Many Alcohol Related Questions and What Kombucha/Lactobacillius Eats

[sagedeer]

Hello, I am starting a small kombucha business and am working on ensuring the alcohol content stays below .5%. This has been difficult as it is not possible to measure alcohol content in kombucha without rather special equipment. This is because the bacteria present in kombucha eat the alcohol the yeast produce.

My plan so far is to limit the yeast populations by
A) brewing at a lower temperature (70-75 F) where yeast are less active
B) adding more oxygen to bottles to continue bacterial production that eat alcohol once bottled.
C) giving bacteria a jump start in tea by adding a grain syrup (almost pure glucose)
D) filtering large strains of yeast out of brewing batches
E) using a more vinegary starter
F) Refrigerate after secondary fementation

These ideas come from http://users.bestweb.net/~om/kombucha_balance/ under "DECREASING THE RATIO OF YEAST TO ACETOBACTER POPULATIONS."

However, reading http://www.happyherbalist.com/kombuchaandalcohol.aspx seems to indicate that pure kombucha does not actually produce alcohol, but it is the introduction/infection by lactobacillus or other bacterial/yeast strain that produces alcohol.

So I am thinking of different sugars and techniques to use that would inhibit one culture over another. So here are my questions:

1) What conditions do lactobacillus grow best in?
2) What is the most affordable source of organic glucose I could feed the kombucha bacteria (acetobacteria)?
3) What are the best ways of adding more oxygen to the kombucha prior to bottling?
4) What type of sugar does alcohol producing yeast enjoy? Fructose or glucose or?
5) I am considering using honey in my kombucha. The bacteria would eat the glucose, but does the yeast eat fructose?
6) What would happen if I almost entirely used glucose to feed the kombucha?
7) What will oxygen do to the flavor?
8) Out of all of this, would it just be better to get a 'pure' strain of kombucha and keep it in a very sterile environment?

Thank you so much for your help : )

 

[kyt]

I've read your post, but I'm going to need to be on the computer to reply. Unless someone else answers all your questions, I may be able to address most of them a little later.

posted via Home Brew mobile app

 

[sagedeer]

Thank you. I've been doing a lot of research today and found some answers... namely to 4 and 5 being that yeast eat both fructose and glucose. Perhaps in the end it seems as though no matter what with a raw product if there is a alcohol producing anaerobic bacteria/yeast, it is going to eat the sugar and convert it into alcohol at the right temperature. Would it be possible to have another bacteria/yeast that keeps the population of alcohol producing ones small? At one point I thought of some crazy idea that would inhibit the step just before ethanol production, but that seems like it would require some strange additive. Anyhow, I would enjoy hearing thoughts and ideas of decreasing the potential alcohol content.

Another question that just came to mind is what is the smallest amount of sugar people have used and still created a good tasting batch of kombucha?

 

[zipper8650]

How about brewing a standard batch and diluting it with unsweetened tea?

 

[sagedeer]

Kyt that is a possibility, but would probably create a watered-down taste. I suppose I could counterbalance that by adding more flavoring such as ginger though. People really enjoy the kombucha bite.

 

[kyt]

Kyt that is a possibility, but would probably create a watered-down taste. I suppose I could counterbalance that by adding more flavoring such as ginger though. People really enjoy the kombucha bite.

lol I didn't say that.

 

[kyt]

Per your thread title, Lactobacillus eats mostly lactose, and some strains can consume other sugars too. But kombucha should use Acetobacter, to produce acetic acid, giving it that vinegar bite.
You should try it, but I doubt adding Lactobacter to your kombucha ferment would do much of anything, with the lack of lactose. But you never know, you could train some strains to consume glucose and produce a unique KT!

Hello, I am starting a small kombucha business and am working on ensuring the alcohol content stays below .5%. This has been difficult as it is not possible to measure alcohol content in kombucha without rather special equipment. This is because the bacteria present in kombucha eat the alcohol the yeast produce.

If you're going to run a business, you need the right equipment. It'd be a tax write off as a business expense anyway. By selling a product to the public, you're going to be regulated, so you're going to need to know what the content really is, and not an approximate or you'll have to pull your product, maybe get fined, and who knows what else the ABC or BATFE would try to do.

My plan so far is to limit the yeast populations by
A) brewing at a lower temperature (70-75 F) where yeast are less active

Low 70's is in the high range for brewers ale yeast. If you want less active yeast, ferment in the lager range.

B) adding more oxygen to bottles to continue bacterial production that eat alcohol once bottled.

The yeast and bacteria will compete for the O2. I doubt adding it deliberately will produce the desired effect, but try it anyway.

C) giving bacteria a jump start in tea by adding a grain syrup (almost pure glucose)

Both the yeast and bacteria consume glucose, you'll just be feeding both. If you want to jumpstart the bacteria only, add ethanol, like vodka. I have, it works exceptionally well for producing a cloying vinegar, if that's what you're after.

D) filtering large strains of yeast out of brewing batches

This isn't going to do you a whole lot of good as the yeast are dispersed in the liquid. The ooglies at the bottom I would hope you'd strain anyway.

