So I had what was a relatively uneventful brew day (or so I thought) until I checked my gravity prior to pitching yeast. I was expecting something around 1.066 or a little higher. Instead, I got 1.059. Here is the break down of how it all went.
Mashed at 154 with 4.75 gallons of water (water temp 170 degrees)
Fly sparged 6.50 gallons ( water temp 170-ish degrees)
Added a total of 7 ounces between boil/flameout/whirlpool
Boil volume at start was around 8.1 gallons.
Ended up with 5 gallons in the fermenter.
Its funny because this is my 4th all grain batch and my very first one over the summer was only off by 2 gravity points going into fermentation. Any and all help/advice/suggestions are greatly appreciated. For all 4 batches I have fly sparged. I may take a stab at a gose in a couple weeks… at least those are supposed to be lower ABV! Thank you in advanced.
Sounds like you boiled off a ridiculous amount unless you left like 2 gallons behind in the kettle. Something isn’t right there. If there was a bunch left then I’d say you over sparged and that watered down your wort and that’s why your gravity was low.
I mill at my lhbs. However, will be getting my own mill just in time for christmas. As for the volume numbers, I do agree it needs to be looked at. My preboil gravity was off by I believe 3 or 4 points. I didn’t think that number would become greater as wort would be boiled off? I am trying to dial in exact volume numbers as I upgraded to a 10 gal kettle recently. I feel like every calculator gives you a different number when it comes to strike water and sparge water (volumes).
I would measure what you are leaving behind in the kettle. I leave extra behind in my kettle for the sake of clearer wort in the FV. I throw pellet hops in the boil loose and collect around 8.5 gallons pre boil. I will do a little more or less depending on hopping amount. I end up with 6 gallons in FV after 90 minute boil. I leave about a gallon sludge in the kettle. Hope that helps.
Pre boil gravity was around 1.050
Gravity going into the fermentor was 1.059
Preboil volume was around 8.1 gallons and I ended with 5 gallons going in the bucket. I left behind a good slurry of hops at the end of the kettle. The boil was for 70 minutes. I usually boil for 60, but once I realized my preboil gravity was off, I thought I would try to compensate by boiling for 10 more minutes.
Assuming those numbers are correct, your post-boil volume was ~6.9 gal, and the problem is simply starting with too much wort in the kettle. If the recipe you’re brewing is based on a 5 gal volume, then you need to start with ~6.2 gal to boil down to that (based on 1.2 gal boiloff for this batch).