyone. I knew that kombucha wasn’t a new thing – not by any means. But I think my dad making it when he was a teenager truly underscored the presence of making kombucha through history. You can read my article on the fermentation community in Boston, plus a recipe for blackberry lavender kombucha ice cream float (YUP) here.

This post will be all about kombucha. The drink, the method, and the variations you can use. It can be an intimidating process, but once you get the hang of it and understand the parts of it and why, then you’ll realize that kombucha is actually very intuitive. I have a continuous brew going and have already given out many SCOBY babies for future brews. If you’re in Boston and are interested in brewing kombucha, let me know. I can get a SCOBY baby to you :).

If you’ve been following me on Instagram, you’ll know that I’ve been playing with this gooey looking disk I call a SCOBY, which stands for symbiotic culture of bacteria and yeast. It’s been my recent pet project (literally, the SCOBY is like a pet) and I can’t stop drinking and playing around with kombucha. It’s a wonderful, natural process that produces a refreshingly tangy drink, and the flavor combinations are endless. I’ve been quite obsessed with fermentation lately: my first project was baechoo kimchi, and that was fun to learn about and make. Kombucha is my second one. My third? probably sichuan fermented long beans – actually, my spiced water is now aging nicely in the crock! It’ll be 3 weeks until the final product, but I know it’ll be a good one :).

My first brush with fermentation actually came through a college course on biochemistry, when I had little to no interest in food. It was very mechanism based and we spent a lot of time going over metabolism. Fermentation is a metabolic process. We learned about anaerobic fermentation on a molecular level and was forced to memorize not only the byproducts and end-products  but also the entire pathway. I hardly remember it now, but learning about the fermentation process to make kombucha reminded me strongly of what I learned in biochemistry. It can be summed up as a metabolic process that occurs on a microbial level, through which bacteria or yeast consumes carbohydrates, producing organic byproducts that can be acidic, gaseous, or alcoholic. In kombucha, you get all three. Fermentation in kombucha specifically happens first aerobically, producing acids to get the signature tangy, sharp taste. Then, the resulting brew can be bottled where it will undergo a second fermentation -this time anaerobic – to build up carbon dioxide, obtaining the natural fizz often associated with kombucha. The second fermentation is where you can play with more flavors – fruits, flowers, spices, herbs – whatever you want to add in. The article I wrote for Life and Thyme provided a recipe for blackberry lavender kombucha, and it was lovely. I’ve since used many other types of tea and flavorings.

I’ve thought about how I wanted to present this information, and I think by component might be best, so we’ll start with the SCOBY.

SCOBY

• The SCOBY is the mother. This is the culture of bacteria and yeast that will ferment your sugar and tea. You can get the dehydrated online, but I’d recommend finding someone in your community that can gift you with one. That way you’d have not only the SCOBY but also the starter kombucha tea.
• SCOBY will grow. A healthy SCOBY will grow a “baby” at the top of the brew to the exact fit of the vessel. As you can see in the photos, my small, tiny SCOBY from a mason jar soon grew a “baby” that fit the mouth of my wide fermentation crock. This should happen. Sometimes you will find stringy brown substance clinging to your baby, but that is normal – it is just the natural byproduct yeast. You can strain this out when the time comes. It’s OK if your SCOBY doesn’t float to the top – it can be sideways, tilted, or sink to the bottom. The new “baby” should form at the top of the liquid, but don’t be alarmed if it doesn’t. It will start to form layers. You can literally peel the different layers of SCOBY if you want and grow them in separate mason jars to give away. Culture sharing, after all. You should not see any mold or dry fuzzy patches. You should not see any wiggling movements, which may be fruit fly larvae.

STARTER KOMBUCHA

• Starter kombucha can help bring the acidity of the mixture to a more appropriate level in order for a healthy SCOBY to thrive as well as to keep unwanted bacterias out. As the fermentation process proceeds, the overall acidity of the brew will increase. Sugar is consumed over time with acid as the byproduct, so your brew will increasingly become less sweet and more tangy. It will be up to you if you prefer a more tangy brew or a sweeter one. I start to taste the brew after 6 days to see the level of tanginess.
• About 10% of your brew should be starter tea.
• If you don’t have access to starter kombucha you can use white distilled vinegar, which I used for my first batch actually, since I didn’t have enough starter tea.

