High Gravity Brewing
Wednesday, June 29th, 2011There were several great topics covered at NHC this year. One of my favorites was “High Gravity Brewing” put on by Patrick Rue, owner of The Bruery in Orange County, Ca. For purposes of the talk, Patrick defined “high gravity” as anything around 15% ABV or higher. I’m not normally one to brew high gravity ales. This is not because I don’t like them, but rather due to the long aging time and how little you can drink before you’re on the floor. Having said that, I find big beers enjoyable especially because one can add many more unusual flavor items (think sage, basil or other big spices) along with long barrel aging that would simply overpower a session beer. Since you’re dealing with such a large alcohol content, large amounts of malt and hop additions are a must to balance the beer. Bolder flavors, bolder hop charges – it starts to feel like an expanded pallet with which to create some very interesting, and ultimately very drinkable brews.
Although you’re free to do so, one should not simply create a booze bomb that will knock your friends over inside of 16 ounces. While that’s all a bunch of giggles once, you’re going to have 5 gallons of this stuff to unload, you may as well enjoy it on a more complex level. But before we get to flavors, let’s talk about the how. You’re going to need a big yeast starter in order to get the yeast healthy enough to tackle all the fermentables. Patrick is a big fan of White Labs 570, 550 and even good ‘ol 001 for the job. WL-1388 – Belgian Strong Ale is one of my favorites for really adding some great yeast character without being dominant. For 5 gallons, you’ll probably want around a full liter of starter that has been on the stir plate for a good 4 days or so. Pitching a fat and happy colony is the only way to get this done. You may still need to pitch another round of yeast about 3/4 of the way through just to get the gravity down to where you want it. Otherwise you’ll have alcoholic pancake syrup. No kidding. Start low on the fermentation temperature (60F – 65F) until it begins to slow way down, then allow it to naturally rise to around 70F for the finish. Due to the sort time at the higher temp, the risk of too much phenol or fusel flavors is minimal. A small dose of O2 before pitching or re-pitching is also a good nudge for the yeast to get rolling. A blow-off tube is recommended over an airlock as this will get rocking.
Moving on to the grain bill, you’re going to want up to 15% of dextrin malts (crystal and caramel) to get to the desired gravity, but don’t worry too much about over sweet beer because if you managed the yeast right, you’ll burn through much of that sugar without too much issue. From there, you can go anywhere you would with a full-bodied ale, just more of it. Low mash temperature with a longer rest is another trick to maximizing your fermentable sugars (140F – 150F), remember you’re shooting for a SG of 1.100 or there about, with a FG of 1007 or so. Using mono saccharides like dextrose, honey, or agave is great, but don’t let it exceed 25% of the fermentables. Doing so can cause your yeast to bomb out early because they get used to munching down simple sugars and will no longer want to work on maltose sugars. Dough in your mash at around 1.6 to 2 quarts/lbs of grain, which is higher than usual, but you’re gunning to get much of your wort out of that first infusion (Not a bad idea to do a second runnings for a small beer off of whats left). You’re looking at a 90 minute boil to develop more malt character in the wort.
Hops should come in at no more than 50 IBUs. With the heavy grain bill, you’ll still need an extraordinary amount to get there. These beers are all about balance and character. Attempting an Imperial IPA at these levels may result in tears. Though I doubt that will stop anyone from trying it! With strong ales, you want that initial hint of sweetness to give way quickly to the spicy alcohol notes and adjuncts, then finish very dry.
Finally, these beers need age to gain their true potential. 10 to 18 months is a common range. Barrel aging provides a slight micro aeration which can be very desirable in a beer that will sit this long. Barring that, I’d say adding lots of oak chips to your aging vessel would be a nice flavor enhancement.
I’m going to try brewing up this recipe that I whipped up by cobbling together some ideas that I liked in a few strong Belgian ales that I found. I’ll post some notes when it’s finally done… many moons from now.