Blichmann 20G Kettle for BIAB

[Morrey]

I have been kicking tires to either add some mods on my 15G boil kettle, or possibly buy a new one. I do 5.5G batches exclusively since I keg into soda kegs.

I was looking at Craig's List and almost couldn't believe there is a local guy selling brand new a Blichmann G2 20G boil kettle along with a Speidel 60L fermenter and some associated gear at a price that made me say WOW!

This is all brand new stuff still in the box. He said he wanted to do some home brews and just never got that interested. All this is less than 50% of the price it would sell for online.

My 15G is really almost too big for 5.5G batches but I liked the extra room since I BIAB. I know this 20G adds even more headspace, but now I am torn what to do. Is 20G simply too big for my 5.5G batches? I hate to pass up this deal, but if the shoe doesn't fit, why buy it? Don't even know if 7G of strike water will reach the thermometer probe? Ideas?

 

[Troutchaser]

It would be nice to have for 10 gallon batches but If your only gonna do 5 gallons at a time stick with your 15 gallon kettle.

 

[btbnl]

11G batches will fit nicely into 2 kegs.

Just sayin'

 

[Morrey]

11G batches will fit nicely into 2 kegs.

Just sayin'

I considered that factor since the deal includes a 60L Speidel fermenter. When I do Pilsner beers, I have always wanted to do double batches. As long as the strike water (7G) for a 5.5G batch covers the thermometer probe in this 20G kettle, I am heading in the direction of this purchase.

 

[tmendick]

I'd imagine your boiloff would be horrendous with that much surface area.

 

[BeardedBrews]

I'd imagine your boiloff would be horrendous with that much surface area.

Your boil-off will go up, but that may not be a bad thing. A thinner mash can produce higher conversion efficiency, and adding a bit of volume does help stabilize the temperatures. Plus a slightly higher volume does make your brewhouse number look worse, but that might be worth it if you struggle with high levels of trub in your primary.

As long as the strike water (7G) for a 5.5G batch covers the thermometer probe in this 20G kettle, I am heading in the direction of this purchase.

If you're shopping for a new kettle anyway, but the 20 gallon. The thermometer on the G2 20 Gallon is at 7.4 Gallons, which should be fine for strike and mash temperatures in a 5.5 gallon BIAB. The advantage in being able to double batch or hit a high gravity single batch without sparging is just pretty big

 

[tmendick]

Wouldn't the increased empty space in the vessel negate much of the temperature stabilization improvement?

 

[BeardedBrews]

Wouldn't the increased empty space in the vessel negate much of the temperature stabilization improvement?

To a large extent, yes. Certainly the most stable solution would be a floating lid, which could be an easy DIY if you found you needed it.

The OP will have to insulate the kettle or add heat regardless of the approach. If he goes insulation then just insulate all the way up the walls, over the lid, and under the bottom, and it should hold pretty well.

Truth is, the "adding heat" scenario is the one that will probably cause the most trouble. The tendency is to either heat or insulate, but that can lead to temperature stratification in BIAB (just my experience).