Back in February, we wrote about nymilk, a NY-state consortium of small-herd dairy producers who teamed up to bring some very fine milk to New York grocers and restaurants. Well, the same folks have expanded to butter, and man, is it good.
Most butters you find in the supermarket have a butterfat content of around 81% or so, with the remainder being taken up by water and milk proteins. Buy a fancy European butter, and you push that amount up to around 83 or 84%. nymilk's butter is a whopping 91% butterfat. To be honest, I've never seen a fattier butter. It's also cultured—that is, it's made from cream to which bacteria has been added—giving it a faint nutty, cheesy quality.
As far as baking with it goes, don't bother—its high fat content means that it won't behave the way a normal butter does in your cookies and cakes. You'd also end up losing the subtle cultured flavor (and that'd be a terrible thing to let go to waste).
Some of the top restaurants in the city are using it right now to finish dishes—it's great for mounting sauces or glazing vegetables, but I think it's best to use this butter for what it's truly meant for: serving at the table with just a bit of salt and some equally awesome bread.
The butter's on the shelves at Eataly, will soon be available through Fresh Direct, and is on the tables of Craft and Gramercy Tavern (amongst others!).
About the author: J. Kenji Lopez-Alt is the Managing Editor of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.