E) using a more vinegary starter

Just because the solution is more acidic, doesn't necessarily mean there's more or less of the yeast.
Besides, you need the yeast to make the ethanol, or you'll just end up with sweet tea that has a cellulose pancake on top.

F) Refrigerate after secondary fementation

You're going to need to do this anyway.

These ideas come from http://users.bestweb.net/~om/kombucha_balance/ under "DECREASING THE RATIO OF YEAST TO ACETOBACTER POPULATIONS."

However, reading http://www.happyherbalist.com/kombuchaandalcohol.aspx seems to indicate that pure kombucha does not actually produce alcohol, but it is the introduction/infection by lactobacillus or other bacterial/yeast strain that produces alcohol.

This statement doesn't make sense as written. There's not really such a thing as "pure kombucha" and saying it does not produce alcohol is like saying pure unicorns don't actually fart rainbows.
Unless you're making your kombucha with milk, I really doubt you have Lacto.
There's a lot of "folk knowledge" and just plain wrong information surrounding kombucha.
Things like this: "refrigeration of properly fermented kombucha mushroom tea forces the live beneficial bacteria and yeast to become inactive, and no further fermentation proceeds."
Not true, refrigeration does severely retard metabolism, but it does not stop it. There'll be more than a handful still chugging away in that refrigerated bottle.

So I am thinking of different sugars and techniques to use that would inhibit one culture over another. So here are my questions:

1) What conditions do lactobacillus grow best in?

Dairy

2) What is the most affordable source of organic glucose I could feed the kombucha bacteria (acetobacteria)?

I use Domino Cane sugar. It's cane sugar, so you can be sure it's not made from GMO sugar beets. It's also cheaper than all the weird hippie sugars and easier to find and purchase in bulk. I bought 2 cases of 4lb bags from Whole Foods during a BOGO sale. So 80lbs for, I want to say, $26-ish. And that was from Whole Foods, so you could probably find a distributor and get it cheaper. Having said that, you do get more flavor from using a less processed, albeit organic, sugar. Organic Sucanat imparts a whole lot of flavor, but what can happen is the extra minerals accumulate in subsequent batches and you could end up with a really strong molasses flavor. This happened to me because of the way I processed the finished KT.

3) What are the best ways of adding more oxygen to the kombucha prior to bottling?

"Best" is subjective. If you really really want to do this, I'd say splashing is the best way. If you want to risk product with huge amounts of injected O2, use an O2 tank and .5 micron stone. The recommended limit for brewing beer is about 30 seconds of exposure.

4) What type of sugar does alcohol producing yeast enjoy? Fructose or glucose or?

Brewers yeast typically go for glucose, and fructose, in addition to other compounds if present, like maltose in beer, but not lactose and a few others.
Sucrose is glucose+fructose.

5) I am considering using honey in my kombucha. The bacteria would eat the glucose, but does the yeast eat fructose?

Both the yeast and the bacteria consume glucose. The yeast will metabolize fructose too, I don't know if any bacterium metabolize fructose, but I imagine some might. The acetic acid is formed by oxidation of ethanol, I believe the acetobacter only use the glucose to form the pellicle.

6) What would happen if I almost entirely used glucose to feed the kombucha?

You'd probably end up with a very dry tasting KT and a good amount of pellicle formation.

7) What will oxygen do to the flavor?

After fermentation is complete? I can not notice any appreciable difference between finished KT that has been carefully harvested and bottled, and KT that was splashed into a bottling bucket. It may depend on how long the re-oxygenated KT is stored, and how much O2 was dissolved.

8) Out of all of this, would it just be better to get a 'pure' strain of kombucha and keep it in a very sterile environment?

I'm not aware of any "pure" strain. It seems to me the whole purpose of KT is a deliberate infection. This causes it to be different almost every time I make it. However, in the commercial world, customers expect consistency. So it would behoove you to learn how to isolate and propagate the strains you wish to use. Just like how a commercial brewery does it. You'd probably need to hire a microbiologist. I heard, on an episode of Brew Strong, that there is a White Labs certification course; you could look into that.

Thank you so much for your help : )

Whew! You're going to send me some for typing all this, yes?

 

[sagedeer]

Whew! Thanks for all the answers. Sorry some of them were based on unfactual article knowledge. I'll need to get you a bottle once we're all certified


Follow up question:

What is a semi-affordable method of accurate alcohol testing, or would just sending it to a lab be the cheapest? I read several methods but all seemed rather technical.

 

[kyt]

Whew! Thanks for all the answers. Sorry some of them were based on unfactual article knowledge. I'll need to get you a bottle once we're all certified


Follow up question:

What is a semi-affordable method of accurate alcohol testing, or would just sending it to a lab be the cheapest? I read several methods but all seemed rather technical.

You could distill it.
Other than that, I would call whoever regulates kombucha. FDA? ABC? BATFE?
Find your local office and ask them how they would prefer your determin ABV/ABW. If you have a local microbrewery, you could probably stop in there and ask the lab tech or brewmaster.

