I messed up

[David Goldsmith]

I messed up: I went ahead and started my fermentation w/ incomplete information; primary offense: I didn't take an s.g. reading at the outset (and even if I had, I added more juice and water after a few days, and then maple syrup and water after another few days, so that initial reading would have been moot, yes?)

Nevertheless, the brew appears to be fermenting nicely (~4 gallons liquid continuing to generate CO2 at a rate of about an 0.5 inch^3/sec. at 60-70 deg. F; sorry for the antiquated units); my primary concerns are: a) to stop before it starts to go to vinegar (I don't really care that much about the final alcohol content); and b) that I don't grow anything toxic (other than alcohol).

Am I correct that as long as I keep the airlock on, I can just let it continue to brew until it stops bubbling (indicating that the alcohol has gotten to the point where it has killed off the yeast that produced it), and then I should bottle it--air tight--right away (it's exposure to oxygen that makes the yeast produce vinegar instead of alcohol, right?) And what, if any, is the risk of growing something that would result in "food poisoning" from drinking the final product?

Thanks!

 

[RPh_Guy]

I didn't take an s.g. reading at the outset

You don't actually need it, it's mainly for ABV calculation.

to stop before it starts to go to vinegar

Vinegar is only created by certain microbes and only in the presence of oxygen.
Protect from oxygen = no vinegar.
For added protection, add sulfite after fermentation completes.

that I don't grow anything toxic

No worries, pathogens and toxins don't grow in wine.

Am I correct that as long as I keep the airlock on, I can just let it continue to brew until it stops bubbling (indicating that the alcohol has gotten to the point where it has killed off the yeast that produced it), and then I should bottle it right away

You can, but normally you should:

• Confirm fermentation has completed by taking multiple FG measurements.
• Wait for it to clear (and/or use fining)

And what, if any, is the risk of growing something that would result in "food poisoning" from drinking the final product?

None.

 

[David Goldsmith]

Thank you for your input; what does FG stand for?

Plus, new development: all through the fermentation so far, there's been a white foam on top (it gets dotted w/ wine-colored blobs of foam between stirrings, but is all white immediately after stirring). Now, suddenly, in a matter of (many) seconds, all the foam has gone away; the airlock is still bubbling just as fast, but the surface is now very decidedly different, and it happened very quickly, right before my eyes: any idea what this signifies? Thanks again.

 

[RPh_Guy]

FG is Final Gravity, the specific gravity measurement of the wine when it has completed fermentation, or perhaps after fermentation has completed and you stabilize and backsweeten it.

OG is Original Gravity, the specific gravity before fermentation.

Foam is common during fermentation. It's fun to watch. Nothing to stress about
Cheers

 

[Blacksmith1]

My personal theory is that as the yeast eats the sugar the liquid looses surface tension and as a result the CO2 bubbles (foam) pop sooner resulting in less foam as time passes, at some point it has to be noticeable. Mine will do it after several degassings..... well also on their own at some point.

 

[David Goldsmith]

FG is Final Gravity, the specific gravity measurement of the wine when it has completed fermentation, or perhaps after fermentation has completed and you stabilize and backsweeten it.

OG is Original Gravity, the specific gravity before fermentation.

Foam is common during fermentation. It's fun to watch. Nothing to stress about
Cheers

I wasn't worried about the foam, I was worried about it's quick disappearance, but it's returned, so evidently it was a transient of some sort.

 

[bracconiere]

yeast are anaerobic(SP?) fungi, acetobacter are aerobic bacteria....yeast just go to sleep, they don't make acetic acid...

 

[RPh_Guy]

yeast are anaerobic(SP?) fungi

Saccharomyces is a facultative anaerobe.

yeast just go to sleep, they don't make acetic acid...

Some yeast do make acetic acid, but only when both oxygen and alcohol are present.

See also: Cunningham's Law