Mash Out! Reiterated Mashing

It’s hard to believe that it’s already July and the craziness that is 2020 is half over.

That being said, while you may be currently in the mood for a fruited kettle sour or a juicy NEIPA, now is the time to brew something big and boozy. Something for the colder months that will warm you from the inside out, something that will benefit from some aging. A barley wine or an imperial stout would do the trick.

“But Mike,” you may say, “my brewing setup only allows me to brew five gallon batches of moderate strength ales and/or lagers!”. In response to this, I only have two words: reiterated mashing.

Reiterated mashing is a technique that is very useful in a situation where your brewing setup has a limited amount of space for your grain bill. I brew on a Robobrew and I always brew five gallon batches. I could certainly brew smaller batches but where’s the fun in that? I want to brew something big and I want five gallons of it. Here’s how you can do it too!

The idea behind reiterated mashing is to split your grain bill in half and to mash half of the grain, sparge, mash the second half of the grain in the wort produced from your first mash then sparge until you reach your preboil volume. Continue with the boil as usual.

I recently brewed a barley wine using this technique. While you may lose some efficiency and it certainly makes for a lengthy brew day, it yields good results. 

Here’s the recipe I used:

Gil’s Birthday Barley Wine: An American Barley Wine (5 gallon batch)

87.8% Maker’s Malt Premium Pale Malt
2.4% Crystal 30 malt
2.4% Carared malt
1.2% Crystal 60 malt
0.6% Crystal 120 malt
0.6% Special B malt
4.9% Honey

0.33 oz/gallon (65 IBUs) of Columbus at 60 mins
0.16 oz/gallon (11 IBUs) of Cascade at 60 mins
0.16 oz/gallon (10 IBUs)  of Centennial at 15 mins
0.16 ox/gallon (2 IBUs) of Cascade at 5 mins
0.2 oz/gallon Cascade in the whirlpool
0.2 oz/gallon Centennial in the whirlpool

US-05 yeast

0.4 oz/gallon Cascade dry hop

0.2 oz/gallon Centennial dry hop

For a five gallon batch, I took 9.75 lbs of the malt and mashed it for 60 mins using 15 litres of water at 156°F. I then lifted my grain basket, drained the wort, and sparged the grain using 8 litres of water. I then heated the wort to 156°F, cleaned out the malt pipe on the Robobrew and mashed the second half of the grain in the wort from the first half. After an hour, I lifted the malt pipe, let it drain and sparged the grain just until I had my preboil volume of 24.43 litres of water. I then followed standard practice of boiling and cooling.

After transferring to a glass carboy, I pitched some US-05 and the beer is happily fermenting away. As with all high gravity beers, a yeast starter is recommended to make sure your yeast is happy and healthy. 

Have fun and happy brewing! 

P.S. As always: comments, questions and concerns can be sent to mike@canadahomebrews.ca. I’d love to hear your suggestions for next month’s Mash Out column!

5 thoughts on “Mash Out! Reiterated Mashing

  1. My last two brew on my 30l Grainfather both was high gravity beers (a barleywine and an impy stout).Mashed 6.1kg grain in one go for the barleywine,it’s conditioning already,11.4% abv,but tried for the first time reiterated mash with my impy,7.9 kg malt,so splitted in half.
    In both case i’ve reached my numbers (2-4 point difference).The stout fermenting now,10.8% abv atm.
    It was a good experiment,but not convinced me 100% about the neccesarity of the way longer brewday in my case.
    However I brew only 10 liter batches,I like to experiment a lot.Seems more useful if you brew full size batches tho.
    Sry for my English,not my native language.

  2. Hey, Mike,

    I have a real soft spot for barleywines. This recipe looks awesome and, as you noted, very timely for the long, dark winter ahead… (Although not really very long or dark where I am in southern Virginia.) I’m a huge fan of special B and honey so this hits all the notes.

    A few questions: What were you shooting for OG-wise? Another question about the honey. You responded in an earlier post that the honey portion of the bill is 4.9% liquid honey. Is that 4.9% of the MASS of the grain bill or 4.9% of the total points of the grain bill?

    In any event, it’s next on my brew calendar!

    1. Thanks, Lee! The OG we were shooting for was 1.097 and the honey is 4.9% of the total weight of the grain bill. Thanks for tuning in!

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