Cold mash?

My buddy, while drinking cold brewed coffee, asked whether or not it would be possible to extract sugars from the grain without being at a high temperature? I feel confident in having definitively answered no. I do still wonder what would happen.

Using the same principles as cold brew coffee, what would happen to the water if you were to steep grains in it at fridge temperatures for 48 hours? It seems reasonable to assume that the powdered residues would dissolve into the water. Outside of that, I can see it acquiring a malty flavor but would still bet the OG would be somewhere under 1.005.

What do we think? Anyone tried this?

There are at least a couple of cold-steeping threads on this forum. Several ways to do it and it does work - you get a smoother roast character as a result.

You could only hope to do this with crystal/caramel malts where the starch has been converted to sugar prior to drying, or roast/black malts where the starch has been burnt and you’re mostly just getting color/flavor components. Everything else is starchy and needs the warm temps for the enzymes to convert starch to sugar.

That said, I guess grains do germinate and grow at normal temps, so perhaps given enough time the amylases would do their work. You’d be racing the lactic acid bacteria though.

Conventional wisdom says that enzymatic action won’t be significant at those temps, but I can’t say I’ve tried it. I’d imagine room temp would be better than fridge temps. I guess you could steep grains that don’t require mashing that way.

At room temp, though you could be looking at a sour mash after a day.

I think that’s how they do some sour mash whiskeys.