Question about alcohol and brewing time - pregnancy

[giantswing]

Hello,

I am new here and 20 weeks into my first pregnancy.

I've been brewing kombucha at home for years and have read that most home brews have <0.5% ETOH. Always test the PH, no mold or contaminates ect.

I brew mine initially for one week, bottle it, add 0.5 tsp sugar, and usually drink it a week later, so two or three week max total fermentation time.

I bought a hydrometer and tested the ETOH content and it came up 2.6% after I tested it on my oldest batch, at three weeks. I was shocked! I've been drinking this stuff my whole pregnancy!

I was wondering if a) could the added sugar and pH affect the readings, and b) in your experience, how long does it take to get that much ETOH produced? It seems very high to me!

 

[brewshki]

I am not really familiar with ETOH. However, with the hydrometer, you can measure the original and final specific gravities. Using those numbers, you can plug them into an equation and then come up with the alcohol content. most hydrometers have multiple reading scales. the one you mentioned, I don't think measures the actual alcohol in it. can you take a picture of it and post?

 

[giantswing]

The initial reading using the unfermented sugar tea was 1.04 and the final bottled product reading was 1.06. Per calculation final ETOH volume was 2.63%.

I tested stuff that was fermented for one week and stuff bottle and fermented a total of two weeks and they both came out the same percentage.

 

[kristiismean]

The initial reading using the unfermented sugar tea was 1.04 and the final bottled product reading was 1.06. Per calculation final ETOH volume was 2.63%.

I tested stuff that was fermented for one week and stuff bottle and fermented a total of two weeks and they both came out the same percentage.

I think you have the numbers mixed up! If the unfermented is 1.04(0) and the final bottled product was reading 1.06(0) then the abv is -2.63% (0)


if you are not mixing it up, when you add sugar, the gravity just goes up...

 

[giantswing]

Oops you are correct; switch the numbers; initial reading was 1.06.

 

[Yooper]

It sounds like your SCOBY has more yeast (which produces the alcohol) and less of the other things like lactic acid bacteria and vinegar bacteria. But yes, it sounds like your kombucha is over 2.5% ABV.

 

[NoIguanaForZ]

I'm not a doctor, but based on my understanding alcohol's effects on developing fetuses are dose-dependent, just like its other effects. It sounds like you've been trying to be conscientious, so I'd assume you're not gulping gallons of the stuff. I would suggest 1) talking to a doctor, 2) backing off until you can, and 3) not panicking in the meantime.

 

[Yooper]

It sounds like your SCOBY has more yeast (which produces the alcohol) and less of the other things like lactic acid bacteria and vinegar bacteria. But yes, it sounds like your kombucha is over 2.5% ABV.

I was thinking about this in the middle of the night (why oh why do I do that??????).

I'm pretty sure I'm wrong, which should be comforting to you!

I am NOT a microbiologist, and generally as wine/beer maker, we look at the SG as a mark of yeast activity and attenuation. Generally, saccharomyces cerevisiae is the species used.

But when dealing with a SCOBY, other microbes ferment the sugar as well, and my guess is that they do NOT have the same metabolic activity and produce ethanol and c02 as a result. In addition, acetobacter (the bacteria that produces vinegar) actually digests ethanol to produce vinegar and water.

I thought about this because I also make vinegar. I put out no-hopped beer, and lower ABV wine, and add a mother of vinegar. When the vinegar is done, there is no alcohol left in it because that's what the bacteria uses to make the vinegar.

I don't know nearly enough about the mechanism of lactobacillus and other microbes to say what the content actually is made up of in the end, but based on what I was considering last night (when it all made sense in the middle of the night), I think your original guess of very low ABV is indeed correct.

I think a hydrometer or vinometer is just not the right tool for kombucha as a measure of fermentation.

 

[giantswing]

That's what I was wondering too Yooper!

I couldn't find a ton of credible literature to back it up, but if the microbial species that is responsible for the Kombucha fermentation is spitting out a ton of acid/vinegar than what the hydrometer reads will change regardless of what the product is (acid vs ethanol) as it measures changes in sugar as it is metabolized?

I have scoured the internet but haven't found anything definitive, and will lay off the home brewed buch just to be safe.

Regardless, thanks all for the replies. Just hoping for a healthy baby!!