After stepping up my yeast starter for two weeks, I finally got to arrange a brew day for today. Starter off stellar… forgot this was the weekend to change the clocks ahead, so instead of mashing in at 8 am, it was 9. Mash temp came in a little lower than I should have done. 150° turned out to be 148°. We’ll see how dry this finishes in the end to know if this was too low or not.
I aimed to get 8 gallons of runnings, expecting to loose a lot more in boil off than I normally do, due to the fact that I was going to boil for 90 minutes vs the typical 60. Common rule is that with a large amount of pilsner malt in the grist, a longer boil is needed to get rid of DMS (Dimethyl sulfide). This recipe was 100% pils malt, so a 90 min boil was necessary. Longer boil, more volume lost to evaporation. I’ve also lost more to boil off in the cold winter temps, so I was sure I needed as much as I could to end up with the 5.5 gallons in the carboy.
When I collected my runnings, I had almost 8 gallons. I was shocked to find my preboil gravity was 1.048, instead of the 1.038 my software had calculated. I typically get 70% efficiency from my cooler mash tun. The preboil gravity reading (taken twice to confirm) suggested 82% efficiency. I believe the difference may have had to do with the crush of my grain at Border Brew Supply where I get my supplies. Their grain mill was acting up, and we adjusted it while I was there. Could be it provided a finer crush of my grain which would lead to a higher efficiency to some degree.
I was careful not to boil to vigorously, and in the end, my gravity post boil was 1.056. Original recipe was calling for 1.051, but with the higher efficiency, and my projected boil off, I expected an OG of 1.059. So, my boil off rate was not as high as I anticipated either. Likely the controlled low boil and the higher outdoors temp than the last brew (morning started at 25° but was in the 40s by boil time, where the previous brew was sub freezing temps).
I poured the chilled wort from the pot into a brew bucket, churning and aerating. I then used a racking cane to transfer from the bucket into the glass carboy. By the time I stopped, what was left in the bucket was heavy with sediment. The carboy had less than the desired total volume in it, and when the wort settled, I could tell I was going to lose a lot more volume due to the amount of sediment at the bottom of the carboy. Given I had a higher OG than planned already, I decided to add about a half gallon of (boiled and cooled) water to the carboy before pitching my yeast. This way I know I should get my 5 gallons of final beer and it will be closer to the starting gravity I planned on.
Yeast: Wyeast 2206 Bavarian Lager yeast. Mr Malty calculator suggested I needed a 3+ liter starter. I built up a starter, first with 1.5L of wort (form DME), and stepped it up twice over two weeks resulting in an approximate 3L starter. I chilled the starter, decanted the excess liquid, and pitched the yeast with the carboy at about 56°. Put the carboy back into the fridge and will see what temp the fridge can hold it at. I would ideally like it at 48-50, but the fridge may not be able to keep the temp higher than 41° or so… if that’s the case, I will be putting the carboy into a bucket of water on the basement cement floor, and hope the ambient temp will be enough.
Obviously, more to come as the brewday is only part of the process, especially with a lager.