Question about my Altbier recipe and water to grain ratio

So I would like to make my next batch an Altbier and I have this recipe, but I am confused about the mash portion that talks about water to grain ratio. It starts with a 1/1 ratio and then steps it up through the other temperatures. Is this recipe assuming that I am ADDING water to achieve those temps because I will be using a heat exchanger and not adding water. If that is the case when should I change the grain ratio, and by how much?

(PS yes I am looking at changing that protein rest to the low 130s)


6lbs German Pils Malt
2lbs Munich
1.25 lbs CaraMUnich III

80min boil 6.4AAU Spalt
60min addition 1.5 AAU Saaz
5min adition 3.1 AAU Saaz

Mash grains in one quart of water per pound of malt at 100° F for 15 minutes.
Raise to 122° F for 20 minutes, then do a conversion rest at 150° F for 60 minutes.
Mash out at 170° F. Sparge with 170° water. Ferment at 60° to 64° F
for six days. Rack to secondary for three weeks at 32° to 40° F.

Thanks for the help everyone

I don't see it telling you to change water ratio?

phoenixs4r said:

I don't see it telling you to change water ratio?

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At the same time, 1 qt/lb is pretty low.

Yea exactly that's what I was thinking. The recipe was kinda thrown together when I found it so I was guessing they wanted me to raise the temp by adding water.

What would be the result if I did keep it at 1/1 for the entire mash?

If you can, you can mash with whatever amount you want( I would probably go higher than that though), and use decoctions to step up the mash

I used Kaiser's instructions for a double decoction mash the last time I made an alt and it turned out fantastic
http://braukaiser.com/wiki/index.php?title=Decoction_Mashing

when I plug in double decoction mash in beersmith it recommends using a ratio of 2qt/lb

There are theories that a lower water ratio could possibly lengthen the time to convert. I don't have any sources to prove that though.

I have no idea what it does when decoctions are involved.

Ok so maybe just bump the ratio up a bit to help conversion since I do have my system set up for HERMS so i rather not go the decoction way on the recipe.

Zakit24 said:

Ok so maybe just bump the ratio up a bit to help conversion since I do have my system set up for HERMS so i rather not go the decoction way on the recipe.

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Oh. I've don't have a herms but I've heard you really need a thin mash to make them work. So I'd imagine yes, young would need to bump up the ratio.