 

[sagedeer]

Gotcha. One more silly question then I'll be done with it all : )

Since alcohol is less dense than water, wouldn't you hypothetically be able to allow the liquids to settle, and then remove the top 10% of the solution to rid of the alcohol?

 

[snarf]

If that were possible it would make distilling really easy

So no, that doesn't work, because water and alcohol are miscible: they mix in all proportions, forming a homogeneous solution.

 

[kyt]

Gotcha. One more silly question then I'll be done with it all : )

Since alcohol is less dense than water, wouldn't you hypothetically be able to allow the liquids to settle, and then remove the top 10% of the solution to rid of the alcohol?

No because it is in suspension. It's not like vodka in orange juice lol
However, because ethanol has a lower boiling point than water, you can heat it to evaporate the ethanol. Looks like 78°C will do it, it'll also pasteurize your kombucha. The length of time depends on how much you started off with.
Or you let the acetobacter oxidize it.

Or, you could use a different strain of yeast, that produces less alcohol. There are a few, but I can't think of any names at the moment. Coffee cup is still pretty full.

I know this is for beer, but read over it anyway. You may find some helpful bits.
http://byo.com/low-alcohol-brewing/item/263-brew-a-great-non-alcoholic-beer

 

[bsb]

Regarding lactobacillus. I know Wikipedia sometimes has errors but it's a good place to start further research.

Some Lactobacillus species are used for the production of yogurt, cheese, sauerkraut, pickles, beer, wine, cider, kimchi, cocoa, and other fermented foods, as well as animal feeds, such as silage. Sourdough bread is made using a "starter culture," which is a symbiotic culture of yeast and lactic acid bacteria growing in a water and flour medium. The bacteria metabolize sugars into lactic acid, which lowers the pH of their environment, creating a signature "sourness" associated with yogurt, sauerkraut, etc.

In many traditional pickling processes, vegetables are submerged in brine, and salt-tolerant lactobacillus species feed on natural sugars found in the vegetables. The resulting mix of salt and lactic acid is a hostile environment for other microbes, such as fungi, and the vegetables are thus preserved -- remaining edible for long periods.

Maybe the question should first be, what strain of lactobacillus are we talking about?

I found a beer brewer who managed to brew beer with no yeast, but only a particular strain of this bacteria, which feeds off maltose, maltotriose, and raffinose: http://www.themadfermentationist.com/2012/06/100-lactobacillus-berliner-weisse.html


Here's another website about the lacto-fermentation of vegetables:

Lacto-fermentation is the process that produces traditional dill pickles, kimchi and real sauerkraut. It takes nothing more than salt, vegetables and water - no canning, no fancy equipment.

This simple process works because of the lucky fact that bacteria that could be harmful to us can't tolerate much salt, but there are healthy bacteria (think yogurt) that can. I think of them as the bad guys vs. the good guys. Lacto-fermentation wipes out the bad guys in its first stage, then lets the good guys get to work during stage two.

http://foodpreservation.about.com/od/Fermenting/a/Lacto-Fermentation-How-It-Works.htm


The interaction between all of these different kinds of bacteria in kombucha interests me too. It doesn't seem to be a constant process from one scoby/batch of kombucha to another, so that complicates things, but there must be certain commonalities between them all.

 

[BoochBrewer]

Hello, I am starting a small kombucha business and am working on ensuring the alcohol content stays below .5%. This has been difficult as it is not possible to measure alcohol content in kombucha without rather special equipment. This is because the bacteria present in kombucha eat the alcohol the yeast produce.

My plan so far is to limit the yeast populations by
A) brewing at a lower temperature (70-75 F) where yeast are less active
B) adding more oxygen to bottles to continue bacterial production that eat alcohol once bottled.
C) giving bacteria a jump start in tea by adding a grain syrup (almost pure glucose)
D) filtering large strains of yeast out of brewing batches
E) using a more vinegary starter
F) Refrigerate after secondary fementation

These ideas come from http://users.bestweb.net/~om/kombucha_balance/ under "DECREASING THE RATIO OF YEAST TO ACETOBACTER POPULATIONS."

However, reading http://www.happyherbalist.com/kombuchaandalcohol.aspx seems to indicate that pure kombucha does not actually produce alcohol, but it is the introduction/infection by lactobacillus or other bacterial/yeast strain that produces alcohol.

So I am thinking of different sugars and techniques to use that would inhibit one culture over another. So here are my questions:

1) What conditions do lactobacillus grow best in?
2) What is the most affordable source of organic glucose I could feed the kombucha bacteria (acetobacteria)?
3) What are the best ways of adding more oxygen to the kombucha prior to bottling?
4) What type of sugar does alcohol producing yeast enjoy? Fructose or glucose or?
5) I am considering using honey in my kombucha. The bacteria would eat the glucose, but does the yeast eat fructose?
6) What would happen if I almost entirely used glucose to feed the kombucha?
7) What will oxygen do to the flavor?
8) Out of all of this, would it just be better to get a 'pure' strain of kombucha and keep it in a very sterile environment?

Thank you so much for your help : )

I don’t know if you still use this forum, but I’d love to know if you figured out how to lower/control the ABV. I’m on the same mission!