Last Port of Call

BYOB by | Jul 2014 | Issue #90

Illustration by Ellen Crenshaw

Here’s something homebrewers can do that the pros typically can’t: fortify. Winemakers have categories of “fortified wines,” like Port, where the addition of a spirit stops fermentation short. Post addition, the alcohol level hits 16 to 19 percent—more than toxic enough to poison yeast to yield a strong, smooth and sweet eternal wine.

So why don’t pro-brewers do this? Taxes! Adding spirits changes the beer’s classification in a big way. In California for example, this means paying $3.30 per gallon instead of 20 cents.

I have done this a few times with beer, mead and cider. I’d like to say it was on purpose, but that would be a lie. Mostly, I’ve done it when a high-gravity fermentation has refused to finish. I’ll not make waste of hours of labor, so I “portify!”

Start with a strong beer with residual sweetness and a bottle of something ugly, like Diesel or Everclear. (Resist the temptation to swill it.) Before packaging, calculate how much booze you want to add, mix gently and package. To enjoy a truly potent potable, let it age for 6–24 months.

The Method: Calculate the amount of alcohol in each volume of liquid and then add them together to calculate your ethanol percentage in the new beer volume. As an example, say you want to “port” one gallon of Barleywine at 13 percent ABV and a bottle of 153-proof (76.5% ABV) grain neutral spirit. Your beer has 16.7 oz of alcohol (128 oz * 0.13 = 16.7 oz). Adding 375 mL of spirit adds 9.7 oz of ethanol (12.7 oz * 0.765 = 9.7 oz), yielding 26.4 oz (16.67 + 9.7) of ethanol in 140.7 oz  (128 + 12.7) of liquid for a new alcohol percentage of 18.8% (26.4/140.7).

For 5.5 gallons at 1.135 OG, 54 IBU, 12.6 SRM,
13% ABV (before Port) / 18–19% ABV (post addition)

Malt Bill
27.0 lb. Maris Otter Malt
1.0 lb. British Crystal 60L

Single infusion: 150°F for 60 minutes at 1.25–1.5 quarts

1.5 oz Target (pellets) | 11% AA | 60 minutes

WLP007 Dry English Ale (massive starter or starter batch)

375 mL 153-proof grain neutral spirit

When the fermentation approaches 1.035, rack the beer to secondary or keg on top of the spirit. Mix thoroughly and let age for at least 6 months.