Wednesday, October 26, 2011
Brewday - Oatmeal Stout
The cold-steeping method I used requires a 24 hour steep at room temperature so I made this several days before I brewed. I was intrigued that, similar to crystal malts, it is not necessary to mash dark malts, and sure enough when I tested the gravity on the steep it was 1.047, barely below my overall target gravity of 1.055. No enzyme activity necessary, just steeped and ready to go.
The brewday itself involved more steps than I was used to, and this led to a more challenging and incredibly fun brew. I started by using reverse osmosis water from the supermarket as I have read about the bad effects of chlorine and chloramines that are present in our tapwater. I then added gypsum to provide some calcium, which would normally be present in our tapwater, but is stripped out by the RO process. Small amounts of calcium is apparently important for various aspects of mash chemistry.
The mash was an increased challenge as I had to account for the later addition of the steeped grains as well as the mashout addition. A mashout is not something I've ever really bothered with. The idea is to heat the mash to the point that the enzymes in the malt become denatured, fixing the ration of fermentables to non-fermntables in the wort. It also has the added benefit of raising the temperature for effective sparging right from the beginning of the sparge. Since I wanted to try to improve my efficiency and also keep a high amount of unfermentables in the wort for added body this seemed the perfect time to try it. I wasn't able to raise the temp as much as I hoped, but it was a good learning experience for next time and my overall efficiency was largely improved.
I even got the chance to try out a friend's refractometer, a device that can read gravity with only a few drops of sample, and even account for temperature without annoying conversion calculators. Its was incredibly easy to use and tested against my hydrometer in both pre and post-boil samples the reading were within .001. The only problem I had was the occasional highly innaccurate reading, possibly caused by some water getting into the sample. It is also apparently quite difficult to use on beer once fermentation has begun, so for these reasons I would not abandon the hydrometer completely, but rather use the two in conjunction. I'm definitely getting one of my own just for its ease of use and for the minuscule samples required to operate it.
This brew went great with only some minor hiccups and I'm now really looking forward to refining some of what I learned and applying it to a Russian Imperial Stout. Until then...