Brew kettle diameter

**Kosch** · 02-02-2012, 07:41 PM

So I'm looking to get a new brew kettle, looking at the 40qt megapot from AHS. I was surprised to see that it was so wide, 16" diameter and 12" deep. Trying not to break the bank here, but the Polarware is 15" diameter and 16" deep.

I know that's not a huge difference, but I'm wondering, have any of you considered the diameter as how it relates to boil-off rate when deciding what to buy? My current BK is a 20qt, 12" diameter. I lose maybe 2.5 quarts over an hour.

I'm only doing partial mashes now, looking to go all grain soon, but just trying manage losses as much as possible.

Or maybe I'm worrying too much about it??

Thanks!

Kosch

PoppinCaps · 02-02-2012, 07:45 PM

In terms of AG, my opinion is that a higher boil-off is better, since you can likely extract more sugar from the sparge starting with a higher volume. Someone correct me if I'm wrong. And yes, typically a larger diameter will give you more boil-off. My BK is 15" and I get a pretty standard 1.1gal/hr with a nice boil.

badhabit · 02-02-2012, 07:52 PM

You also need to consider heating effeciency and burner size with larger/smaller diameter....now would be a good time for all you engineers out there to chime in with all that good techno info

**Kosch** · 02-03-2012, 04:40 AM

@PoppinCaps
Thanks for that. I think I was just overthinking it, but also didn't know about the possibility of starting with a higher volume to extract more sugars, makes sense. Curious, do you brew inside or outside? If outside, have you noticed much difference in boil-off rate with humidity/temp changes?

@badhabit
That is a good point as well. I'm planning on converting it to an electric kettle, but for now it would just be on my stovetop (electric), so I'm wondering if it will be too big heat evenly. Unfortunately the engineers didn't hear the call! lol

prrriiide · 02-03-2012, 04:51 AM

Quote:

Originally Posted by Kosch

If outside, have you noticed much difference in boil-off rate with humidity/temp changes?

Absolutely. I boil off much more in January than I do in July, due to (much) lower humidity. My boil off in July is about 1.2 - 1.4 gph. In January, it's more like 1.8 - 2.0 gph. (10 gallon boils) depending on how vigorous I run it.

A fellow homebrewer gave me the following advice: if you are getting hop pellet particulate stuck to the sides of your pot, your boil is too vigorous.

PoppinCaps · 02-03-2012, 12:25 PM

Interesting, I didn't think the boil could be too vigorous. What's the down side?

I do see some difference in boil-off, but not much, maybe 0.2-0.3gal more in the summer for 6gal boil.

badhabit · 02-09-2012, 03:38 PM

I would for sure be asking more questions if I was planning on putting a pot that large a diameter on an eletric burner. I think that you might have a tough time getting a good boil on a full boil. Sorry I can't give you more specific. I just know that I got a bigger boil pot and heated on a gas stove for a while. It took for ever to get it up to a nice boil. I eventually got a turkey fryer and saved a ton of time.

**BamaRooster** · 02-09-2012, 03:48 PM

The pot I use has an 18" diameter. It gets placed over 2 burners on my electric stove and I have no issues bringing 6.25 gallons to a boil. Granted it takes a bit longer than a turkey fryer but I would rather brew indoors.

strambo · 02-09-2012, 03:50 PM

My pot is that size, I have it on 2 burners on my electric stove. The large burner goes to the edge, and the smaller one is about 3/4s under the pot. I have only boiled 4.5 gals so far. Would need some sort of insulation to do more.