SCOBIES are forever ?

[mevla]

Hello, I'm rather new to brewing kombucha and have made so far a few batches, all with second fermentation (apples and ginger). I'm totally sold. It tastes so good.

Are SCOBIES everlasting ? How to tell if it's still going good ? Is there a way to gauge how well it does, how potent it is ? And, if only tea and sugar are used, no SCOBY, and left the same amount f time, would that result in somthing similar ?

Cheers.

 

[rushpapers]

People think the pellicle is what holds the culture of bacteria and yeast. It is not. The kombucha liquid itself is the culture. You need to save 20% for the next batch. As long as you make new batches with proper sugar, proper nitrogen, proper pH, etc, and it doesn't get infected you can grow culture forever.

Some people like to continuous brew using a vessel with a spigot, pouring into secondary bottles from the bottom and refreshing with new sweet tea from the top. It works well except for the fact that continuous brewing concentrates alcohol.

 

[mevla]

I waited for the current batch to complete, didn't want to disturb it, so I can take pictures. Thanks for mentioning that the culture is in the brew. At first I didn't get it, now I do.

So here's how it looks like, top and bottom. From what I understand so far, the thin top is discarded while the bottom, much thicker, is another SCOBY growing.

Is it possible to gauge the 'potency' (for lack of a better term) of a brew by how well the 2nd SCOBY is doing ?

And, I do not check for nitrogen and pH. Would like to, though, at least to establish a reference. I guess I can get pH strips, but how does one go about testing for nitrogen ?

Also, is there a minimum amount of tea ? I currently use 7g of slow-black white tea large assamica leaves from to 2 years ago for 3l of water, to which is added 2 cups of the previous batch.

This is the thin top layer. This one I discard.

And this is the thick bottom layer. I am leaving it as is for brewing another batch.

 

[rushpapers]

...not exactly.

What I stated in the past, and will restate, is that you don't need a pellicle to produce kombucha. Many people think the pellicle--improperly referred to as SCOBY--is what makes kombucha. It does not. A pellicle is like the shell surrounding a nut--a protective barrier.

What does make kombucha... is kombucha, and it is often referred to as "Starter."

"Starter" is 20% mature kombucha that you use to inoculate sweet tea. For instance, you need 1 gallon starter, to inoculate 4 gallons sweet tea, making a total of 5 gallons.

Here's an illustration of how I make large batches of kombucha.

Each takes 2 weeks to mature, but I have them fermenting simultaneously.

I throw away all pellicles that form.

 

[mevla]

Thanks for your patience. So it means that the neighbour, instead of giving me a thick SCOBY, could have given me some 2 cups of a 'ripe' kombucha brew and it would have worked all the same for me to start making kombucha ?

By the same token, a commercially bought kombucha brew can be used to make one's own kombucha batches ? Or do they pasteurize them at the commercial level ?

The role of the thick pellicle is to protect the brew ? If I have a good ratio of starter vs. sweet tea, is it possible to throw away the thick pellicle altogether and make a new batch ?

To make 125 gal. batches, do you run a kombucha business ?

 

[rushpapers]

So it means... 2 cups of a 'ripe' kombucha brew and it would have worked all the same for me to start making kombucha ?

Absolutely correct.

By the same token, a commercially bought kombucha brew can be used to make one's own kombucha batches ? Or do they pasteurize them at the commercial level ?

Correct, BUT, many commercially produced kombuchas filter their kombucha. The filtration reduces the potency of the kombucha so that it stops fermentation inside the bottle. Therefore, making kombucha from a comercial bottle can be troublesome because there is not enough active culture.

The role of the thick pellicle is to protect the brew ? If I have a good ratio of starter vs. sweet tea, is it possible to throw away the thick pellicle altogether and make a new batch ?

Yes, you can get rid of the pellicle altogether. I throw away all pellicles that form and have never had a problem.

 

[mevla]

Thanks. Very useful. Now is it possible to measure the 'potency' of a kombucha brew ? How would it be possible to clearly demonstrate that there's a difference between a kombucha brew, and one that was made only from sweet tea w/o any kombucha starter nor pellicle ?

 

[rushpapers]

You know how potent kombucha is based on the acidity.

Kombucha works like this:
1. The yeasts make alcohol.
2. The bacteria eat the alcohol and turn it into glucuronic, gluconic and acetic acid.

Therefore, a measurement of pH is a clear indication of how your booch is progressing.

Furthermore, there's an art to making kombucha. You become sensitive to the smell and taste. I can smell when my kombucha is mature. Of course I always test it to be certain.

 

[mevla]

I've seen digital pH testers sold at amazon that seems good for this use. What would be the pH range to look for in a healthy kombucha brew ? Also, regarding pH, what is the role of tea, does it have any ? Sugar certainly affects the pH of the initial brew when a new batch is started. Additionnaly are there any pH values to look at the beginning of a new batch to assure a good unfolding ?

 

[rushpapers]

I use a Milwaukee pH600 digitL pH meter. I spent $17.

Kombucha is commonly 2.5 to 3.5 pH.

Tea itself is acidic. Black tea is generally in the 5.0 pH range. Tea provides the acidic environment for kombucha. It also provides nitrogen compounds, carbohydrates, enzymes and vitamins, plus caffeine and theophylline... and a whole host of trace elements.

When starting a batch of kombucha, aim for 4.0. In fact, NYS, requires kombucha producers to start their kombucha at <4.2 pH. Pennsylvania's laws on kombucha have similar requirements. <4.2 is acidic enough to ward off any infection and give the booch a nice acidic environment to thrive.