I'm using this infusion calculator to determine how much and what the water temperature should be when adding water to my mash tun. A recipe I'm following calls for a protein rest at 122 degrees F for 30 minutes followed by 60 minutes at 155 degrees.

I've entered the first protein rest step using 0.75 qt per pound ratio (I'm aiming for 1.25 per pound in the end). There are 11.5 pounds of grains, so I'm coming up with an infusion temperature of 135 degrees and 8.6 qt of water.

For the second step, I'm assuming we'll lose about two degrees, so my desired mash temperature is 155 degrees, starting temperature is 120 degrees and I have no idea what the infusion water temperature is. Shouldn't the calculator tell me?

What is the calculator asking me? I'm very confused right now!

1 Answer 1


I just ran the calculator doing what you propose. Its simply asking you, what is the temp of the water you plan to infuse with. In order to hit 1.25qt/lb I had to tell it I was going to use 212F (boiling) water. And it then said I would need 6.3qts of 212F to get there. (I didn't account for your 2degree loss though).

If you wanted to use 190F water you're final ratio would be bigger than that, but not much. I wouldn't worry about it. In fact, I normally mash at 1.5qt/lb.

Using boiling water for the infusion is pretty normal, so don't worry about that. Just pour it in and stir it up fast.

  • Thank you very much! That's what I was suspecting, but I didn't want to screw up another batch.
    – senfo
    Nov 11, 2012 at 5:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.