first partial mash questions

I'm attempting my first partial mash tomorrow. I am mashing 4.75 pounds of grain. I have calculated 1.5 gal of mash water and 2.5 gal of sparge water. I am going to record water loss due to grain for future brews. My main question is once I get my total wort volume of roughly 3 gal can I add 3.5 gal of water for 6.5 gal total so that I can due a full boil? Also do my numbers sound right? Thanks

bg1414 said:

I'm attempting my first partial mash tomorrow. I am mashing 4.75 pounds of grain. I have calculated 1.5 gal of mash water and 2.5 gal of sparge water. I am going to record water loss due to grain for future brews. My main question is once I get my total wort volume of roughly 3 gal can I add 3.5 gal of water for 6.5 gal total so that I can due a full boil? Also do my numbers sound right? Thanks

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For 4.75 pounds of grain, I'd use 1.5-2 quarts of water per pound of grain. So, 7-9.5 quarts of water total would be great. That's a bit more than you're planning, but the amount you're thinking of would be ok.

After the mash, I'd lift out the grainbag (if using a bag, of course!) and then pour 170 degree water over it until you get to 3 gallons or so. (You don't want to oversparge). The grain should absorb about .5 gallon of water, so you'll "lose" about that much in your calculations.

Then you can definitely add water to get up to your boil volume.

That total is for the mash water right? I think so. Sounds good. I'm using flaked oats and barley so more water may do me some good.

Last Sunday,I did a partial boil/partial mash IPA with 6lbs of grain in 2 gallons of local spring water. the mash water to grain amount was fine. Not too thin or thick. I sparge with 1.5 gallons of 165-168F water to get 3.5 gallon boil volume in my 5 gallon ss BK/MT.

ok my grain bill is below. My efficiency was calculated at 93%, is this right?!

runnings = 5.3g
gravity = 1.039

6 row = 1lb
2 row = 2lb
carapils = .25lb
roasted = .5lb
black patent = .25lb
chocolate = 1lb
crystal 80 = .75lb
flaked oats = .5lb
flacked barley = .5lb

also i mashed at 154 and used 184 F sparge water which took grain to 163 degrees

if I calculate based on max ppg x lbs / gal collected for all grain I get 93%. If I take the gravity x 5.3g and divide by grain used (7 lb) I get 29.5 or 30ppg. According to Palmer I divide 30 by 37? and get 81% so which is right?

one more thing. just finished the brew. My o.g. with 5 gallons in fermenter was 1.052. my target was 1.062. After the mash I topped off kettle to 6.5 gal and used 2 pounds of dme. I'm not sure why I ended up 10 points off. Any advice??

anyone? I also think if I would have added another .12 to .25 lb of dme I would have hit my target gravity of 1.062

What did you boil off to volume-wise? I got half gallon boil off from 3.5 gallons boil volume myself. The OG was to be between 1.056-1.075. My OG was 1.060 for the recipe I designed in BS2.

I collected 5.3 gallons and topped off to 6.5 gal for boil. Final in carboy was 5 gal.