ML with residual sugar, a problem?

Hello, I posted earlier about my Zin with 26 brix. I used pasture red yeast and I can taste some residual sugar in my wine. The wine is below 0 brix .996 SG last time I checked and I ordered some clinitest tablets to figure out how much sugar is left. How much is too much? Should I add some killer yeast? Also I read somewhere that residual sugar and MLF are not a good combination, but how much residual sugar is not clear since most wine would have some residual sugar, right? I used Viniflora oenos.

Also for those interested I checked the ML progress with paper chromatography and there is clearly some Malic acid left and there is a spot that should be lactic acid so I guess the conversion is still underway and when I had my samples in a 50 ml tube I had to open it every once in a while to let gas escape. The pH is now 4.1 after microwaving (4.22 before) and I got a TA of 5.5 but this could be wrong because instead of measuring volume I weighed the flask and then brought it back up to the original weight after microwaving, but I forgot that alcohol does not have the same density as water (.78 grams per ml instead of 1 gram per ml so actually the real value may be slightly lower if it is significant at all) but it doesn't matter until MLF is complete since the value is going to change).

-Alex P

Reply to
Alex
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MLB can metabolise sugar yielding undesirable products (e.g. acetic acid). "Safe" r.s. levels might be considered as < 2 g/l of reducing sugars - so you *should probably* be just OK in this case.

The difference is insignificant - you need not worry. Say your wine is at 12% abv and your sample was 50 ml total. The weight of this sample is 48.8 grams (50 ml * 0.12 * 0.792 + 50 ml * 0.48 * 1). So when you reconstitute the boiled sample with water to the original weight (48.8 g), the reconsituted volume becomes 48.8 ml (it's all water, 48.8 g 48.8 ml). The difference (50 - 48.8 = 1.2 ml) is just 2.4%/volume, i.e. not significant.

In which case, that pH is pretty high and it would be nice to get it down!

Ben

Improved Winemaking

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Reply to
Ben Rotter

That pH is way too high, I would try to get it to at least 3.5 with tartaric, especially if you want to do MLF. I would agree with Ben on

0.2% RS. Joe
Reply to
Joe Sallustio

I wouldn't worry about the sugar. As the others have said, MLF and sugar can give problems with volatile acidity but most sources aren't as strict as they said (0.2%) in what you should have. Wyeast recommends adding their culture, for example, when primary is 1/2 to

2/3 through - in other words, 8-12 brix. I've read about at least one commericial winery doing it at 6 brix. Another manufacturer of dry ML culture suggests only that the juice used to expand the culture be below 20 brix.

So the level of sugar you have should be no issue as far as MLF goes. At SG .996 you definitely have some but whether it's worth restarting fermentation is a matter of your taste. Plenty of wineries have discovered that a little residual sugar helps sell supposedly "dry" wines, maybe you'll like it. As the others have said, I'd be more concerned about a pH of 4.1.

- Mark W.

Reply to
Mark Willstatter

Uh oh. My grapes were running at 29+ brix so I pitched the ML culture real quick to minimize any problems with high alcohol.

Any thoughts on options at this point? what should I look for (taste for)?

Reply to
Patrick

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