I'm brewing up some "small" batches of beer now so that I can experiment with a wider range of styles with less cost and less beer to bottle and keep around. Yesterday was the first attempt at this; Liz and I brewed up two Belgian beers - a Witbier (white beer) and a Belgian Dark Strong. Both beers are ales and have the same fermentation profile which allows me to place them both in the fermenter and ferment at the same temps/schedule.
|Witbier on the left, Dark Strong on the right.|
When boiling smaller volumes of wort, the boil off rate increases significantly, which results in increased a higher Original Gravity and a lower volume of finished wort in the fermenter. Next time I'll need to raise my batch from 3 gallons to 3 1/2 and increase my brewhouse efficiency rate. The Witbier ended up with 90% brewhouse efficiency (I had figured 75%), but yielded just over 2 gallons.
We also step mashed yesterday for the first time. The Witbier has a high amount of wheat (35%) and oats 8% which would create a wort that is highly viscous and likely impossible to sparge. To avoid a potential stuck mash, we performed a protein rest at 130F for 15 minutes before raising the temperature to 150F. I started the mash in a kettle by heating water to 145F and doughing in to hit my target of 127F (was high though at 130F). After letting it rest at that temp, I turned the heat on low and attempted to slowly raise the temperature to about 155F. I wanted to over heat slightly so when I transferred to the mash tun cooler, I'd hit 153. I ended up losing 5 degrees when I transferred so, I'll have to plan for that next time.
The problem that occurred is I didn't realize how fast the mash temperature could rise with such a small mash. I had the heat on low and was stirring constantly to avoid scorching the grains. After a few minutes, I checked the temperature and I had hit 170F! I quickly filled a pitcher of water with 120 degree water (from my tankless heater) and poured a half gallon in. That was enough to lower the temp down to 140. I then slowly raised it to 155F and then poured into the mash tun. I was concerned I may have stopped the alpha amylase enzyme activity but it was only at that temp for about 2 minutes. My efficiency was quite high, so I think I'm ok. It also didn't help that the Dark Strong was beginning to boil (and boil over) at the same time I was trying to raise the mash temp!