Several questions have come in along those lines the last few days. “Dry butter” is a term that French pastry chefs frequently employ, usually in regard to the cultured butter they use for laminated pastry. I confess I don’t know what the technical definition of dry butter is in France (France being France, I’m sure it’s codified under law somewhere). I do know this: normal American butters are usually about 80% butterfat, 17% water and 3% protein. That’s “wet” by European standards, where butter is more like 82% fat and 15% water. That, according to some pastry chefs I’ve talked to, makes standard European butter “dry.”
However butter can get quite a bit drier. The Vermont Creamery, I know, makes cultured butter that is 86% butterfat, which is the driest American butter I’m aware of. Is French “dry butter” drier still? I honestly don’t know. Perhaps someone out there who knows would care to weigh in.
One thing I do know is that no matter how dry American butters may get, they will not have the same combination of dryness and firmness that French “winter butter” has, for reason I explained below. Just like French flour, some ingredients simply can’t be reproduced in other locales. We must do the best we can with what we have. As must the French when they set out to make blueberry muffins.