I drank some very nice Mâcon (la Roche Vineuse) the other night that had some precipitate. At first sight, it looked like thin bits of lemon peel. The taste was like the wine, but more acidic. Is that bitartrate? (I posted this on Wine Talk but nobody answered. So I’m going to the experts!).

Looked like lemon peel? Not like crystals?

did it look like this here pic. of potassium bitartrate crystals?

Sort of, but there wasn’t so much of it. Perhaps the crystals had conglomerated on the bottom indentation of the bottle, then broken off when poured out, so that they were in strips. One side of the strip was much smoother and a bit thicker, the other side looked very ragged (so maybe the xtals were growing on that side). Between the shape and the color, at first glance they looked like lemon peel, but when you examined them more closely not so much so.

The smooth side must have been the side of the tartrates that formed on the glass. They probably just broke off as you said.

Thanks, L! No end to what you can learn while living in a tank, is there neener ?

Incidentally, do they sometimes just form, or only when the wine gets too cold?

It’s most likely tartrates. If a high acid wine hasn’t been properly cold stabilized, they can throw tartrates when they get cold for a long time or sometimes with age… nothing to worry about. Wine is full of tartric acid anyway…

Thanks. It didn’t bother me (there wasn’t that much of it anyway), I was just curious.