TA of 1.7% - What to do?

jowine · Oct 20, 2014

I have fermented about 5 gallons of a cold climate red grape juice, Marquette, that was picked a bit early due to an early frost. Fermentation was already underway when I received the juice, and the potential alcohol read at about 10% when I tested it. I figure it was about 20-25% fermented. It had a very sour taste. I added about 1/4 tsp of sulfite to the must, let it sit overnight, then added the yeast the next morning. It fermented out in about a week. It still tasted very sour, but fruit tones were there, just very much overshadowed by the sourness. I did an acid test, and it figured to be about 1.7%, which is obviously very high (it was the first time I had ever done one so I did it few times with similar results). I racked it off of the lees and added about 1/8 of a teaspoon of sulfite to the carboy.

I'm not sure where to go from here. I realize the wine is very young and needs time to mature, but I've never had one taste this sour before at any time in the process. I've considered a malolactic fermentation, but I've never done one before and not sure it makes sense here. Then I found an acid reducer online and considered that.

Anything thoughts on a next step to try to smooth this out would be appreciated!

Thank you.

Joe

ColemanM · Oct 20, 2014

Marquette definitely needs MLF. Your so2 may be a bit high for most malolactic bacteria to work right now. I would either splash rack to reduce the free so2 or let it age for a few months, then inoculate with a so2 tolerant strain of MLB. I do a MLF to my frontenac that usually start out about 1.4 TA and use 71b yeast. Those two measures greatly help.

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grapeman · Oct 21, 2014

You don't mention the pH of the must. You should check that also because that will affect what mlf if any will work with it. To be that high in TA I suspect a pH of around 2.9 or a bit lower which will make starting any mlb difficult. There are acid reducing chemicals you can use such as Acidex, but be careful how much you use. Here is a link to a page with more information http://www.101winemaking.com/acidex_instructions.htm .
If you can't do an mlf on it, then you could consider blending with a low acid wine or even sweetening it as a last resort.

jowine · Oct 21, 2014

Thanks to both of you for the help. I think I'll wait the couple of months for the sulfites to dissipate and try to find the so2 tolerant strain of MLB. I haven't checked the pH, but figured it to be low as you mention, grape man, considering the TA level. I will check it and maybe try the acid reducer before the MLB.

The blending is something I'm considering down the road. This is my first foray into cold climate juice, which I'm finding to be very different from the juice I've used for several years from California. But I'm committed to learning how to work with it, and I'm hoping to get off to a good start.

Thanks again.

GreginND · Oct 22, 2014

You will need a low pH tolerant MLB. I used MB31 on my marquette last year and it worked well.

grapeman · Oct 22, 2014

I routinely use the MB31 strain, especially with Marquette and Frontenac.

spaniel · Oct 22, 2014

Apologies for a partial hijack, but where do you obtain multiple MLB strains like MB31? I recall searching around last year and not finding much in the way of MLB options, especially from a common source like Midwest.