Howdy GF friends....
I'd like to see if we can revisit the topic of mash water / sparge water calculations. It feels like its been awhile since we've seen updated comments about the GF water calculators online.
I wont try to bore you, but its probably best to give you all this good info if I am asking for your help:
- I have ONLY used the GF water calculators
- ******** Interesting observation - after creating recipe at GF.com, then hitting the "brew recipe button", the mash volume stays the same BUT the sparge volume slightly increases (example from 2.68 gal to 2.94 gal)
- Last 2 batches, I entered 5 gal for "batch size" which I am told is the target volume you expect to yield in fermenter after mashing, sparging, boiling, chilling, etc
- Last 2 batches, both times I yielded 6 gal in the fermentor:
- Previous batch I came in low on target OG (1050 vs. 1060)
- Last batch brewed on Sunday I came in low on target OG, but arrived closer to target (1055 vs 1059)
Sunday Brew Day: 75% Efficiency ---> Estimated Losses = - 0.8 gal boil off @ 5,280 feet; -0.12 gal/lb grain absorb
-
Grains = 10.75 lbs, milled onsite at same HBS, same mill, same mill settings
- Mash H20 per GF =
4.40 gal
- Sparge H20 per GF "recipe creator" =
2.68 gal (GF recipe creator,
this is the sparge water volume I used)
- Sparge H20 per GF "brew session" = 2.94 gal
(why the adjustment ???)
-
Mash steps - Protein 122F @ 30 min; Beta 147F @ 50 min; Mash Out 168F @ 10 min
**** NOTE: stirring the mash ~ 20 min or so causes the GF temp probe to spike up (confirmed temp spikes with external thermometer)
-
Sparging = Lifted grain basket, let it completely sit & drain
BEFORE adding sparge water. GENTLY pressed down top mash plate to sit on top of grain bed. Using small quart size pitcher, poured 2.68 gal slowly on top of grain bed.
-
Boil = 60 min, consistent rolling boil throughout
Total H20 needed per GF =
7.08 gal
- H20 in Boil Kettle after 90 min mash =
6.90 gal
(Pre-Sparge Gravity = 1.062)
- H20 in Boiler after 60 min boil (pre-whirlpool) =
6.47 gal
(whirlpool, chill, rack to fermenter)
- H20 in Fermenter =
6.08 gal
(OG - 1.055)
Conclusion: It appears that I am getting enough sugar units out of the grain, but adding too much water to hit batch size. If I use less water to sparge will reduce sugar units, but will increase OG... The last gallon of sparge water added very little sugar to the boil wort.
Since gravity is a ratio of sugar to water... I have enough sugar but too much water????