This is an example of a beer brewed using the reiterated mash technique. This recipes makes for a long brewday, and there is a compromise between getting the best extract efficiency from each mash, which is important to reaching a high original gravity, and the amount of time spent. In addition, this is a challenging fermentation for the yeast. Do not skip making the yeast starter and do not forget to add yeast nutrients.
Mjollnir (Reiterated Mash)
English units
DESCRIPTION
A very strong beer that is light in color. If everything goes right, you will make a very fermentable wort on brewday and achieve a high degree of attenuation in the fermentation. This will make a beer that is full-bodied (but not overly chewy or sweet), well-balanced and very drinkable considering its strength.
INGREDIENTS (for 5 gallons)
Water
soft (<25 ppm HCO3–), distilled or RO water as base
First mash (for 6.5 gallons of brewing liquor at SG 1.040, assuming 70% extract efficiency)
7.0 lbs. 6-row pale malt
3.0 lbs. flaked maize
1/2 tsp. calcium chloride
1/2 tsp gypsum
Second mash (for an OG of 1.102 and 6 SRM, at 70% extract efficiency)
5.75 lbs. Pilsner malt
1.25 lbs. Vienna malt
3.0 lbs. flaked maize
1/2 tsp. calcium chloride
3/4 tsp gypsum
Hops (for 37 IBUs)
Magnum hops (37 IBUs)
0.75 oz (at 16% alpha acids), boiled for 75 minutes
Other
1⁄4 tsp. calcium chloride, boiled for 80 mins
1⁄2 tsp. yeast nutrients, boiled for 15 mins
1 tsp. Irish moss, boiled for 15 minutes
Yeast
Lager Option (for an FG of 1.015 and 11% ABV)
White Labs WLP833 (German Bock) yeast
(2-gallon yeast starter)
White Labs WLP885 (Zurich Lager) yeast
(for kräusen beer)
Ale Option (for an FG of 1.018 and 11% ABV)
Wyeast 1056 (American Ale), White Labs WLP001 (California Ale) or Fermentis Safale US-05 yeast
(1 gallon yeast starter or two 11.5-g packets of dried yeast)
PROCEDURE
Note: The first time you try this, don’t expect everything to work perfectly. Follow these instructions as closely as possible and take good notes for future brews.
Make yeast starter 2–3 days ahead of brewday. Mash crushed malt and flaked maize at 150 °F in 15 qts. of water. Stir in first dose of calcium (calcium chloride and gypsum) as you mash in. Stir mash every five minutes. (Add heat to keep temperature from dropping.) After 20 minutes, begin checking for conversion with an iodine test. Once test is negative (no starch indicated), or nearly so, collect 6.5 gallons of wort from grain bed. (You can do this very quickly. For example, by batch sparging.) If possible, run off wort to your hot liquor tank (HLT). If not, run off to kettle and transfer to your HLT. This wort is your brewing liquor. Heat it to 152 °F.
Quickly clean mash tun and combine 15 qts. of brewing liquor with crushed malts and flaked maize to mash at 140 °F. Add second dose of calcium. Mash for 30 minutes, then heat mash to raise temperature to 152 °F. Stir mash when heat is being applied and raise temperature by approximately 2 °F per minute. (Do not add hot water to raise temperature.) At ten minute intervals, take a reading of the density of the wort (by refractometer or hydrometer). Record time and specific gravity or °Brix. Stir the mash and add heat to maintain mash temperature as needed.
Decide when to stop mashing based on the rate of change in wort density. (Eventually, mashing for another 10 minutes will only yield a few extra “gravity points.”) Then, heat the mash to 168 °F for a mash out. Recirculate wort until it’s mostly clear and begin running wort off. Use remaining wort from first mash as sparge water (heated so that the grain bed temperature remains near 168 °F). Sparge slowly to get as many sugars from the grain bed as is possible. Do not use water to sparge at the very end. (This will dilute the wort.) Collect enough wort for a 90-minute boil.
Bring the wort to a boil, and boil for 90 minutes. Add hops with 75 minutes left in boil. If making a lager, cool the wort to 50 °F and transfer 4.5 gallons of it to a fermenter. If making an ale, cool to 68 °F and rack 5 gallons to fermenter For the lager, reserve the remaining 2 qts. of wort in sanitized container in your refrigerator. This will be your kräusen beer.
Aerate the wort thoroughly and pitch the sediment from your yeast starter. (As an option, especially if your OG is over 1.100, aerate for 1 additional minute 8 hours after pitching.) Ferment at 52 °F (lager) or 68 °F (ale) until primary fermentation ceases.
If making a lager, pour reserved wort into a 6-gallon (23 L) carboy and aerate thoroughly. Pitch Zurich lager yeast and let the fermentation begin. At high kräusen, rack fermented beer into it. Continue fermenting at 52 °F (11 °C). Once secondary fermentation slows, let temperature rise to 65 °F (18 °C) and gently swirl carboy once to rouse yeast.
If making an ale, allow the fermentation to complete and the yeast to flocculate.
Rack finished beer to a keg and force carbonate to 2.4 volumes of CO2.
If you pitched an adequate amount of yeast, Mjollnir will condition faster than you think. After a few weeks (ale) or a few months (lager), pull a small sample and evaluate. Continue sampling every few weeks. Serve when ready.
