Struggling to achieve post-boil volume

I’ve brewed 4 batches of AG at this point, and I was wondering what others have done to achieve the desired post boil volume. I shoot for 5 gallons, and I’ve been all over the place by the end of a 60 minute boil. I try to maintain a steady rolling boil that’s not too aggressive. I brewed the rye stout and collected 6 2/3 gallons of pre-boil wort, boiled it for 60 minutes, whirlpooled it, and after factoring in what I had lost in the boil kettle with the hot break, I got exactly 5 gallons in the fermenter. Unfortunately, the rest of the batches didn’t go so well. I collected 7.25 gallons of a Blue Moon Clone I brewed, went outside to boil it, struggled with the wind to keep my boil rolling (got to build a windshield for my burner), and all that I had to put in the fermenter was not quite 4.5 gallons. I was short on the other 2 batches too, and they weren’t brewed on windy days. I’m sure every system is different, but do different beer styles evaporate at different rates? Are there times when adding a little extra HLT water to the boil kettle pre-boil is a done to achieve desired post-boil volume? What pre-boil volumes do you all typically start with? I’m sure I have to dial in my system on this issue, but I was just wondering if anybody has any helpful ideas. Thanks.

My kettles are kegs, and I spent some time marking out a known volume on them. So when I brew I will start in the HLT with 8-1/2 gallons. Why so much? When I brew IPA’s I tend to use lots of hops and know that I will lose real close to a gallon in the trub factor. When I do a Belgium golden strong I do tend to boil longer and will lose volume due to evaporation, not too much to trub as few hops. So having the extra water AND knowing my system AND what type I am brewing gets me to my post volume, oh yeah, don’t forget, I’ve repeated most of my favs at least a dozen times so I am familiar with what I’M doing…… repeating helps you, and document ALL the steps. I have a couple of note books full of notes, some I should throw out but then I may want to pull out a mystery brew and try again! Sneezles61 :cheers:

What I do is start with 6.5 gallon boil and shoot for 5.5 post boil. I check the volume every 15 min during the boil and adjust accordingly. After chilling what ends up in the fermenter depends a lot on the amount of hops you use. If you end with less than five and your og is good I would leave it. If og is low or high adjust with DME or water. You should concentrate more on hitting you’re gravity than hitting your volume.IMO

Thanks for the responses. As an example, I got 82.5% efficiency on my Blue Moon Clone which means when I over-evaporated it, I was left with a OG higher than what I wanted (confirmed with my refractometer). I was aiming for a drinkable summer beer, not a high alcohol one. I would rather have had 5 gallons of lower alcohol beer than 4 gallons or so. So it’s OK to add water back after boiling? I have to do a number of water adjustments to my water based on Bru’nWater’s spreadsheet. So it would be OK to up my HLT water volume and just add some to the fermenter to make up the volume? Or would it be better to add it before the end of boil? I would feel more confident I killed off everything if I boiled it for at least 5 minutes since the HLT water would have cooled by then. Thanks again.

Yes add your treated water from the mash run.

You’re not alone. Depending on the time of year I get different boil off rates thus I can not tell what volume I’ll end up with.

Thank you guys for the advice. Is there a rule of thumb as to how much beer an ounce of whole hops will absorb? I’m planning on doing an IPA or DIPA this fall depending on how well my Chinook and Cascade hops do in my garden this year. I’m probably looking at doing everything from FWH to HS to dry hopping this beer. I could be looking at adding 10oz in there. What volume loss can I expect? Thanks again.

The best estimate of water absorption per ounce of whole hops that I’ve seen is 0.15 qt/oz. If you are left with a smaller volume of higher gravity wort than you like you can either add additional sterile, chlorine-free water into the carboy or at bottling. He is the resource I use:

I think we all deal with this. I think the best we can aim for is +/- a 1qt or 2qt. In Promash I have it set up to default 15% rate. I am with Lowville: weather and more specifically relative humidity is a factor. I have a spoon with notches to gauge progress and adjust burner up or down or sometimes will even shorten or extend the boil. I think the key is assessing where you’re at mid boil.

Hi - so far I have only brewed Extract but am lurking here trying to learn as much as I can before I make the plunge!!

So, with my extract I do full (almost) 10 gallon boils but my kettle is just a little on the small side so I typically end up with 9 gallons. Then I just top up in my two fermenters to just a little over 5 gallons each (6.5 if a big DIPA). Seems to work just fine - I am happy with the taste of the beer!

Would this same method work OK with AG. I’m assuming I can add some light DME if I need to up the gravity a little or is this a no no?

Thank you

Perfectly acceptable .

Thank you