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

"Brandon" > wrote in message >...
> Newbe question - I'm making wine for the first time using a wine kit and
> after reading some of the posts here, I'm not sure I should be using an
> air-lock during the primary fermentation as oxygen is required to assist the
> yeast in converting the sugar into alcohol and SO2?
>
> According to the kit instructions, I should rack the wine into the secondary
> when to Specific Gravity reaches 1.010 or less, which should occur from 5 to
> 7 days after the yeast is added.
>
> Here are my current readings:
>
> Day # Specific Gravity Temp of Must
> 1 1.080 76 F (Yeast Added)
> 2 1.070 72 F
> 3 Didn't Check 74 F
> 4 1.050 72 F
>
> At the current rate, I'm guessing the wine should be ready to rack around
> day 8? Should I remove the airlock or keep it attached?