My name’s Michael. I’m a homebrewer originally from Austin but living far, far away. I hear you a bunch on Basic Brewing Radio and I read your article “Expand Your Output” and I had a quick question for the expert in diluting high gravity beers.
I brew BIAB and I made a “super saison” and I didn’t get too much wort (only 13 L) because I made a smaller beer out of the second runnings.
I pitched a healthy amount of WLP565 (farmed from a previous batch) and fermented fairly warm until it attenuated the crap out of this beer, with apparent ABV of over 11%. (OG 1.091. FG 1.006.)
I’d like to boil my priming sugar in 3 L of water, so I can bring my ABV down to the target 9%.
The beer has ~50 IBUs and will need at least 3 months of conditioning.
Will I ruin this beer by diluting it?
— Michael Maze
When you dilute a beer at packaging, you dilute every aspect of it — malt flavor, hop bitterness, hop flavor, hop aroma, yeast-derived aromas, body . . . everything. This practice is called high-gravity brewing or sometimes blending for volume. Most American-style Pilsners are made this way. A stronger version of the beer is brewed (from an OG 16 °Plato/1.064 wort) and then diluted to working strength (around a virtual OG of 11 °Plato/1.044) with de-aerated water before packaging.
In diluting your beer, you may improve some aspects of it. For example, you’re shooting for lower alcohol and dilution will assuredly accomplish that.
I’m guessing that this beer is pretty estery given the high original gravity, high-temperature fermentation and yeast strain. Taking the yeast-derived aromas down a notch might also be a good thing. Your IBUs would also drop to 41, which shouldn’t be much of a problem in a saison.
However, I’m wondering if the beer might end up too dry. It’s already at SG 1.006. Your planned dilution would bring this down to (just shy of) 1.005. Diluting it may make it seem like “rocket fuel” — all alcohol (even at 9%) and no body.
The good news is you can try the dilution ahead of time. Take a small sample from the fermenter and make your proposed dilution and taste it. Use highly-carbonated water (or Michelob Ultra or similar ultra-low-flavored, super-fizzy beer) as the water. You could even make a series of dilutions and see if you like any.
Normally, when brewers use this technique, they’ve planned ahead so everything in their beer is above their target. Then, the blending water just brings everything down to the levels they want. Using this technique in an unplanned fashion has a much lower success rate. You’re likely to dilute one or more aspects of the beer below a reasonable level.
So, you can try some test dilutions, and maybe you’ll find a degree of dilution you like. But I’d hazard a guess that letting the beer condition and leaving it as is would be your best bet.
This is the first installment of what we hope to be an ongoing series of posts answering homebrewer questions. If you have a question, email me at email@example.com. I’ll try to get a quick answer to you in a couple days, and after that the answer may appear in this column.