I participated in a Kickstarter (https://www.kickstarter.com/projects/958078058/chapman-homebrew-equipment-mash-tuns-fermenters-ke), because I wanted a stainless insulated MT.
It arrived late last week. I quite pleased with it with the exception of the false bottom - which isn’t bad, I just think the Blichmann false bottom is the best. So I am going to have my son-in-law who is a pipe fitter make the Blichmann false bottom to work in the new MT. I need to try it soon! Here are the pics:
Shiny!
I am not a fan of the Blichmann design. In my humble opinion, it’s a bit of a hack. If you are going to use a false bottom, your money is better spent on a slotted design (that’s what’s used on commercial tuns). A 16 to 20% open-space slotted design false bottom is a work of art from a mash bed fluid dynamics point of view. What is the diameter of your tun?
By the way, I do not know why tun and kettle manufacturers continue to choose compression over 37-degree flare fittings for pick tubes. A compression fitting requires a oval shaped hole in the false bottom, an oversized hole, or play between the sides of the kettle or tun and the false bottom. A flare fitting does not because the tube goes on the fitting, not in the fitting. A flare fitting can be disassembled and reassembled a thousand times without having to replace a ferrule, and it only needs to be finger tight for brewing applications because the fitting is designed for high-pressure applications.
One can see here that a flare fitting requires zero play
Here’s what the tube looks like on a 37-degree flare fitting
Here’s what the fitting looks like inside of the kettle
Edit: This kettle/false bottom combination were designed for use with whole hops. It is not a mash tun.
The Blichmann is the best one I have used. And I still have it so I might as well use it. The only other one I have used is similar to the one that came with this unit and what you show in your pics. Just holes in a stainless plate. I would definitely like to try the slotted design you speak of. Now I wonder if it would be easier for my son in law to make a new slotted one than cutting a bit from the circumference of the Blichmann… I’ll have to ask. They do have a water jet cutting device.
The diameter of the new MT is ~15.5".
The stainless slotted material is the same used for well screens. Johnson Screens in Minnesota made the stuff and was a customer of mine.(back in the 80s) We were able to buy flat stock and fitted up a bunch of brew kettles. The stuff is superior to anything else for false bottoms if you can find some. Don’t know if a comml brew house fabricator would sell a piece, but thats what I’ve seen in the PKW systems I’ve looked at among others.
Here’s my mash tun:
I purchased this false bottom from Adventures in Homebrewing. The guy who designed this false bottom for Jay designs and builds commercial brew houses. I had a long conversation with him at NHC 2014.
Is that their 9" version? That is cheap enough I may just do that rather than bugging my son in law with a new project. How much grain to you get passing through it? You mentioned fluid dynamics, what specifically is better about this design?
Yes, that is AiH’s 9" slotted false bottom. I brew mostly 3.75 gallon batches. However, I do brew the occasional 6-gallon batch.
I used to use Phil’s Phalse bottoms in 10 and 7-gallon Gott coolers, which were basically plastic versions of the dome-shaped perforated steel false bottom that is sold for 10-gallon coolers today. The best extraction rate that I could eek out with a perforated false bottom and imported malt was a mixed-grist rate of 31 points per pound per gallon (PPG), and that was a rare event. My consistent mixed-grist extraction rate was 28 PPG. With the slotted design, my consistent extraction rate with imported malt is 32 PPG, which is kind of a sweet spot for me. I actually have to be careful now to prevent going too high. I have hit 35 PPG with a mostly continental pils malt grist. I personally believe that a beer starts to suffer at that extraction rate, at least in my brew house.
Besides having an open space of 16%, I believe that lot of the improvement in extraction rate is due to the fact that the slots are difficult to plug. I used to have spray water through my perforated false bottom after dumping the grist because so many of the holes would be plugged. Plugged holes lead to uneven draining. Uneven draining is not a problem if a brewer batch sparges, but it is an extraction rate killer with continuous sparging.
That looks pretty nice; let us know how you like it.
I’m seriously considering the SS Brew Tech version.
Yeah I have their fermenter and love it. Theirs does look excellent. At the time I ordered mine they only had a 10 gallon version, that is why I went with the Chapman kickstarter. Glad they have a 20 gallon MT now - even if it is not yet available.