Upgrading my mash tun

[dmcman73]

Currently I am using a 10 gallon round cooler as my MT. I was never comfortable with using the plastic and have heard quite a few people state that the liners in their coolers have cracked from the heat of the water over time.

I currently brew 5 gallon batches but I plan on brewing some 10 gallon batches "when needed" so I was thinking of getting a 15 Gallon Stainless steel kettle for the new MT. My plan is to make a bottom drain MT and one that would tip to make dumping the grains easier. I will be wrapping the kettle with the "standard" reflective wrap everyone uses here and then topping it off with wood slats similar to this: https://www.homebrewtalk.com/f85/wooden-mash-tun-452994/ to make it look nice.

Since the majority of the time I will be brewing 5 gallon batches and on occasion brew 10 gallons, would a 15 gallon MT be "too big" for 5 gallon batches? I've read that some say because there will be to much dead space and cause more heat loss than a smaller MT for a 5 gallon batch. Has anyone built a second lid that can go further down into the kettle to minimize the dead space or is that not needed?

Right now my BK is a 10 gallon kettle that I will be upgrading to a 15 gallon in a few months so I can do 10 gallon batches and I've purchased an additional 7.5 gallon spiediel fermentor so that I can split the 10 gallon batch between the two. Would I need to also upgrade my HLT from the current 10 gallon to a 15 gallon as well? I mainly fly sparge when I mash so would the current 10 gallon suffice for 10 gallon batches?

Thnaks!

 

[Bensiff]

Its about surface area, not volume. I would go for a 20 gallon size that has low enough surface area to handle the 5 gallon batches; but, enough capacity to do a hefty 10 gallon batch. I use a Stout 20 gallon MT and have no problem doing 5 gallon batches in it.

 

[dmcman73]

Hmmm, I was thinking of getting this 62 quart kettle: http://www.amazon.com/gp/product/B000VXD94A/?tag=skimlinks_replacement-20. Would you say that this does not have an ideal surface area for a 5 gallon batch?

 

[Bensiff]

Yeah that'd work. My stouts are 15.75 IIRC.

How are you maintaining temps? Just hoping the insulation will work as well as a cooler? I'd tend to think it pretty hard to match that so you might want to build thinking about that, whether it be electric or propane or perhaps a propane HERMs system.

 

[uphillbrewer]

I've started using a 15 gallon pot as a mash tun recently, after using a plastic cooler for years. I also used reflectix wrapped around and secured with Velcro.

Works just fine, however I've had a hard time dialing in strike temps and sometimes maintaining temps if they are low. Raising temps to mash out can be a bit tricky, but with a bit of Patience works fine. I also like that I can mash 10 gallons of a big beer in it, as well do normal 5 gallon batches.

I've considered adding a pump to recirculate when adding heat to maintain consistent temps.

 

[Black Island Brewer]

I use a keggle with a side drain, and use a Velvet Shield welder's blanket as insulation so that I can direct fire with the insulation on the mash tun. I have a strip of reflextix tape around the top and bottom to keep particulates from getting in behind it. Even in cold weather I typically see around a 1-2 degree drop in 60 minutes.

 

[dmcman73]

That sounds promising especially since I brew indoors, I have an all electric setup. I may try using the expanding foam between the wood and the kettle like how all the coolers are. I'll set it up to have a thin aluminum or something else on the back of the wood to keep the foam from pressing through the slats of the wood.

 

[blizz81]

Yeah, might be a good time to go RIMS or HERMS as you're switching up vessels. Anything against the standard keggle for your mash tun vs. a kettle?


I would just add that any insulation wrap (reflectix and/or wood slats, etc) you add, you should ideally be able to remove to be able to clean the outside of the vessel. Reflectix recommends your installation not be directly up against the vessel anyways, a plus of using velcro like others in here have mentioned.


My keggle did not hold temp very well on a 5gal batch test run before I installed my RIMS tube, and that was indoors with three layers of reflectix wrap, and a tight-fitting lid (though no insulation on inside of lid / top of grain bed).

 

[dmcman73]

I think what I am going to do is either get a keg, or a kettle (whichever I can find first at a good price) and then build a "barrel" (just a bunch of wood slats going around and tied together with some sort of metal band) around it, something that is about 1.5-2" larger in diameter than the OD of the kettle/keg. I am going to then line the inside of the barrel with aluminum. For The kettle/keg I'll wrap it in aluminum foil and set it inside the barrel. The top portion of the barrel will have a round wood collar that the slats will attach too and will be a tight fit for the kettle/keg to fit into, I'll then seal it with some clear high temp silicone. The aluminum sheet attached to the wood will be glued to the wood with the same type of silicone and this should create a nice water repellent seal to keep water off the insulation. The foam will then be injected from the bottom and then sealed off with a wood cover. This will give me as close to the same insulation as a standard water cooler (it's just insulation foam between the plastic liner and outer shell). the aluminum on the inside of the barrel will keep the foam from squeezing out from between the slats. As for the last part, I'll stain the wood, seal it and then wrap it with copper bands (to hind the screws) just to add some "bling" to it. Since this will be in my house and my wife will see it every time she goes downstairs, it's best it's not an eye sore and looks nice.

The kettle/keg will be low enough in the barrel where I can make a stainless steel lid to sit on top of it that has a foam/wood casing for the insulation as well.

This is going to be done over a course of time, I'm not in a huge rush to do this as my cooler is still good but since I pre-heat it with boiling water, I am expecting the liner to crack at some point just as a lot of people on here have experienced with theirs.

I am going to build this with a bottom drain as I believe that this will drain far better than a side drain with a false bottom?

 

[uphillbrewer]

I don't think you need to preheat your cooler with boiling water. If you use hot tap water (whatever the warmest that Comes out of the tap) and let it sit for a bit, I would imagine it preheats it well enough. You can also adjust your equipment temps in Beersmith to reflect the current temp of your cooler, either preheated or not. Just a thought.

 

[Bensiff]

Wow, I think I only bothered preheating my cooler a few times and that was because it was in the 20s outside. I've never had a need for it, just adjusted the math to compensate. I don't believe the plastic is designed to handle 212, it's fine for mash temps but not much beyond IIRC.