Just a quick redux of the stirring issue for my (Winexpert) kits:
<ul>
[*]If you've fermented at the right starting volume, the right
temperature, and you've achieved the recommended specific gravity
levels, then you'll be able to stir the wine to de-gas within the
time-frames specified in the instructions.
[*]If the wine was started at anything other than the full 6
US-gallons (23 litres) or it was fermented cooler than 68 F, or if your
gravity readings were not at or below the recommended levels when you
did the process, you will not experience consistent success.
[*]You only need to stir a Winexpert kit four times.
<ul>
[*]On day one, you have to beat the snot out of the must to mix it
properly. A good, arm-cracking one minute stir to froth it up and mix
the juice and water will get you off to a good start and a thorough
fermentation
[*]On fining/stabilising day, after you've double-checked the SG, then you can first stir the kit without adding anything--and without racking it off the sediment!</span>
(Unless it's a Crushendo kit, but that's covered in the
instructions--no racking for any other kit. If you choose to rack it,
you will not experience consistent results. This first stirring
will be to greatly de-gas the wine, prior to adding any of the fining
agents or stablisers. Beat the hell out of it, for one full minute. Use
a watch or clock--one minute is a lot</span>
longer than most people think. If you can scractch your head with your
stirring hand after that one minute, you haven't stirred hard enough.
It should be an all-out blizzard of effort that costs you all of your
strength, and you should see spots in front of your eyes (see why I
tell people to buy a drill-mounted stirring whip?)
[*]Add the sorbate and the sulphite, and stir again, for one full
minute. This time you may break one or two small bones in your stirring
arm, but don't slow down--if anything, stir harder.
[*]Add the fining agent and the F-Pack (if the kit has one) and
stir for one more full minute. Have the paramedics standing by with a
bag of ice to carry your stirring arm to the hospital where it can be
re-attached. Top up with water and call it a day.
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Now, if you have fizzy wine after this regimen, you don't have a
stirring issue. You have eiither got an incomplete or ongoing
fermentation, or you're mistaking foam for fizz, or you may have an
inicipient lactic acid bacterial infection that is making a bit of CO2
in the wine.
The amount of stirring described will reduce SO2 slightly in the kit:
however, the amount it is reduced by is minimal, because rather than
uptaking oxygen during this process, the wine out-gasses CO2, which
actually scrubs some of the oxygen out of the wine.
If you stir at a time when the wine is not saturated with CO2, you may
experience reduced SO2 and potentially expose the wine to oxidation.
But then, why are you stirring wine if it's not fizzy?
Hope this helps outl
Tim Vandergrift
Technical Services Manager, Winexpert Limited.