Ötzi’s Eisbock

(5 gallons/19 L, partial mash)

Doppelbock:

OG = 1.072 FG = 1.018 IBU = 18 SRM = 12 ABV = 7%

Eisbock: Final volume = 3.5 gallons (13 L); ABV = 10%

Ingredients

3 lbs. (1.4 kg) Munich Type II malt
8 lbs. 14 oz. (4.0 kg) Weyermann Bavarian Maibock liquid malt extract (half as late addition)
4.75 AAU Hallertau hops (60 min) (0.95 oz./27 g of 5% alpha acids)
1 AAU Hallertau Hersbrücker hops (15 min) (0.8 oz./23 g of 2.5% alpha acids)
1 tsp. Irish moss (15 mins) Wyeast 2206 (Bavarian Lager) or White Labs WLP833 (German Bock) yeast (5 qt./4.7 L starter)
0.75 cups corn sugar (for priming)

Step by Step

Steep Munich malt at 154 °F (68 °C) in 1 gallon (3.8 L) of water for 45 minutes. (Note: this is actually a small mash; follow instructions for temperature and volume.) While grains are steeping, heat 2 gallons (7.6 L) of water to a boil. Add “grain tea” to this water, along with about 2 lbs. (~1 kg) of malt extract. Boil for 60 minutes, adding hops at times specified in ingredient list. Add remaining malt extract at end of boil and let steep for 15 minutes before cooling. Ferment at 52 °F (11 °C), rack to secondary and lager at 40 °F (4.4 °C) for one month, then rack to bucket and lower temperature until ice crystals form. Remove ~1.5 gallons (5.7 L) of ice to yield 3.5 gallons (13 L) of beer at 10% ABV.