Broader vs Taller kettles

I just got 2 new stainless steel stockpots, an Update International SPS-60 which is 18.625" dia, 14.75" high, and a Bayou Classis 62 qt pot, at 15.25 dia, 18.5 in high. So, the Bayou is taller and narrower.

I planned to use the SPS-60 for a boil kettle, and the Bayou for a MLT (which I will insulate). Before modifying the pots, I used the SPS-60 today for a partial mash batch. i started with 6.5 gal pre-boil volume, expecting to end up with 5 gal, however, at the end of the boil I ended up with 4.5 gai.

Should I stick with my plan, perhaps adding .5 gal to the pre-boil volumes for my 5 gal batches, or perhaps switch and use the Bayou for the boil kettle. Perhaps because it is narrower, it would have a little less evaporation loss. On the other hand, it is a bit lighter, and has an inner lip at the top for holding a steam basket that might be annoying to clean.

pincorrect said:

Should I stick with my plan, perhaps adding .5 gal to the pre-boil volumes for my 5 gal batches, or perhaps switch and use the Bayou for the boil kettle. Perhaps because it is narrower, it would have a little less evaporation loss. On the other hand, it is a bit lighter, and has an inner lip at the top for holding a steam basket that might be annoying to clean.

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My guess is that the taller, narrower pot will have a different boil off rate and that it will be less. I believe this because the surface are is also less. However, I don't know what the difference would be without doing some testing. Do that and it may help you to decide.

What i really wanted to comment on is the lip for holding the steamer basket. My boil kettle has a rolled edge toward the bottom for holding a steamer shelf. I do not have any problem cleaning around that. If you have what I have on my kettle, I don't think you will have any problems cleaning.

If you do a test to see what the boil off rate is, I would be interested in knowing what that difference is.

Thanks,

Mark

I think you're right. I think the Bayou Classic pot is closer in shape to a keggle, and probably has similar boiloff. if I get a chance to boil another partial mash batch, I'll use it and post the result. On the other hand, I'm waiting for fittings I ordered late last week, and when they come I'm tempted to go ahead with my original plan because dealing with these big pots without drain valves is a real pain!

I have the Update International 100 quart pots, which are wider still. I find that my boiloff rate is higher than what I typically see expected in recipes. Remember that most keggles have not only a narrower diameter, but also an inner lip left from cutting out the top, so that the effective diameter is much smaller. I batch sparge, and have just adjusted my sparge volumes to get to the post-boil volumes I want. On my system, I typically use a total of 16 gallons of mash and sparge water to put 11 gallons in the fermenters, tweaking up or down a bit for pounds of grain or for a longer boil. It sounds like you are keeping good notes. It should not take long to dial in your system.

I'm hoping that as long as I don't boil so vigorously that the wort or hot break material scorches, there will be no issue collecting a little extra sparge water to allow for the increased evaporation, e.g. 7 gal initial volume instead of 6.5 for a 5 gallon batch.

With the SPS-60, that would be a little tight for doing a 10 gal batch, which might require 14 gal initially. However, I might eventually upgrade to a traditional 3 kettle setup, with the 60 as the HLT, and maybe the SPS-80 for the boil kettle.

The 100 must be huge! Is it challenging to clean after the boil?

I am not sure but I think I've heard that a wider kettle will also have better hop utilization (in addition to more boil off). Someone else can probably confirm or deny that though.

LuiInIdaho said:

My guess is that the taller, narrower pot will have a different boil off rate and that it will be less. I believe this because the surface are is also less. However, I don't know what the difference would be without doing some testing. Do that and it may help you to decide.

What i really wanted to comment on is the lip for holding the steamer basket. My boil kettle has a rolled edge toward the bottom for holding a steamer shelf. I do not have any problem cleaning around that. If you have what I have on my kettle, I don't think you will have any problems cleaning.

If you do a test to see what the boil off rate is, I would be interested in knowing what that difference is.

Thanks,

Mark

Click to expand...

Definitely true, all other factors equal, the more surface area that is boiling, the more evaporation. Just like in reducing a sauce, if you're in a hurry transfer it to a large sauté pan and it will go much faster.

With brewing I think the next question would be which of the two would chill quicker. I'd guess the wider but not sure.

I have both SPS-80 and SPS-100 (Update International Tri-Clad 80 and 100 qt) pots. They are the same diameter - the 100qt is just slightly taller. My evap rate is really low - maybe a half gallon in 90 minutes of boiling. But I also control the boil via an adjustable opening in my lid. As long as you know what the rate is, you just account for it in the recipe.

To your original question though: wide is better than tall IMHO. Wide kettles have better heat distribution.