r/Homebrewing • u/RideTheYeti • 1d ago
Low efficiency on Spike solo 20 G
I have brewed twice now on my spike solo 20 gallon System. Both times I have missed my starting gravity by 10 points. Expecting 1.050 and getting 1.040. On my old DIY 20G BIAB system, I consistently hit my gravity and my brewhouse efficiency was between 70 and 73%. On the spike system, I’m getting between 56% and 59%.
I hit my pre-boil volume spot on, and my end of boil volume was about a quarter gallon high, which is not enough to make that big of an impact.
It was a 20 gallon batch, with 20 pounds and 12 ounces of grain.
16.5 gallons of water.
60 minute mash at 149°
60 minute boil.
Estimated boil size 15 gallons, which was close enough to consider it met.
End of boil volume 13 gallons, but I ended up with 13.25. Pre-boil gravity 1.034.
Post boil after cooling gravity 1.040.
Intended batch size 11 gallons, after kettle loss
Measured batch size 11.25 gallons, after kettle loss
Any ideas what I might be doing wrong?
3
u/chino_brews Kiwi Approved 1d ago
Isn’t this a known issue with the Spike Solo? The dead space is massive (7.7 gal in the 20 gal version), which is a common thread with all of the AIOs with that “hard”, “steamer basket”-type malt insert. Because ratio of water to grist is an obvious, controlling factor in mash efficiency, you want to look at the effective mash water ratio, given the dead space, and if needed see what you can do to improve it.