I am making wine from wild grapes and elderberries and the ph measured at 2.8. Is malolactic acid fermentation the right answer for improving the acid level? Should I plan to do this on all batches in the future?
Short answer, no. Wine must doesn’t have nearly the buffering capacity of beer wort, so it doesn’t take as much acid to drop the pH to really low levels. A better measure for the acidity of wine is titratable acidity, or TA. Do you have a TA kit? That’ll give you a better indicator.
More importantly, how does it taste? If the wine is still young, it’ll have some carbonic acid, which will reduce as the carbon dioxide off-gasses. How did you measure pH? Strips or calibrated pH meter? Strips can give you an erroneously low measurement.
Malolactic fermentation is actually pretty tough to get going with oenococcus oeni. It seems to be a pretty sensitive microbe. You can also use pediococcus, which is a bit more robust. Both produce large amounts of diacetyl, which gives the “buttery” flavor reported from MLF. Might be ok in your wine, might not. And it really only works to increase pH if you have significant malic acid in your wine.
Not saying you shouldn’t try, but make sure you’re doing it for the right reasons.
Thanks! I used a Ph meter, I don’t have a TA kit. Fermentation is slowing now and the Ph reading is up to 3.05. Maybe it’s ok?
That’s not a bad pH for wine, I’d roll with it. Here’s hoping @rebuiltcellars sees this thread, he’s the expert here. I don’t think you need to use MLF, though, for acid control. For flavor profile, maybe.
I agree with Porkchop, you are probably OK as is.
pH of under 3.1 can sometimes cause issues with fermentation; some yeast strains are sensitive to low pH, but if fermentation is looking to finish and not get stuck, there isn’t a reason to worry.
You can get a TA kit pretty easily, and it gives a better read on how the wine will balance. pH is a critical measurement for microbiological stability; TA is better for giving clues for taste.
MF is a style thing, and it can be very difficult to do. I’ve only tried a couple times to do ML without planning for it ahead of time (as in, before I even got the grapes), and both times it failed. You typically need to add ML nutrients, be very careful about any sulfite additions and even plan on which yeast strain you use. That said, I’m out of practice. Haven’t done ML since I last made wine from grapes - 10 years ago.
I used malolactic on my last cider and it definitely helped, though I still think the cider is too tart for MY own tastes (although I must admit I have a sweet tooth – I’ll be adding xylitol).
However I have no experience with very tart wines.
Based on my chemistry background, IF I found any wine to be extremely tart, I might consider adding baking soda about a half teaspoon at a time (per 3-5 gallons) until the edges were smoothed. However keep in mind this does add a lot of sodium, which could potentially make it taste salty as well, so you wouldn’t want to overdo it either.
Seems like it might just need more age to mellow it out. But like I said… I’m really not a wine guy, either.
Most of my ciders go through a natural MLF at around 6-months, as the weather starts to warm. Mostly because I don’t do anything to prevent it, like pasteurizing or adding sulfites. Big pitch of yeast dominates the fermentation for the first month or so, and then the slower growing microbes like pedio can have their contribution. Based on the timeframe, I’m guessing that the MLF is being done by pedio, since it’s already on the apple skins. But I’d say that it makes an improvement, with a softening of the acid character. As long as you can get past the gooey, snotty phase it goes through.
The one time I used oenococcus was with a blackberry wine, and the stuff tasted like movie theater popcorn for a good year from all the diacetyl. Not pleasant.