Re: Specific Gravity - Primary Fermentation

Keep it attached. Your yeasties seem to have plenty of oxygen. Also, dont sweat the exact day you do the racking. The wine is very forgiving.

Congrats on starting your first batch!

KB

"Change is the law of life, and those who look only to the past and present are certain to miss the future."

Many do the primary in a big bucket, in which case there is no place to attatch the airlock.

If you ferment in a 23 L carboy there may not be enough headroom in your fermenter, because it may bubble and foam too much, etc. A food grade anti-foaming agent can help, but it's also better to use some kind of larger primary fermenter.

I use a larger glass 6.8 gallon fermenter as a primary, and that leaves quite a bit of headroom, and I attatch the airlock. The yeasties seem to have no trouble at all without any oxygen, and in fact, yeast produces enormous amounts of CO2 gas, which they generate in part to help kill off enemy bacteria, so it seems obvious to me that yeast don't require any oxygen at all.

LG

"Brand>Newbe question - I'm making wine for the first time using a wine kit and

I do not use an airlock during primary but it is obvious that you are opening it every day and checking it and probably stirring it (stirring is a good thing during primary) so that is giving the yeast all the oxygen they need. Leave it on or take it off will not matter. Now if you were just setting it up, putting an air lock on it an leaving it, it would be better to not have it. But if you think about it, the air lock is to keep air away from the must. You are opening it and stirring it and testing it. The air lock is irrelevant during this phase.

Ray

Hi Brandon,

During the primary fermentation stage of wine production, yeast converts sugar into alcohol. A by product of this is Carbon Dioxide (CO2). As the CO2 is heavier in weight than oxygen, it covers the top of the wine must, protecting it from oxidisation due to oxygen contact. Once the primary fermentation has slowed or finished, the CO2 production ceases. It is at this point we must add sulphur dioxide (SO2) in the form of PMS or SMS to the wine to protect it from oxygen contact and limit the amount of air by fitting an air lock.

I have found with some wines (especially country wines made with fruit other than grapes) that if I do my primary fermentation using an airlock, not enough oxygen mixes with the must and I often get rotten egg gas smells (Hydrogen Sulphide) which are quite unpleasant. This is why I always do my primary fermentation in an open fermenter covered with a cloth.

Regards

AB1

Thank you all for the information. This is a really great group and the more I read the more I realize how little I know.

Brandon