Question about calculating necessary amounts of water

Since I have started all grain, I feel very comfortable with the process. However, I feel like I need to better understand how much water I need. I realized this when using the Recipator this evening and thinking about the portion of the spreadsheet that asks for pre-boil volume, etc.

Previously, I have always followed specific recipe directions to determine the amount of water that I need for mash/sparge/etc. Now that I have created my own recipe (hopefully), how should I go about determining amounts of water needed. For instance,

1. How many gallons of water per pound of malt should I use for the mash?
2. How many gallons of water will the grain absorb during mash and sparge?
3. How can I calculate the amount of water that will evaporate in my 60 minute boils?

If I am right, having answers to these questions should be enough so that a brewer can ensure that he has 5 gallons (or very near it) at the end of the boil.

Promash will do all that for you. Thr trial version is very handy and fully functional, the only thing is that it puts a limit on saves and won't let you print. Super handy for building recipes even if you don't shell-out for it.

I batch sparge and use 1.2 quarts per pound for the mash. All that I read said to figure .1 quarts per pound for grain absorbtion. As far as evaporation I think it would have to be calculated for your individual system. Promash defaults at 15%. You may also have some deadspace in the mash tun and boil kettle that has to be factored into your water calculations as well.

Chairman Cheyco said:

Promash will do all that for you. Thr trial version is very handy and fully functional, the only thing is that it puts a limit on saves and won't let you print. Super handy for building recipes even if you don't shell-out for it.

Click to expand...

Just got Promash yesterday. Be sure to go to the help and do the Tutorials as they answered a bunch of questions I had when I started to play around it them.

For the #1 - I think it depends on your equipment, beer style and your preferences, it could be somewhere in the range between 1-2 quarts/pound. Lighter beer - higher the ratio. #2 - 10 pounds of grain will hold 2 gallons of water. #3 - again, it will depend on your equipment. In my boil it would be little <1 gallon/hour