On Tuesday, I made my second attempt at brewing a "super lager" (like the one I blogged about in March) by using wort from one mash as mash liquor and sparge water for another.
I reviewed my notes from the last big brew, thought about it for a little while and made a few changes. For this beer, I made the weight of the two grain bills equal. I also took a "no sparge" approach to the mashing. I added my full pre-boil volume of water to the first mash, ran it off and used this wort as mash liquor for a second "no sparge" mash. (I had to make a few minor volume corrections on the fly as the grains in each mash absorbed some liquid.)
The big advantages of this method are you can collect high gravity wort, all from grains, and not have to boil forever to get a very high gravity wort. (I hit the same original gravity on this beer as with my first try, but I only boiled the wort for one hour, as opposed to the 2.5 hours it took before.) Shorter boil times means you can make lighter colored beers, or at least control the color of your beer more through ingredient choice than color pickup during the boil. The method is also fairly efficient in terms of how much extract you get from your grains (unlike some other all-grain methods of big beer production). The downside, of course, is that it takes time to do an extra mash in a brew session (but not really that much, as I found.)
I pitched the wort with German Bock Yeast (White Labs WLP833), aerated it heavily with oxygen and it's fermenting away right now. (Last time I used an Octoberfest strain and it didn't get very far in the primary fermentation.) As I did last time, I reserved 1 L of wort for kräusen, to pitch with White Labs Zurich Lager yeast (WLP885) and add to the main batch once primary fermentation winds down....