Tomorrow will be my first all grain session 5 gallon batch. I am trying to keep it simple and take plenty of notes so that I can get dialed in after a few batches. So if I mash with 4.25 gallons and collect 3.1 gallons of wort then my batch sparge water should be 2.65 gallons to make my preboil batch size 5.75 gallons. So if my preboil gravity is 1.040 then generally speaking my post boil should be 5.75 * 40 = 230 = 230 / 5 = 46 or 1.046 assuming I boil off .75 gallons. Give or take. Does this sound right?
just brew it and note what happens. you’re overthinking this project
Nothing wrong with a little planning and extrapolation. Don’t be overly concerned if you miss it by a point or 2 in either direction. The calcs look right to me but I use beersmith2 so I let the software tell me those things.
Calcs are correct , but five gallons of hot wort will shrink about a quart when it cools.
Accounting for trub and yeast and slop in the primary and you’ll have close to a 4 gallon batch of beer.
This can go on and on and on and on.
Gotta learn by doin.
I also just use beersmith. Makes it easier so you don’t have to write all these calculations out. Put your equipment data in before you start and you can go from there for any recipe (although some data may change as you enhance your process).
Beersmith allows a 30 day free trial so you could do that to see if you like it. If not just delete it.
For my first batch I used some estimations and hand written calcs too, but found I like the software better. You can also keep all your notes in there so you know what you did and why and how to make it better next time.
Brewer’s Friend is a really easy to use web-based system that can help you calculate your mash and sparge volumes based on your grain bill, desired mash thickness, expected efficiency and equipment settings…
Without knowing anything about your equipment or grain bill, it’s hard to say what the correct volumes should be. Taking detailed notes is a great suggestion. That said, you may want to either increase your sparge volume, be prepared to add some top-off water or accept a lesser volume of stronger beer. A 0.75 gal/hour boil-off rate is something I’ve never experienced, but that doesn’t mean it isn’t possible. I typically experience 1 to 1.5 gallons per hour, but that depend on a lot of factors (ambient temperature, atmospheric pressure, how vigorous the boil is), so YMMV…
[quote=“brentconn”]So if my preboil gravity is 1.040 then generally speaking my post boil should be 5.75 * 40 = 230 = 230 / 5 = 46 or 1.046 assuming I boil off .75 gallons. Give or take. Does this sound right?
This is a great calculation and will helpful to you for a long time. It will also allow you to adjust going forward based on your mash efficiency.
You will have some loss with your sparge as well though, so infusing 2 gallons won’t yield you 2 gallons of wort.
You’re off to a good start and you haven’t even started!
By my calculations you would end up with less than 4.5 gallons after all the yeast and everything comes out. If you want 5 gallons at the end then sparge with more water – instead of just 2.65 gallons, use 3.33 gallons for the sparge. This will not just increase final volume but will also improve your efficiency. The other thing with this, of course, is that your fermenter either needs to be able to handle 6 gallons, or you need to split into two 3-gallon carboys or whatever to make it all fit.
That is my one comment, otherwise looks like you are definitely well on your way to brewing great beer. Enjoy!
I am definitely underestimating my boil off numbers. Thanks for the input. :cheers: