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Sebastien Bureau on The Science of Kombucha

Sebastien Bureau on The Science of Kombucha

Are you interested in brewing Kombucha but you don’t know where to start? I had the pleasure of speaking with Sebastien Bureau. Sebastien runs a Kombucha brewing masterclass (15% off with promo code GURU2020)

to help you start that journey today! Read on to learn about store-bought vs homemade kombucha, the best kombucha ingredients to add,benefits of longer ferments vs shorter ferments and much more.

How Did You Start Your Fermentation Journey?

I like to cook and that brought me to fermentation. I am a food scientist, I have a background in molecular biology of plants and chemistry, and my favorite thing is making mistakes. I love jumping into scary things, failing a dozen times, then finally getting it right. Right now, I am on a sourdough adventure. Fermenting it in different ways and understanding it. I know that I won’t get anything satisfactory for me for at least a couple of months.

I consider myself a completely unmanageable guy. I started my business knowing what I wanted to do and knowing that I didn't want to work for anyone else. I am a fermenter and I consider myself a guy who likes to make food and figured out a way to make a living from it without working evenings or weekends!

Sourdough and Other Ferments

I am all about using the tools that you have and not trying to impress anyone with fancy equipment. There are many impressive things that you can do and in the end, it's a lot more impressive than anything that would have been made in a lab.

There was a man who baked a sourdough loaf with yeast samples from 4,500 years ago. The article is HERE. This is almost like stepping back in time to what these people would have been consuming back then... It is like some sort of connection to the past. -Kriben Govender

There are a lot of gimmicks but it is all about the story. Whether it makes a good product, in the end, is irrelevant. We like to build our own stories with our products. We can have honey that is made by a small producer and it tastes the same as honey made from a large producer who is not organic, but we attribute a lot more value to the artisanally produced one because of the process. Food is a type of art. If you have an interesting process and history it attributes to the product. 

There is also a brewery in Quebec who did the same thing with their beer. They went to an old brewery from hundreds of years ago and tried to get some yeast there. They isolated the best yeast and then they made beer from it. It is a great story, but the techniques used today would not have been the techniques used back then so it is funny that we are using techniques to extract what it would have done.

There was another interesting study that came out on sourdough and they were doing metagenomic analysis of the sourdough as they were being made. The study concluded that a lot of the bacteria were actually from the hands of the baker. That is pretty fascinating. You have some of the microbes coming from the flour but a big portion are coming from the baker's hands. This is interesting because it's almost like the baker is putting his own genome into the flour which then elicits the flavor and the texture of the sourdough. -Kriben Govender

One of my favorite questions in my classes is “What about sanitation?” I always say “These are ancient techniques, the less you clean your hands the better it will taste.” 

I recall a microbiology class in university , when they get you to do an agar plate of your hand and then watch the different microbes grow. And isn’t it interesting how much the paradigm has shifted from microbes being a dirty word and something that could be harmful and kill you to now microbes almost becoming little heroes. Modern science is starting to understand that most of them are actually good for us. -Kriben Govender

Even the bad microbes, if you just have a few of them, they will help your immune system. They all want to grow and have their moment. We consider them bad because we put the spin on it. Eliminating them is oftentimes worse!

We did a great interview with Dr. Jason Hawrelak and he said that in the context of all microbes, there really isn’t such a thing as good and bad. It's just humans putting our spin on microbes. He was talking about this concept of an apex predator. A lot of these microbes in our gut, for example, Blastocystis which is a common parasite, is what we call an apex predator. In an ecosystem it is like a rainforest, these types of parasites help keep things in balance. It is the same thing with candida. Candida yeast digests a lot of the heavy metals, break them down, and help the body to get rid of them. Even though there are negative connotations with some of these microbes, there is a purpose for them. All of them in small levels are very important in the body. But when they are overgrown that is when they may become an issue. There is often a downstream impact when you take out the apex predator and perhaps some of the other flora that we are suppressing and under control are allowed to become a bit more dominant. The microbiome is a young field of research and we need to be mindful of the things we are doing in that space and what conclusions we are drawing from it. -Kriben Govender

We also make Tempeh. I grow it on rice in a mason jar and make it very sterile. Growing something like tempeh in the fermentation world is instant gratification. In 24 hours it was grains then it goes to a solid white block that you can tell all your friends about. It is a satisfying type of fermentation as well.


