15 gallon boil kettle too much surface area for small batches?

Right now I'm pretty much just doing 5 gallon batches (extract with specialty grains), but I got a really good deal on a 15 gallon pot so I have that now which I plan to grow into.

I've searched the forums for the smallest batch you can do in a 15 gallon pot but not finding this specific answer: Is there too much surface area (in other words too much evaporation during the boil) if I'm only boiling about 3 gallons of liquid?

OK. For the life of me I could not find this answer and after I posted, I was linked to threads that answered this exact question. So, my apologies to the veteran posters for that.

So my updated question is, if I can estimate how much liquid I will lose during the boil, can I just add that much extra at the beginning? Or will that completely throw off the boil gravity?

No reason to only boil 3 gallons if you have this kettle. Do a full boil, no top up water. You will get better hop utilization too.

I do 5 gallon ag batches in a 15 kettle


I usually aim for 6.6 gallons pre boil volume for a 5 g batch

It isn't the surface area of the wort that determines how much you boil off, it's the power input. You might have more boiloff with a wider pot, for a given flame, but that's because of the wider base for the flame to hit, not the wort surface. Adjust your flame to give you the volume loss you are going for.

If you are just doing 3g batches for experimentation then go for it, you will just have to watch your evaporation closely as there isn't as much thermal mass so smaller changes in your heating source will impact your evaporation faster than if you are changing your heating rate on say a 10g batch. You will have more evaporation in a wider pot than a narrower pot, just based on surface area. There are a lot of factors to take into account to make such a wide assumption, give us some more details in your setup and what you are planning on doing.

-G

Thanks for all of the input!

So, going back to the full wort boil and better hop utilization, I'm assuming I would have to adjust the hop amounts down a bit? Sorry for the novice question. I just finished reading John Palmer's "How To Brew" so am just getting into the technical ins and outs of brewing. I seem to remember a section on boil gravity and IBUs that I'm going to have to look up when I get home.

Any input from the vets on that is much appreciated though!

ITbrewer229 said:

Thanks for all of the input!

So, going back to the full wort boil and better hop utilization, I'm assuming I would have to adjust the hop amounts down a bit? Sorry for the novice question. I just finished reading John Palmer's "How To Brew" so am just getting into the technical ins and outs of brewing. I seem to remember a section on boil gravity and IBUs that I'm going to have to look up when I get home.

Any input from the vets on that is much appreciated though!

Click to expand...

No, not really. It used to be thought that wort gravity impacted utilization, but it turns out not to be correct (per John Palmer and others).

If you can do a full wort boil (and cool it!), then just do it. The beer will be better for it.

Awesome. Thanks! I have a 50' x 1/2" wort chiller so I'm good there. I'm going to give this a try on the next batch. I have my first barley wine ready to go.