Recipe

Gordon Strong’s Eisbock

Eisbock

(5 gallons/19 L, all-grain)
OG = 1.081  FG = 1.017
IBU = 21  SRM = 20 ABV = 8.4% (before concentration)

Ingredients
5 lbs. (2.3 kg) Pilsner malt
5 lbs. (2.3 kg) dark Munich malt
4.5 lbs. (2 kg) Munich malt
1 lb. (454 g) Carapils® malt
1 lb. (454 g) CaraMunich III malt
1 lb. (454 g) Caravienne malt
8 oz. (227 g) crystal malt (80 °L)
3.5 AAU Crystal hops (60 min.) (1 oz./28 g at 3.5% alpha acids)
3.5 AAU Tettnang hops (60 min.) (1 oz./28 g at 3.5% alpha acids)
Wyeast 2206 (Bavarian Lager) or White Labs WLP940 (Mexican Lager) yeast

Step by Step
This recipe uses reverse osmosis (RO) water. Adjust all brewing water to a pH of 5.5 using phosphoric acid. Add 1 tsp. of calcium chloride to the mash.

Mash in Pilsner and Munich malts at 152 °F (67 °C) and rest for 60 minutes. Add remaining malts, begin recirculating, and raise mash temperature to 168 °F (76 °C) by direct heat or infusion with boiling water and rest for 15 minutes. Rest at mashout temperature for 20 minutes while recirculating. Sparge slowly with 170 °F (77 °C) water, collecting 6.5 gallons (24.5 L) of wort.

Boil the wort for 90 minutes, adding hops at the times indicated in the recipe.

Chill the wort to 48 °F (9 °C), pitch the yeast, allowing temperature to rise to 50–52 °F (10–11 °C), and ferment until complete. Rack and lager for eight weeks at 32 °F (0 °C).

Rack to a clean keg and move to a temperature-controlled fermentation chamber. Lower the temperature to 28 °F (-2 °C) and check every few hours until the beer sounds slushy when gently shaking the keg. It should be ready within a day or so. Do not allow the keg to completely freeze. The goal is to transfer about 4 gallons (15 L) of beer, leaving 1 gallon (3.8 L) of ice behind.

Prepare a second clean keg. Connect the kegs using a short ‘jumper’ hose between the two beer side posts of each keg. Using a gentle pressure of CO2, push the concentrated beer from the frozen keg to the fresh keg. Watch the transfer and stop when cloudy particulates are seen in the transfer line. Lager the new keg for up to six months to smooth flavors. 

Force carbonate in the keg. I’m not sure enough viable yeast will be left to bottle condition, which is why I recommend kegging eisbock. More yeast, in addition to priming sugar, would need to be added if you chose to bottle condition.

Eisbock

(5 gallons/19 L, extract only)
OG = 1.081  FG = 1.017
IBU = 21  SRM = 20 ABV = 8.4% (before concentration)

Ingredients
8.25 lbs. (3.7 kg) Munich liquid malt extract 
3 lbs. (1.4 kg) Pilsner liquid malt extract
3.5 AAU Crystal hops (60 min.) (1 oz./28 g at 3.5% alpha acids)
3.5 AAU Tettnang hops (60 min.) (1 oz./28 g at 3.5% alpha acids)
Wyeast 2206 (Bavarian Lager) or White Labs WLP940 (Mexican Lager) yeast

Step by Step
Use 6.5 gallons (24.5 L) of water in the brew kettle; heat to 158 °F (70 °C). 

Turn off the heat. Add the malt extracts and stir thoroughly to dissolve completely. You do not want to feel liquid extract at the bottom of the kettle when stirring with your spoon. Turn the heat back on and bring to a boil. 

Boil the wort for 60 minutes, adding hops at the times indicated.

Follow the remainder of the all-grain recipe instructions.

Issue: November-December 2024

The secret of eisbock is the freeze concentration, transforming the beer from one style into another.