Medicinal Mushrooms

I have had an interest in mushrooms from the start of my fermentation journey. They are the opposite of the apex predator, they are the lowest one on the chain. They have the most equipment to break down the things that compose our world. They are one of the only things that can break down plastic! Mushrooms are really good at picking up the pieces and they are the bottom feeders of the microenvironment. When I tell people I have been mushroom picking for 10 years and they say isn't that dangerous? And yes it is but the first thing you should do is learn the bad ones. You can identify those very well and then you can learn the good ones.

Mushrooms are very interesting, you get the spores, put them in the grain, and then weeks later you have these giant mushrooms growing all over the place that pop up overnight. It's magical. I read a lot about mushrooms and how they can help save the world. For me, mushrooms are a rarity. When you go into the forest and get rare mushrooms, it is a great feeling. 

There is the culinary aspect and the medicinal aspect. We are lucky in Quebec because we have reishi, chaga, and turkey tail. All of these medicinal mushrooms are great. You can always see how healthy a forest is by the number of mushrooms that it has:

If you walk into a forest that was cut 5 years ago you are going to get a certain type of mushroom.

If you go around buildings that have just been built you will get different kinds of mushrooms.

If you go to older forests you will get different mushrooms as well.

It depends on the environment! Mushrooms are fun, delicious, and you can also use the medicinal aspects for general health. It is also a great excuse to go into the forest and not just be aimless.

In Australia, the mushroom season picks up in the fall and I had no idea about picking them. We just knew that white, the death cap, or bright red ones are the types we should stay away from. But we observed the different species and it was incredible. I didn't pick any because we didn't know what we were doing exactly but it was more spending time in nature and getting a feeling for what is out there. -Kriben Govender

In France, you can go to the pharmacy and the pharmacist is trained to identify mushrooms. You can also go to mushroom shops or facebook groups and people will help you out with it. Sometimes there may be a really big patch of mushrooms and you're wondering if they are edible, so you can pick them and identify them later because you cannot get sick just from touching them. There are also apps you can use as well!

Mushrooms are great for:

-The health aspect

-The food aspect

-The whole transformation aspect of it, you can make solid blocks to be used as sculpting material.

As an individual that was looking for tools to transform my environment through fermentation, I found that mushrooms are a very interesting avenue for that. Especially since you can see them grow as well: you have a jar, you inoculate it, nothing happens, and in a week there is a little white patch and everything grows, and then you have mushrooms. 

Mushrooms are like the informational highway for ecosystems. For example, mycorrhizal fungi is from old rainforests. It spreads everywhere and it connects the whole ecosystem together. It keeps the whole ecosystem healthy. There are a lot of parallels in that and also in the ecosystem in our bodies. The impact of the mold and fungi and the production of enzymes in our bodies. Tempeh and koji are rich in these enzymes as well. -Kriben Govender

They say that the biggest organism in the world is a mushroom in the bible belt in the USA. There is a lot of complexity to it and something that is feared and unexplored. People think “well I am not going to eat mold…” But if you eat cheese the mold is what made it, so maybe mold isn't that bad. There is this overlooked aspect of how good mold is. There is a whole side to fermentation that deals with mold and it can be one of the most powerful tools for fermentation as well. For making enzymes, antibiotics, or other sorts of things. All of our best antibiotics are made from mold.

We have to thank the microbe world for our antibiotics. The little heroes for producing things that keep us well. Also, using these molds to break down the proteins into very interesting flavors. If you think about a soybean by itself it is so bland but then you add some koji to that and all those proteins get broken down into amino acids and glutamate that lend itself to this umami, meatiness flavor. As a tool this is fascinating. You can also make Shio Koji. It is a salty koji rice and you blend it with water and let it ferment for a week. It's a rice slurry that is salty but because you allowed the mold to be activated they start to chop down the rice into smaller pieces. Then there are active enzymes and you can smear that onto a piece of steak and leave it for a couple of hours. Then you get all of these umami notes coming out plus tenderising the meat. -Kriben Govender

cured meat

Aging Meat

I explored a few meat aging techniques as well. The first time I made these meats, I did not eat them but the enzymes came from mold. They are really powerful. They can break down your steak, they can take your proteins and break them apart. I have some prosciutto growing in my lab right now and they started growing mold. Just a little bit of white mold and it will start to develop a cheesy flavor and will help make it more tender, faster. It is a rare sight but that is when you know it is going to be very good.

