If anybody is bored and doesn’t mind reading, tell me what you think of my brewing method described below. The main reason for doing a 4 gallon boil is so I don’t have to buy wort chillers and a big new brew pot. When I mash I only get 61% efficiency since I’m only collecting 4 gallons. I know I leave some fermentables behind but that’s the trade off.
Converting an All Grain recipe to my 4 gallon boil method
Recipe = American Pale Ale / starting gravity of 1.056
American 2 Row (potential = 1.036) 8 pounds
Vienna (potential = 1.036) 2 pounds
Crystal 10 (potential = 1.035) .5 pounds
Gravity Units for normal all grain full boil method
(potential)x(lb’s)x(efficiency)
American 2 Row 36 x 8 = 288 x 75% = 216
Vienna 36 x 2 = 72 x 75% = 54
Crystal 35 x .5 = 17.5 x 75% = 13
Total Gravity Units = 283 / 5 Gallons = 1.056
4 Gallon Boil method
I did some thinking and realized that I simply can’t mash the same grains and then top off with a little DME to get back to the right amount of GU’s. Doing that would throw off the recipe because I would end up using more base malts than what the recipe called for. So I do the following:
The first thing to do is tweak the amount of adjunct grain until get back to our required gravity units:
(potential)x(lb’s)x(efficiency)
Vienna 36 x 2 = 72 x 75% = 54 (goal)
Vienna 36 x 2 = 72 x 61% = 44 (abviously low)
Vienna 36 x 3 = 108 x 61% = 67 (too high)
Vienna 36 x 2.5 = 90 x 61% = 55 (perfect)
Do the same for the crystal
Crystal 35 x .75 = 26 x 61% = 16 ( a little high but it will do)
Now we need to figure out the 2 row gravity units, Originally we were using 10.5 lbs of grain, 8 of which was 2 row. We added some weight to the adjuct grain to keep our gravity units up. We need to subtract the total adjuct graint weight from the original weight, this will give us the amount of 2 row to use. This needs to be done so we stay at 10.5 lb’s of grain and 4 gallons of collected wort.
Vienna = 2.5
Crystal = .75
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3.25
Total weight = 10.5
Adjunct weight = 3.25
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7.25 (total amount of 2 row to use)
Now we can figure out the gravity units we’ll get from our American 2 Row
American 2 Row 36 x 7.25 = 288 x 61% = 159
Now lets total up the gravity units:
American 2 Row 36 x 7.25 = 288 x 61% = 159
Vienna 36 x 2.5 = 90 x 61% = 55
Crystal 35 x .75 = 26 x 61% = 16
=======
Total = 230
Subtract that from our original estimated gravity units
283 – 230 = 53
We need to add enough DME to get 53 gravity units so we hit our 283 goal. Since we know that DME has a potential of 44, all we need to do is divide the GU’s we need by 44 to give us the pounds of DME we need.
53 / 44 = 1.2 ( we could add 1 lb of DME to get us close enough, it’s not rocket science)
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I can’t wait.
