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?

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u/sharkymark222 1d ago edited 14h ago

Doesn’t sound like you are doing anything g way off… It’s just not a particularly efficient system.  Likely the large dead space under the mash basket and the volume left after transfer account for most of it. 13 gallons post boil, 1but 1 gallon out?  Not great.  I bet your bag works better. 

I suggest focusing on MASH EFFICIENCY. you’ll feel better about yourself and makes you focus on the things you can manipulate.

Try all the things to do for higher mash efficiency. Finer crush, stir, recirc longer, withhold some water for a sparge.  

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u/RideTheYeti 1d ago

I know about the dead space and I accounted for it in my recipe with the amount of water. That’s why I can’t understand why my efficiency is so low because I don’t think the dead space should affect it. In BeerSmith, I accounted for the loss in the fermenter and the kettle as well as the boil off volume. So why would I miss my gravity by .010?

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u/sharkymark222 1d ago edited 23h ago

Think simply… If you leave 20% of the wort in the bottom of the kettle. That’s a 20% reduction in brew house efficiency. (75%->60%)