That is the beauty of the culinary aspect of food science. The two of us have been trained in the science behind it but then we still resonate with the creativity and you look at these different molds, bacteria, and techniques. It is a tool to create. Even though we are both analytic in our minds being scientists, the creativity in me is bursting to come out. I want to experiment with all of these palettes that I have with different bacteria, yeast, or techniques. That is what I love about food and the science aspect of it. Sometimes it's going to be terrible other times you are going to nail something that tastes amazing and then you learn something so valuable.-Kriben Govender

How Did You Get Interested in Kombucha?

I was studying molecular biology and I felt that the technology was there to do whatever I wanted to but not safely. I told myself to go towards microbiology and fermentation. I was learning all of these ferments and one of my friends from high school told me that he started making this thing called kombucha. I went to help him and it was just 200 litre vats that tasted amazing. I thought “ I don't know if I should be eating this but I'm going to do it anyway.” I was working for free for 2 months because I loved it that much.

To be successful at a Kombucha business you have to teach people how to make Kombucha. The best way to introduce people to Kombucha is to invite them in and show them how to do it, give them a scoby, have them do it, and share it with all of their friends. A huge clash with food over the past 50 years has been, “don’t do anything at home you are going to kill yourself.” But with fermentation, you can invite people back in to create these foods for themselves again. 

There is also the gut health aspect of it. You have people coming in saying they used to have a health issue and now that they drink kombucha, they have no symptoms. That line between medicine and food is a line that kombucha has ridden for a long time. Because it is made with tea and you can put a lot of different botanicals in it. Drinking kombucha makes you feel better than drinking a flat soft drink when you are sick. The reality is that kombucha is made by real people with organic ingredients and all of this is the perfect storm for great food!


What Are The Things From A Scientific Perspective That Could Be Beneficial in Kombucha?

I think that kombucha has the same effects as a probiotic.  The organisms in kombucha do have the same role as a probiotic and it will have a similar effect. The nature of kombucha being wild and artisanal, there are a ton of different types of kombucha. Even though there is a central core that is acetobacter, those compose about 50% of the organisms in kombucha. Together, all of these microorganisms that are happy and active (since kombucha is an active fermentation), contributes to gut health and a ton of different things that probiotics give you. 

The benefits depend on how long you ferment it for, but the microorganisms that are in kombucha have huge health benefits. There are two main fermentation durations:

A short fermentation: 7 days at a high temperature. It will have a lot more yeast (stimulating digestion), more alcohol, a short fermentation kombucha with high sugar, is good to stimulate digestion and speed up things. It will have higher B vitamins. This is your peak in terms of the number of microorganisms.

A long fermentation: 30-45 days it is more of a vinegar. You will have a lot less yeast and more bacteria. Bacteria may have less of an effect on health. 

Also, in terms of bacteria, there is not much lactobacillus in Kombucha. If there is, it is in the very beginning and it is from your hands. If you want a probiotic kombucha, don't wash your hands, ferment it for 24 hours and you will have a higher lactobacillus kombucha! 

The Chemical Side of Kombucha and the Benefits

The most obvious chemical component in Kombucha is the acetic acid, the organic acids (mostly acetic and gluconic.) Acetic is the one we are most familiar with. This is similar to Apple Cider Vinegar. It helps with:



-Regulation of sugar

This is what is easily quantifiable as the health benefits of Kombucha. There are also the plants that you put in there. There is a process called deglycosylation where a plant molecule that is not quite active yet becomes active in the fermentation. It becomes more bioavailable (you can absorb it better). In any given infusion you will have a certain percentage of:

Molecules that are active

Molecules that are not active

Kombucha fermentation will make it so instead of having 30% of the molecules that could be good for health you will have 40%-70% of them. That is why long term fermentation is good because as the fermentation goes on more of these molecules get eaten up. For Example:

There are antioxidants, one is catechin, and one of the most bioavailable forms of it is rutin. Rutin is something that becomes more active as the fermentation goes on. In a healthy gut, you can make it bioavailable but it's better to have it “prechewed” for you. And that is what fermentation does with a lot of plant molecules. Cannabis is legal in Canada so if you made a cannabis kombucha and you let it ferment long enough then you'll know how strong it gets!


