How to interpret brewing records - part three: mashing

It seems I am continuing this series. At least for the time being, It's turning out to be less work - and less distracting - than I had feared.

Now we've looked at the ingredients, it's time to move on to the process. Starting with the most vital of them: mashing.

This is an area where there is a big variation between breweries as to what was recorded. Some record little more than the strike and tap temperatures, with nothing about how long it was mashed and left to stand.

I've chosen a Barclay Perkins log as an example because it's clear and informative.

1st column "Time of Standing"
Though it tells us a lot more than that. It also says what the operation was.

"1m 1/2 hr" first mash stood for 30 minutes
"M UM 1 1/2 hrs" underlet mash stood for 90 minutes
"2M" second mash
"S" sparge

An underlet mash is when water is added to the mash from the bottom and the rakes spun a few times to mix it thoroughly with the grain. The idea is to raise the temperature of the mash by a couple of degrees. It's a simple form of a step mash.

2nd column "L"
Standing for liquor, or water. Volumes in barrels. The underlet, the second row, was always a relatively small volume.

3rd column "H"
Standing for heat. The temperature of the water in Fahrenheit.

4th column "T"
Tap temperature in Fahrenheit. That is, the temperature of the wort when drawn off the mash tun.

5th and 6th Columns "Grist"
The quantity in quarters and the type of malt. This was necessary when a brew was split over more than one mash tun and the quantities used weren't the same in all of them.

7th column "Weight per bushel"
Multiply by 8 to get the weight of a quarter. Note that none of them - not even white malt - manages to reach the nominal weight of a quarter of 336 lbs.

The two numbers in pencil underneath the table are, I believe, the initial heats after the first infusion and the underlet.

Are you still having fun? I wonder who will get bored first, me or you?