When brewing at home, I am very limited due to the small amount of open space in my apartment, and zero outdoor space to set up a propane burner. Therefore, my brewing set up is somewhat minimal. I use two pots, one to hold my strike water (which then acts as my boil kettle) and another for sparge water, and a 10 gallon cooler w/ false bottom as my mash tun. I have an 8 gallon pot and a 5 gallon pot, but because I am only able to get about 4.5 gallons up to a nice, rolling boil on my stove top, I do 3-3.5 gallon batches that I boil in the 5 gallon pot. I’ve been doing it this way for years and have my system very well dialed in and am quite happy with the beers I’m able to produce this way.
I prefer to brew low – medium gravity beers, but occasionally I will brew a high gravity beer. After pondering what to brew next, I realized that I’ve never brewed an English Barleywine. I decided to go for it and did some reading on the style and how it is brewed. I found that, traditionally, these beers were brewed not much differently than standard English pale ales, but with a much longer boil time (usually around 3-4 hours). Although it sounded like a long brew day, I decided to go for it. However, on my system, if I were to boil my wort for 3-4 hours, I would only be left with a gallon or so in my 5 gallon pot. Such a long brew day with only 1 gallon to show for it? No thank you. I decided to get a little creative in order to get a better yield.
I started the brew day as normal by mashing in about 14 pounds of grain (remember, this is a 3 gallon batch) and hit my mash temp of 151F. I let the mash rest for about 90 minutes as I ran some errands. A slightly extended mash time helps to ensure as many sugars are converted as possible. I’ve noticed on my system that I lose some efficiency when brewing higher gravity beers (and I think this is typical of most systems). Typically around 5-8% efficiency loss, so I adjusted my Brewhouse efficiency from 68% to 60% when calculating my grain bill. I mashed a little bit on the thin side to ensure my first runnings would be about 4 gallons into the boil kettle. After recirculating and collecting my first runnings, I had about 4 gallons of thick, syrupy first runnings wort at around 1.084 SG. I started heating the first runnings as I continued sparging the grain bed into my other brew pot. By the time my first runnings had been boiling for about 30 minutes, I had another 3 gallons or so of second runnings wort (around 1.030 SG) that I began to bring to a boil on another burner on my stove.
What I was doing was basically a “parti-gyle” brew, but instead of getting one big beer and one small beer, I decided to use the small beer to “top up” the boil on the big beer as it boiled and just go “all in” on the big beer. As the main beer boiled and concentrated, I continued to feed it more of the boiling second runnings to keep the volume up, but still continually concentrating the first runnings. After topping up and boiling off for about 4 hours, I decided to call it good. I still had a little second runnings left in the pot, so I could’ve continued to boil, but I figured 4 hours was long enough (plus, I was getting tired and still had to clean up). I transferred about 3.5 gallons into my fermenter, took an OG reading (1.102, an increase of almost 20 points from the pre-boil gravity), oxygenated the wort and pitched a big, healthy looking starter (OYL-006). I was pretty happy with this OG reading considering it comes out to almost 65% efficiency on my system, which is the highest I’ve gotten on a high gravity brew.
The next morning, I oxygenated the wort one more time before leaving for work. A second dose of oxygen about 12 hours after pitching can be beneficial for very high gravity beers as the yeast typically needs more oxygen than it gets on the first dose. I came home that night to a very violent (or happy?) fermentation. Luckily, my fermenter was in my Cool Brewing Fermentation Cooler which not only keeps the fermentation temp a few degrees cooler than my apartment, but also contains quite a big mess. I cleaned it up, switched out the airlock and let it continue to rip (had to keep an eye on the airlock to make sure it didn’t clog for the first few days). After a week or so, the beer seemed to have fermented out completely. At time of writing this, it is still in primary right around the 4 week mark. I plan to move it to a secondary vessel very soon and allow it to age at least another 2-3 months before bottling (adding fresh yeast at bottling).
If you have a larger set up (a larger boil pot to hold an extra 4 gallons or so of wort pre-boil) and higher BTU output on your burner, then this method may not make sense for you. However, the extended boil is known to enhance the mouthfeel and viscosity of your wort (and of course increase the gravity), which many styles can benefit from, and this was the only way I could utilize an extended boil without sacrificing a large percentage of my yield. It seemed to work on my system pretty well, and I am happy with how it is going so far. Stay tuned for tasting notes some time in the next few months.