TEA

• I used Chinese black tea, oolong, pu-er, and jasmine green tea with great success. I actually did experiment with a batch using matcha, a powdered green tea, but it didn’t taste good. For all of these teas, the SCOBY babies formed were healthy and thriving. I do not recommend using oiled teas such as earl gray, but I have heard that these work. The important thing about the tea used is that it be of the actual tea leaf from the plant Camellia sinensis. A lot of the teas – black tea, green tea, white tea, etc – are all variations of this plant: picked at different times of the cycle, grown in shade or not shade, fermented, oxidized, etc – if you’ve ever been to a tea room in Asia you’ll know just how varied teas can be. This website is a fantastic resource for different types of teas and notes associated with them. I prefer a stronger brew of tea, so I used loose leaf tea, although tea bags will work as well.
• The water you use to brew the tea should be pure water. I know people who have done it with normal tap water with no problems, but I just bought a gallon of pure water just in case.
• Add the SCOBY only after the tea leaves (and any metal strainers) are removed and the brew has cooled to room temperature. A too warm environment can kill off your SCOBY. One trick I use is to brew a small, concentrated batch of about 3 cups of tea, then dilute it with the rest of the water at room temperature. This can bring the temperature down rapidly. I then it it steep, covered for at least 15 minutes, and then until room temperature.

SWEETENER

• Cane sugar is used, but apparently what is known as “jun” is honey-sweetened kombucha. I was at first confused because in Chinese, kombucha is referred to as “hong cha jun”, 红茶菌， which literally translates to black tea mushroom. I assumed jun was just kombucha. I’ll have to do more research into this – much gets lost in translation, after all. I’d like to try using honey one day.

VESSEL 

• Choose a wide mouthed vessel made of glass, ceramic (no lead), or stainless steel. Plastic is not recommended due to some unsavory tastes, but I’ve not used it myself. I use a ceramic fermentation crock gifted to me by Jeremy. It has a beautifully wide mouth perfect for kombucha. The initial fermentation requires constant aeration, so maximum surface area to volume ratio would be optimal. Air is a friend, so let’s try to give the SCOBY maximum surface area.
• The cover should be a tightly woven, porous surface. I use many layers of cheesecloth, but I’ve heard from others that it can still allow fruit flies to get in. While I’ve never had a problem using cheesecloth, this does worry me so I’ve since switched to using simple tea towels as a cover. I’d recommend being on the safe side and using a tighter weaved cloth.
• Always, always sanitize everything with a NON antibiotic soap and hot water. You can also rinse everything with white distilled vinegar.
• Store away from direct sunlight.

SECOND FERMENTATION 

• This is your blank canvas. You’ve chosen your tea, and now you can play with the flavors.
• The sweeter the additions, the faster the ferment, which means faster build up of carbonation. To prevent any possibilities of explosion, let the kombucha “burp” once a day, or every other day. I’ve only heard of kombucha explosion once -but she let it go in the basement for 11 days without burping. I let this go for about 5 days, with burping and I got some great carbonation. In fact, I open the resulting kombucha over the sink sometimes, because it will spew out like opening a bottle of champagne.
• Don’t use a metal lid, because the acidic brew will react with metal. I recommend flip-top brewing bottles.
• Some great combinations
  • blackberry lavender
  • peach rose
  • peach with oolong tea
  • ginger carrot
  • pineapple ginger (this is my favorite) 
  • apple cinnamon
  • plum, by itself
  • strawberry basil

NOTES

• When brewing a new batch of kombucha, I always reserve a “safety” SCOBY – you should be able to easily peel layers away. I use one for my big brew, and another with some fresh sweet tea in a smaller jar, just in case

RECIPE: KOMBUCHA

Ingredients
3 + 7 cups pure water, separated
3 tablespoons loose leaf tea (or equivalent in tea bags, about 7-8 bags)
1 cup sugar
1 cup starter kombucha or distilled white vinegar
SCOBY

Sample 2nd fermentation:
1/3 cup chopped peaches
1 tbsp dried rose 

 

1| Prepare sweet tea: Bring 3 cups of water to a boil. Add 1 cup sugar and stir until dissolved. Turn off heat. Place tea strainer in and let steep for 5 minutes. Then, add in the remaining pure water and let cool to room temperature. Leave tea leaves in as the sweet tea cools.
2| Remove strainer and add sweet tea to fermentation vessel.
3| With clean hands, gently slide SCOBY to the top of the crock. If it sinks, don’t worry about it.
4| Cover jar with layers of porous material and rubber band it tightly.
5| Place brew in a warm corner away from direct light and away from other fermentation vessels.
6| Ferment for 7-10 days. At day 7, taste the brew. The longer the ferment, the more tangy your brew will taste. Kombucha should be tart and sweet.
7| Second ferment: Pour brew into glass jars with airtight lids and seal with secondary flavoring for another 2-5 days. Let burp once a day to prevent drastic pressure buildup.
8| When kombucha is flavored and fizzy enough, transfer to the fridge. Serve after straining.

And.. puppy photobomb!!!