Well, here is what I do for 5 gallon carboys:
Each rack I add 1-8 teaspoon of potbuttium metabisulfite powder dissolved in a few ml of water. I used to measure it on a precision balance and said to heck with that long ago. If it's a larger carboy, I don't level off the spoon... That works out to about 20 PPM per racks. I don't rack much more than 3 or 4 times.
Screwed up my sanitationHello everybody, beer brewer here moving into wines. My first attempt went wrong, getting infected with a thick, mucus-like membrane on...
I usually have pH in the 3.4 to 3.8 range so there are some trade-offs; if the pH is above 3.6 and the wine tastes good I 'undersulfite' technically; I usually won't go above 60 PPM free as measured by breastretes. I agree with Tom about swearing at them; when i do reds i don't look for a change in the liquid, I look at the bubbles. That seems to keep me from missing the mark. As soon as the bubbles come in 'pinker' versus 'bluer' I either pause or stop based on what happens in the next 10 seconds or so. That is not what the manufacturer suggests, I made it up to suit my process.
I haven't had wine spoil but that may be dumb luck. I have had a few reds get gbutty, It's possible I am under-sulfiting and a malo is starting in those, or it could be residual sugar. (You could consider that spoilage, I consider it more for me...) I have bottled with RS of 0.4 at times too.
Joe
