Need help with acid correction

I'm suspicious of your TA measurement. Have you _tasted_ the juice? I find that it isn't that hard to tell by tasting whether the balance is right or not. BTW, what were the starting and final Brix?

If you have any shot at inhibiting ML you'd better get to it pronto. ML will quite happily go concurrently with the primary.

Tom S

Thanks Tom. I did add lysozyme 1 day into the primary fermentation.

So far, I've added 26 g of tartaric as part of the acidulated water (the initial Brix was about 26.5, and I've added 40 g of free tartaric. I checked the TA with 2 different methods on 2 different samples, for a total of 4 tests, and the results ranged from 0.35% to 0.50%. I agree that's something is wrong with my measurements.

I read somewhere that some people depend more on pH than on TA. I'm not sure if that's valid, but it would sure make life simpler.

By the way, the juice tastes "flat". I don't have high hopes. but it makes no sense to just add more and more tartaric and then be stuck with tart wine with a pH of 3.1.

As always, Tom, thanks. For those of you out there who aren't familiar with Tom S, his input is like having Pambianchi on the phone.

Lee

Lee,

Did you test the juice before you added the acidulated water and tartaric? When you got the bucket, did you stir it well when it defrosted? Brehm is vehement about that since when frozen some tartaric acid falls out as cream of tartar and you need to be sure to get the goop at the bottom of the bucket. If you didn't stir it well or left the gunk in the bucket, your initial TA might be well below what the harvest stats were. Of course, that still doesn't help you decide if you want to add more tartaric if you're happy with the pH. But, if it doesn't taste acidic enough, I'd be tempted to bump the TA some more and enjoy the benefits (less SO2 needed) of an even lower pH.

Ed

That's my method, FWIW. I haven't titrated a TA since well into the last millennium.

If it tastes flat, it is. Let your pH meter be your guide and get it at least below 3.50. If it still seems flat at 3.48 (your measurement) take it down to 3.40 and taste it again. Do this in steps until it tastes right, but I probably wouldn't go below 3.30 if I were you.

BTW, stirring in precipitated tartrate crystals will do little if anything for your wine. They won't end up in the bottle once you cold stabilize - even if they do redissolve somewhat now.

Tom S

I'm pretty sure your NAOH is bad, that TA makes no sense if you added

2 g/l. That would mean the original must had around 1.5 g/l and I doubt that would happen. You usually lose about 1g/l with stabilizing, so a guess would make your current value close to 6g/l, say 5.5 to 6.5 g/l.

You can calibrate the NAOH with Potassium acid Phathalate (I can't spell it for love nor money). If it tastes flat it is low, so I would do as Tom said too. You could use malic or citric if you don't want to impact pH as much as a FWIW. You may want to start with 0.5 g/l additions to make sure you don't overshoot.

Joe

That was my thought also, but when NaOH goes bad it normally gets _weaker_ and that makes for false _high_ TA readings.

Potassium hydrogen phthalate is a tough (and long) one to spell, so I usually abbreviate it to KHT. :^)

If it tastes flat it is low, so I would

I agree with that last, but wouldn't use anything but tartaric at this point. The fermentation has just started and citric is fermentable. Malic is OK since you are inhibiting ML, but it's diprotic (has 2 acid hydrogens) too so you might as well use tartaric.

Tom S

Just to add to what's already been suggested - I had this same problem with Pinot Blanc juice that came in frozen. It measured at 4g/L TA, so I added 2.5g/L. It tasted quite tart after this addition. A year since, the TA is at 7.3g/L, it's mellowed down a bit, but the acid is way too noticeable still. That really drove down home for me the importance of trusting your senses more than numbers, especially for TA measurements.

Pp