How do you sulfite?

If you are aging in glass carboys, keeping track of sulphite additons and recording in a log and adding a tad more during rackings is not a bad approach. If, however, you are aging in barrel, then you need to do some testing. Barreled wine will loose free SO2 quite rapidly. The very best approach is Aeration/Oxidation testing. The apparatus is not cheap but it is the very best for testing red wines. I know you can get apparatus at "Wine, Wine & More Wine" and from "Presque Isle". Some on this news group have devised their own setup. Or - you can send in a sample to such places as "Vinquiry" and they will do an AO test for about $12.00. I also think that "Wine, Wine & More wine" will do this test also. I do not know their price. This may be a bit much for a five gallon batch but if you have a 30 or 59 gallon barrel, it makes it a lot more reasonable approach. 30 to 60 gallons of wine is a big chunk of wine to loose for being too frugal to spend $12.00

Hope this helps.

You need to know 2 things in order to intelligently sulfite your wine:

(1) How much free SO2 is already in there, and (2) What the pH of the wine is.

That's it.

Measuring the pH is easy. You use a pH meter. Forget about pH papers. They don't resolve to 0.1 pH units. Papers are useless for that.

There are 4 ways to measure the free SO2:

(1) Ripper titration, which is easy for whites and harder for reds,

(2) Titrets, which some swear by and others swear _at_,

(3) Aeration/oxidation, which requires a small investment in apparatus and chemicals - but nowhere near the $300 or so I see mentioned by others. You really don't need all that fancy glassware. A small aquarium pump, some glass and rubber tubing, some rubber stoppers, a graduated pipette and a couple of small flasks will suffice. And finally,

(4) Send a sample to a commercial lab. If you're making large batches, even as an amateur, this makes sense.

Tom S

I guess I should have mentioned that I make wine in small batches, about 20 gallons or so a year, so don't think I want to spend money for lab testing or aeration/oxidation at this point. I think we will be going the barrel route in the future and then will have to weigh the different options then.

Is there a way to estimate SO2 losses over time in a carboy?

Also, no one has mentioned the method you use yet.

Well, here is what I do for 5 gallon carboys:

Each rack I add 1/8 teaspoon of potassium 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 addition. If the pH is higher (>3.5), I round the spoon on later racks. I don't rack much more than 3 or 4 times.

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 titretes. 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 gassy, 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

Joe