maltodextrin / crystal malt in kombucha

[Owly055]

With one foot in the beer world, and one in the kombucha world, it is inevitable that I would carry the technology of one to the other and vice versa............... I've of course been doing this.

I've blended fermenting beer and fermenting kombucha, and fermented them together with good results........ my first such experiment. The "beer" wasn't hopped, just dry malt extract and yeast. I set up a continuous fermenter of kombucha, and as I drew a liter out and bottled it, I replaced it with a liter of fermenting beer....... I did this every 4 days until I had merged the two. The result was interesting and very drinkable.

I've also replaced sugar with malt extract in my primary fermentation.............. it doesn't work as it produces an immense amount of sediment that floats around, and the yeast action overwhelms the bacteria which ultimately quits working and dies out.

My favorite trick is to use a rich fermenting malt syrup with ginger in a small percentage to the bottles at secondary. I use 1/4 cup per liter usually. This works nicely, but has to be controlled carefully or the result can get to sour quickly in the bottles. It also creates a LOT of CO2, and bottles MUST be safetied so they can vent. In a crown cap bottle it would produce the classic bottle bomb!

Now I'm about to embark on a refinement, using the desired brix targets (percent sugar by weight), I'm going to start using a large percentage of crystal malt in my bottling syrup to regulate how much will be fermented out. I'm also planning to buy some maltodextrin powder and use it in my primary as a percentage of the sugar in the sweet tea. My original brix with one cup of sugar to a gallon of sweet tea is 5.2 (%), my target is around 3 at the end of primary. My target is between 3 and 4 out of the bottle into the glass.

The idea here is that I can control the process to achieve the desired result using unfermentable sugars. This is probably exactly how GTs managed to control their product, along with selecting their yeasts carefully.

H.W.

 

[calebhanson]

This is great! Are you brewing a variation on a beer, or is it more of an ad-hoc recipe? We've done a few variations, and it's tricky to select a tea and a beer recipe that complement each other. And let us know how the maltodextrin works out, we found when we tried it that the fermentation became kind of unstable and also produced some strange flavors.

We've done a lot of experimentation in this area, and I don't think you'll ever be able to get to the point of a shelf-stable bottle of kombucha / kombucha beer. The best thing to do if you're going to bottle condition is to keep popping bottles and trying your batch until you get to the right balance of sugar, acid and alcohol, then arrest the fermentation by putting the batch in the fridge. Otherwise, you'll end up with bottle bombs or undrinkable, way overfermented, super-acidic, super-carbonated drain cleaner. :cross:

Best of luck, keep us posted!

 

[Owly055]

This is great! Are you brewing a variation on a beer, or is it more of an ad-hoc recipe? We've done a few variations, and it's tricky to select a tea and a beer recipe that complement each other. And let us know how the maltodextrin works out, we found when we tried it that the fermentation became kind of unstable and also produced some strange flavors.

We've done a lot of experimentation in this area, and I don't think you'll ever be able to get to the point of a shelf-stable bottle of kombucha / kombucha beer. The best thing to do if you're going to bottle condition is to keep popping bottles and trying your batch until you get to the right balance of sugar, acid and alcohol, then arrest the fermentation by putting the batch in the fridge. Otherwise, you'll end up with bottle bombs or undrinkable, way overfermented, super-acidic, super-carbonated drain cleaner. :cross:

Best of luck, keep us posted!

This is exactly the reason I was looking at maltodextrin.............. Unfortunately I set that project aside, as maltodextrin is very low on sweetness. I don't personally think there is such a thing as "shelf stable" kombucha.... You can probably control the yeast aspect of the fermentation, but there are several ferments going at once. The best solution would be to use a 1.7 gallon corny keg for secondary so you could retain the carbonation of the bottle conditioning, while being able to sample easily.
All my experimentation is during secondary (bottle conditioning). I have made some nicely beery kombuchas with a nice head and malty flavor that way........but they are short life products.

H.W.

 

[snarf]

I don't personally think there is such a thing as "shelf stable" kombucha....

What do you mean? I personally think there definitely is such a thing as "shelf stable" kombucha...