What Should We Add To Our Kombucha?

Let's say you have a kombucha that is already fermented. Then you see that your rose bush is doing good and you decide that you are going to throw in a couple of roses in there and let it sit. You get this huge explosion of flavors and aromas overnight. If you put strawberries in kombucha, that taste will die down in a few days. The kombucha eats all of the flavors. Fruit tends to not have the flavors come out as much. They will slowly die down and with herbs, they will get stronger. A few of my favorites are:



-Celery (this addition is delicious)

-Turmeric pepper mix if you want a strong combination

You can experiment with different flavors. You have this wonderful kombucha base that lends itself to making a lot of these medicinal herbs and spices more bioavailable. But aside from that, just have fun experimenting with flavor combinations and fruit combinations and see what you can come up with. Then you might make a little magic elixir that you can share with your family.-Kriben Govender

Making healthy food is one part of it but feeling connected to your environment is another part. Being connected to your garden and becoming empowered by making your own products. I'd say that it contributes to your health just as much as drinking the kombucha. If you live in the city and all you can grow is rosemary and basil that is great for kombucha. You can make it that will last you a few months!

Commercial Kombucha vs Homemade Kombucha?

Commercial Kombucha:

It is great and it is eating up the soft drink market. So instead of someone eating something with:



-90g per litre of sugar

They are drinking something that:

-Tastes amazing

-Low in sugar

-Made with plants

-Might be local

They make it accessible to you as a person who doesn't have time to drive to the other side of town and get it from a small artisanal brewer. You can go to your local store and get whatever and it becomes a habit. You can start off with something normal and explore the market from there. Commercial kombucha is great, it is healthy and it is a health product. Kombucha companies put a big emphasis on health. They are low sugar and sometimes they even add probiotics which makes it a better product. It’s a nice entry in the world of kombucha and if you want to stay there that is fine too.

Homebrewed Kombucha:

It is very empowering. People will usually go for a higher sugar content BUT it will be less than a soft drink (just more than commercial kombucha.) Sweeter is easier to get it right. In terms of getting a kombucha buzz, well that kombucha buzz is alcohol linked. If you have a 4 litre jar and you are putting 7% sugar and its tasting really good and fizzy in 4 days then you are probably at 2-3% alcohol. It makes you feel good.

You can also put a lot more stuff in your homemade kombucha. You can see many different options HERE! There is a cost factor in store-bought kombucha, it needs to work. You can't put manuka honey in a kombucha that you are going to sell on the shelves because it is going to cost upwards of 10 dollars. When you are home you can put the honey in yours and it will still cost you less than what you would buy it for at the store. You can use super high-quality ingredients. You can also have this kombucha that is really fizzy and you can make it exactly how you want it. From a health standpoint, both are great but with homemade you can control what goes into it without regulations. 

It is just giving people an option away from soft drinks. It is a great gateway into the world of fermentation. Kombucha is the one that has the most mainstream adoption out of any at the moment. It is a good entry for people to explore kombucha then they may explore sauerkraut, water kefir, milk kefir, tempeh, and natto. All of these beautiful other fermented foods.-Kriben Govender

fermented foods

If There Was One Thing You Could Do For Your Gut Health, What Would It Be?

Stay away from processed foods! It seems complicated because it is what is being offered to us. But if you are eating these you are feeding the most vicious microorganisms and you are not giving a chance to the ones that are better at opening locks. Eating things that are less processed will give you much better gut biodiversity. You absorb things more slowly and your gut rewards you for it.  And of course, as a kombucha guy, I would say eat more fermented foods! 

As food scientists, both of us have been at many food manufacturing sites and have been on many projects involved in processed foods. I felt like crap for years, I was 14 kilos heavier than I am now. When you work in that industry you get access to all of these samples. I lived off of processed foods because I was in that industry and I felt miserable and looked miserable.-Kriben Govender 

Make sure to implement fermented foods into your diet, start your home-brewing kombucha adventure, and reap the benefits. Join our facebook group for tips & tricks and to share your fermented food’s journey with us! Share this with a friend that would benefit from this information.

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One thought on “Sebastien Bureau on The Science of Kombucha

  1. avatar Cherilyn Berry says:

    At what point in the home brew process should you add herbs? I’m thinking the second ferment…

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