I am confused about the instructions for boiling the wort in an extract kit. Seems like all the kit instructions say to start with 2.5 gallons of water. I have a 6 gallon pot and have no trouble getting 5 gallons to a rolling boil. Should I still use the smaller quantity of water to start? It seems to me that you end up with the same result - 5 gallons of wort. If you add unsterilized water after the boil isn’t there a danger of infection?
Boil as much as you can, but know that your hop utilization will change. Meaning, if you have a larger boil volume, your IBUs will go up because of better hop utilization. So what I would do is plug the recipe into some sort of brewing software (I use hopville.com) and adjust your boil volume up to 5 gallons. Your final gravity will stay the same, but the IBU’s will go up. You may want to reduce the amount of hops to counteract this problem. Or do like me and just be happy for better hop utilization and a hoppier beer!
And yes, you can top off with clean sanitized water. I would use filtered water or even purified bottled water when I did partial boils. Never had a problem.
If you can do a full boil, do so.
But boiling five gallons isn’t a full boil. You will end up with 4 gals or so after the boil and still have to add water. I still would do this over a smaller boil though. will be much better with hop utilization.
I appreciate the help! I’m not sure I"m reading this correctly - the first answer said better hop utilization with a larger boil and the second one said a smaller boil? Still confused!
With the 6 gallon pot you can boil larger amounts than the 2.5 gallons mentioned in the recipe. The 2nd response simply mentioned with a 6 gallon pot, you will not have enough room to boil the full 5 gallons at once.
Figuring for around 1 gallon per hour of water evaporation, you would need to start at 6 gallons (the limit of your pot). Still if you were to start with say 5 gallons, and boil down to 4 you would still top up to 5 in the carboy / bucket. Whether your performing a full boil (5 gal) or increased size boil (> than 2.5 gal) you will have better hop utilization so that may need to be accounted for with brewing software.
and if you’re steeping grains, you still need to do this in ~2-3 gallons of water. If you use more it will start to leach tannins. trust me, i have 10 gallons of that mistake right now
Also 5 gallons is harder to cool down quickly. That’s why many people do partial boils if they are limited to brewing indoors and/or don’t have chilling equipment.