What kind of nutrient do you use? Some people use Fermaid K and some just use regular nutrient which is DAP. For regular nutrient, the dose is 1 tsp per gallon. So if you're making 6 gallons you need 6 tsp total. So split the dose in half. 3 tsp right when you pitch the yeast, then the other 3 tsp before you hit the 50% dry stage. Always step-feed nutrient so that you don't get sluggish or stuck ferments and have no problems with H2S which happens when the yeast become stressed due to lack of nitrogen. Don't add nutrient past the 50% dry stage because the yeast can no longer utilize it.
Fermaid K dosing is slightly different--last dose at 1/3 sugar depletion.
We do the first rack when there's quite a bit of debris--about 2 weeks after being racked into a carboy. But then, most of our ferments are done with grapes and fruit so there's more debris than with a juice bucket. You may only need to rack one time with bucket juice. But after the first racking, if you see another 1/2 or so of lees go ahead and rack it off. Now when you get to that light dusting of lees on the bottom, allow the wine to bulk age on them.
We always test for SO2. We test at that first racking because much of the initial SO2 that the bucket came with will be bound up by the sugars,bacteria, yeast,etc. And most buckets have little SO2 on them so that it doesn't interfere for MLF. So by the time your primary ferment is done, 9 times out of 10 your SO2 is going to be very low. The amount of free SO2 you need is determined by the PH of the wine. So this is another reason to take PH readings. Once you have the free SO2 up to where it needs to be, you probably don't need anymore as long as you're not removing the airlock, thieving from the carboy, etc.
If you go to
www.morewine.com in their Moremanuals section you can read all about SO2, and more, for free.
