Greetings and thanks in advance for any help.

Planning my first all grain brew. I will be brewing a 5 gal. batch of Caribou Slobber Brown Ale.

I have a question about my total volume of water. Going by the basic Northern all grain instructions, it looks like I’m going to use 10 gallons of water. Even with grain absorption and boil off, seems like to much.

Receipt has 10.5 lbs. of grain.

Mash calls for 1.25 to 1.5 qts. of water for every pound of grain, which equals 3.5 gallons for mashing.

Boil 1.5 gallons of water for the mash-out.

Sparge calls for 2 quarts of water for every pound of grain, which equals 5 gallons of water.

3.5 + 1.5 + 5 equals 10 gallons

I believe I would need to start the boil with 6 to 6.5 gallons of water. It appears I need to reduce total water to something closer to 8 gallons. But where do I reduce? Mash or Sparge?

A second question: Can you really have a general rule for mash and sparge water? If you always used the same amount of water to grain ratio, wouldn’t you always end up with the same gravity of beer?

Thanks, Dan