First time i brewed a 5 gallon batch, got 3.5 gallons

I understand that during the brewing process some wort boils off, spillage etc… happens, But is there anything i can do for next time while i brew to make sure its at 5 gallons? :?:

Are you saying you only had 3.5g going into the fermenter after the boil, or did you have 5g in the fermenter and only ended up bottling 3.5g? If you didn’t have 5g after the boil then simply increase the amount of water you’re using pre-boil to compensate for what’s being boiled off, this takes some trial and error, I’ve found that 1g on a propane burner or 0.5g on the stovetop per 60 min works for me. And if you come up short you can top off to 5g in the fermenter. Beyond that you can scale your recipe to 5.5g or so in order to compensate for trub loss/hydro testing post boil.

it was 3.5 gallons going into the fermentor, but i guess this means i gotta buy a bigger pot because the one i have will just fit 5 gallons barely. Or do you think i could have a separate pot on the side to add in the boil periodically?

A lot of folks start out doing partial boils, just boil as much as you can in your current pot and top off with water in the fermenter so you have 5g(or 5.5g or whatever your recipe size is). Your other option would be split the boil between 2 pots if you have another decent sized pot and you want to do a full boil. At some point if you stick with brewing you’ll probably decide to buy a bigger pot that will accomodate a full boil with enough room to minimize boilovers. They aren’t really that pricey unless you’re interested in the one of the “made for brewing” pots with all the bells and whistles sold on the homebrew sites, those can be pretty outrageous, but just about any SS or Alum. pot will do.

What was the OG of the 3.5 gallons of wort and what was the expected OG for the 5 gallons you intended to get? When it’s bottling time you could use more water when making your priming solution to bring the batch size up to match your intended OG.