 

[FearsomePenguin]

This is great! Are you brewing a variation on a beer, or is it more of an ad-hoc recipe? We've done a few variations, and it's tricky to select a tea and a beer recipe that complement each other. And let us know how the maltodextrin works out, we found when we tried it that the fermentation became kind of unstable and also produced some strange flavors.

We've done a lot of experimentation in this area, and I don't think you'll ever be able to get to the point of a shelf-stable bottle of kombucha / kombucha beer. The best thing to do if you're going to bottle condition is to keep popping bottles and trying your batch until you get to the right balance of sugar, acid and alcohol, then arrest the fermentation by putting the batch in the fridge. Otherwise, you'll end up with bottle bombs or undrinkable, way overfermented, super-acidic, super-carbonated drain cleaner. :cross:

Best of luck, keep us posted!

I agree. It probably never will be completely stable, but it should be manageable. Managing sugar content will help a lot and a key indicator is having some testers ready to pop at various intervals. The joy of Kombucha beer is that it is a little unique every time. That is also the challenge. If it carbs up in just a few days, you might want to be concerned.

Also, make sure you can drop the fridge temp into the 30s. That will help stop most any biologic process.

 

[FearsomePenguin]

What do you mean? I personally think there definitely is such a thing as "shelf stable" kombucha...

There are plenty of companies that do a lot of filtering to stablize their product for market shelves. But, at that point, your are also pulling out a lot of the great elements that make Kombucha what it is. The raw product has little alcohol, natural flora of yeast and bacteria, and possibly some strands of scoby cellulose that will settle out. Much of that can be lost in heavy filtering.

 

[snarf]

Simple logic: if the kombucha is not shelf stable, then it was bottled too early

In my opinion kombucha is primarily a gluconic acid ferment and not a acidic acid ferment. Hence, if done properly, the kombucha shouldn't get overly sour (that is, high gluconic to acidic acid ratio) when fermented for extended periods of time!

Just my two cents.

 

[FearsomePenguin]

Simple logic: if the kombucha is not shelf stable, then it was bottled too early

In my opinion kombucha is primarily a gluconic acid ferment and not a acidic acid ferment. Hence, if done properly, the kombucha shouldn't get overly sour (that is, high gluconic to acidic acid ratio) when fermented for extended periods of time!

Just my two cents.

Not if you want raw Kombucha. Refrigeration slows the activity, but it doesn't really stop it, which is what you want if you want the probiotic elements to survive (Otherwise, just pasturize it and call it good). Depending on the travel time, condition of travel, shelf of retail shop, condition of shelf of retail shop, etc... you would be hard pressed to guarantee stability. Home kombucha is typically shelf because you're only making a few gallons at a time.

 

[Owly055]

Simple logic: if the kombucha is not shelf stable, then it was bottled too early

In my opinion kombucha is primarily a gluconic acid ferment and not a acidic acid ferment. Hence, if done properly, the kombucha shouldn't get overly sour (that is, high gluconic to acidic acid ratio) when fermented for extended periods of time!

Just my two cents.

Unfortunately there is nothing to bear out your assertions which contradict the studies that have been done on kombucha.... and there are a number of them. The two organisms that are universally present in kombucha are a specific acetobacter, and a yeast of the saccharomyces family. Gluconobacter are a minor player that may or may not be present. Acetobacter will produce some gluconic acid as well as their primary byproduct acetic acid. It is however hardly enough to refer to the fermentation as being primarily a gluconic acid fermentation. I suggest that you read up on it.

H.W.

 

[snarf]

Sure

"The usual concentration of acetic acid consumed in Kombucha is 10 g/L (1%) (4). Gluconic acid is also present in substantial quantities, about 20 g/L (2%)"

This was taken from:

Determination and characterization of the anti-microbial activity of the fermented tea Kombucha, C.J. Greenwalt, R.A. Ledford, and K.H. Steinkraus, Department of Food Science, Cornell University

If the acetobacter produce more gluconic acid than acidic acid, then IMHO you might as well call it a gluconic acid ferment...