Having little to do the last few days, but no real space to fit more beer, I wrote an eleven page (single spaced) guide to all-grain brewing. It was pretty fun. I think it's not really finished yet but I want to give myself a day before I revisit it so that I don't overlook anything important.

This was actually a seguey into something that I wanted to say... what was it? Ah, while working on this, I was consulting John Palmer's How to Brew on the subject of decoction mashing. I've never actually decoction mashed, but I wanted to at least mention to the process in my guide, so I thought I should read up on the process. I read and I thought, "fucking hell, I could totally do a single decoction to mash out. This stuff about maliard reactions totally makes sense and I bet it works like a charm. Actually, I bet it beats the shit out of superstition crap like charms."

I spent some time working though Palmer's equations for decoction calculations and discovered, to some delight, that it would take only about 1.25 gallons of the mash to move from 151 degrees to 167 degrees (for a mash of 10 pounds). The decotion math was only approximate. But I realized that all the complication of it doesn't quite register--my nacient theory of specific heat denies that it should be so complex--so I'm going to try a decoction math simplification, if I ever get to decocting. Since the only rest the decoction will be used for is the mash out, I'm not super concerned that the calculations be precise.

Here's the simplification. If you remove a fraction of the mash equal to x/y then to add one degree to the total temperature of the mash (when you add the fraction back in) you have to increase the temperature of the faction by y/x. E.g. if you remove one fifth of the mash, you have to increase the temperature of that fraction by five degrees to net a 1 degree increase in the temperature of all of it.

I own a scale, which is pretty much all that I need to figure out how much to remove (along with the mass of the mash.)

The question, of course, is on what beer to do a decoction? Maybe on a brown ale...