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Mjollnir (Single Reiterated Mash)
metric units
INGREDIENTS (for 19 L)
Water
soft (<25 ppm HCO3–), distilled or RO water as base
First mash (for 25 L of brewing liquor at SG 1.040)
3.2 kg 6-row pale malt
1.4 kg. flaked maize
1/2 tsp. calcium chloride
1/2 tsp gypsum
Second mash (for an OG of 1.102 and 6 SRM)
2.6 kg Pilsner malt
570 g Vienna malt
1.4 kg flaked maize
1/2 tsp. calcium chloride
3/4 tsp gypsum
Hops (for 37 IBUs)
Magnum hops (37 IBUs)
21 g (of 16% alpha acids), boiled for 75 minutes
Other
1⁄4 tsp. calcium chloride, boiled for 80 mins
1⁄2 tsp. yeast nutrients, boiled for 15 mins
1 tsp. Irish moss, boiled for 15 minutes
Yeast
Lager Option
White Labs WLP833 (German Bock) yeast
(8 L yeast starter)
White Labs WLP885 (Zurich Lager) yeast
(for kräusen beer)
Ale Option
Wyeast 1056 (American Ale), White Labs WLP001 (California Ale) or Fermentis Safale US-05 yeast
(4 L yeast starter or two 11.5-g packets of dried yeast)
PROCEDURE
Note: The first time you try this, don’t expect everything to work perfectly. Follow these instructions as closely as possible and take good notes for future brews.
Make yeast starter 2–3 days ahead of brewday. Mash crushed malt and flaked maize at 66 °C in 14 L of water. Stir in first dose of calcium (calcium chloride and gypsum) as you mash in. Stir mash every five minutes. (Add heat to keep temperature from dropping.) After 20 minutes, begin checking for conversion with an iodine test. Once test is negative (no starch indicated), or nearly so, collect 25 L of wort from grain bed. (You can do this very quickly, for example, by batch sparging.) If possible, run off wort to your hot liquor tank (HLT). If not, run off to kettle and transfer to your HLT. This wort is your brewing liquor. Heat it to 67 °C.
Quickly clean mash tun and combine 14 L of brewing liquor with crushed malts and flaked maize to mash at 60 °C. Add second dose of calcium. Mash for 30 minutes, then heat mash to raise temperature to 67 °C. Stir mash when heat is being applied and raise temperature by approximately 1 °C per minute. (Do not add hot water to raise temperature.) Take a reading of the density of the wort (by refractometer or hydrometer. Record time and specific gravity or °Brix). Stir the mash. At ten minute intervals, take refractometer or hydrometer reading and stir mash. Add heat to maintain mash temperature as needed.
Decide when to stop mashing based on the rate of change in specific gravity. Eventually, mashing for 10 more minutes will only yield a few extra “gravity points.” Then, heat mash to 76 °C for mash out. Recirculate wort until it’s mostly clear and begin running wort off. Use remaining wort from first mash as sparge water (heated so that grain bed temperature remains near 76 °C). Sparge slowly to get as many sugars from the grain bed as is possible. Do not use water to sparge at the very end. (This will dilute the wort.) Collect enough wort for a 90-minute boil.
Bring the wort to a boil, and boil for 90 minutes. Add hops with 75 minutes left in boil. Cool wort to 10 °C and transfer 17 L to fermenter if making a lager. Cool to 20 °C and rack 19 L to fermenter if making an ale. For lagers, reserve the remaining 2 L in a sanitized container in your refrigerator. This will be your kräusen beer.
Aerate wort thoroughly and pitch the sediment from your yeast starter. (As an option, especially if your OG is over 1.100, aerate for 1 more minute 8 hours after pitching.)
Ferment at 11 °C (lager) or 20 °C (ale) until fermentation ceases.
If making a lager, pour reserved wort into a 23-L carboy and aerate thoroughly. Pitch Zurich lager yeast and let fermentation begin. At high kräusen, rack fermented beer into it. Continue fermenting at 11 °C. Once secondary fermentation slows, let temperature rise to 18 °C and gently swirl carboy once to rouse yeast.
If making an ale, allow the fermentation to complete and the yeast to flocculate.
Rack finished beer to a keg and force carbonate to 2.4 volumes of CO2.
If you pitched an adequate amount of yeast, Mjollnir will condition faster than you think. After a few weeks (ale) or a few months (lager), pull a small sample and evaluate. Continue sampling every few weeks. Serve when ready.
It takes a lot of strength to battle your way through the day. Fortify yourself with Mjolnir.
First, this will be a nice project I plan to undertake in the next month or so, this looks pretty intrguing and fun quite honestly.
Not to get into water issues too deep. But the recipe has using soft water 5.2 or just go with this as is?
I know water issues are complex with many moving parts, but I’m still grappling with mashing with water too soft.
First, this will be a nice project I plan to undertake in the next month or so, this looks pretty intrguing and fun quite honestly.
Not to get into water issues too deep. But the recipe has using soft water under 25 mg HCO3 and then adding Calcium Chloride (lowers pH) and gypsum (lowers pH). My experience with water like this (very much like Portland OR water) is I get a very low pH (no buffering) with any grain bill.
Should one go ahead and use the Calcium Chloride / gypsum and adjust pH up accordingly still to get greater 5.2 or just go with this as is?
I know water issues are complex with many moving parts, but I’m still grappling with mashing with water too soft.
Glad to hear you are going to try this. It is a fun project. Let us know how it turns out.
As for water chemistry, you want the pH of both mashes to fall in the normal range, 5.2–5.6 (and optimally 5.2–5.4). If the first one is adjusted correctly, the second will just fall in line. With only pale malts and flaked maize, a little calcium shouldn’t drive the pH too low. If it does, you could adjust the pH upwards with a little calcium carbonate (or sodium carbonate). Calibrate your pH meter first, though. Pale malt and distilled water usually yields a pH of 5.6 — a little calcium shouldn’t drive it too low from that starting point.