Should I go forward with building a keg MLT?

I've been using a cooler MLT for the last few years and it works just fine. The only thing that kind of bothers me is the idea of heating up that plastic so much. I don't know if my MLT is made with BPA or not, it's a Coleman XTreme. I already have a keggle that I can convert to a MLT and I have the burners to handle the direct firing and the pump to recirculate. I've been researching here on the forum all the ways to insulate the MLT to hold mash temps and that sounds like a bit of a pain, but doable. I've been given gift certificates to get all the hardware I need to add a false bottom (from what I can tell the Jaybird false bottom is the way to go) and convert to a MLT. I'm just trying to decide if it's worth it. The hassle of making an insulating jacket for the MLT, having to clean all the grain out of that thing can't be as easy as dumping my cooler MLT, having to recirculate with the pump. I'm game if it is worth it and is safer for me and my drinkers I'm just trying to ascertain if it's really worth the trouble, time, and cost.

Any thoughts, suggestions are appreciated.

Cheers!

I thought bpa was only used to make hard clear plastics. The Coleman plastic is opaque and soft.

Although you just clued me in on a possible source of a particular plasticy off flavor... Maybe certain mash ph levels bring out some nasties from the cooler mash tun.

For me it was worth it. My mash temps were inconsistent at best (especially during the winter months). My MLT is a keg with a insulating blanket made out of a water heater blanket. I didn't want to direct fire, so I went with a RIMS tube. Now I just heat the water in my HLT, transfer to the MLT, set the RIMS controller and let it recirculate. For me it's worked great. Fairly simple project. Cleaning the MLT isn't an issue either. I've re-purposed and old book shelf that allows me to lay the MLT on it's side and simply shovel the grains into a trashcan.

https://www.homebrewtalk.com/f51/rims-dummies-114997/

BPA is not an issue with the Coleman cooler and you can recirculate just as easily.
I would be more worried about what's gonna happen if the breweries ever get serious about recovering their stolen kegs.
They ain't gonna find any AB kegs all cut up in my set-up.

PosterGuy said:

BPA is not an issue with the Coleman cooler and you can recirculate just as easily.
I would be more worried about what's gonna happen if the breweries ever get serious about recovering their stolen kegs.
They ain't gonna find any AB kegs all cut up in my set-up.

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Maybe they'll join forces with the milk-crate industry and finally see these DIY-ers pay for their crimes!

"what're you in for?"
"stolen kegs man"
"full beer kegs? cool"
"nah, empty"
"...."

PosterGuy said:

BPA is not an issue with the Coleman cooler and you can recirculate just as easily.
I would be more worried about what's gonna happen if the breweries ever get serious about recovering their stolen kegs.
They ain't gonna find any AB kegs all cut up in my set-up.

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How do you know that the Coleman coolers don't have BPA? I think that the breweries have much better things to do with their time and money than go after homebrewers and their old kegs. How would they ever find them anyway? Are they going to knock on doors in every neighborhood in America until they find a couple? I have absolutely no worry whatsoever about being "hunted" down for the keg I bought at a garage sale 3 years ago. I don't think you should worry about it either.

I'd guess that it's the exact same plastic used as those giant round coolers that are meant for hot liquids, so I wouldn't worry about it. The soft white plastic isn't BPA-type plastic anyway. Can't imagine Coleman having two "blends" of plastic for lining each different type of cooler - plus if one is designed to put food and drinks in it anyway, it'd probably be "food grade".

Are kegs lined with BPA like canned food?

I had a round igloo cooler (10 gallon size) for years. I still have it, but needed something bigger so I went with a keg. I preheat it, just as I did the cooler, by adding my mash water at 180 and then letting it drop to strike temps. After that, it holds temperature amazingly well. I was actually really surprised, because I've seen all sorts of ways to insulate a keg MLT here on the forum. I mentioned this to my friend who helped me build the MLT (cool tippy dump, with a bottom drain) and he said that stainless is actually pretty good at holding heat, even as thin as it is.

I do have a HERMS, but sometimes I don't even run it until going to mash out temps- and I still hold heat for an entire hour.

paulster2626 said:

Are kegs lined with BPA like canned food?

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No- just plain ol' stainless.

Yooper said:

I had a round igloo cooler (10 gallon size) for years. I still have it, but needed something bigger so I went with a keg. I preheat it, just as I did the cooler, by adding my mash water at 180 and then letting it drop to strike temps. After that, it holds temperature amazingly well. I was actually really surprised, because I've seen all sorts of ways to insulate a keg MLT here on the forum. I mentioned this to my friend who helped me build the MLT (cool tippy dump, with a bottom drain) and he said that stainless is actually pretty good at holding heat, even as thin as it is.

I do have a HERMS, but sometimes I don't even run it until going to mash out temps- and I still hold heat for an entire hour.

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Good to know Yoop. I don't have any interest in building a complex HERMS or RIMS system, at least at this point in time, so it's good to hear that yours tends to hold temps well. I don't have a brew stand so building a tippy system isn't an option for me right now. That's why I'm trying to get an idea of how much of a hassle it is to clean all the grain out of the keg after mashing. I guess you just have to scoop it out, no way around it.

BTW Yooper, I've brewed a couple of your recipes and loved them. Thanks for your contributions!

Yooper said:

I had a round igloo cooler (10 gallon size) for years. I still have it, but needed something bigger so I went with a keg. I preheat it, just as I did the cooler, by adding my mash water at 180 and then letting it drop to strike temps. After that, it holds temperature amazingly well. I was actually really surprised, because I've seen all sorts of ways to insulate a keg MLT here on the forum. I mentioned this to my friend who helped me build the MLT (cool tippy dump, with a bottom drain) and he said that stainless is actually pretty good at holding heat, even as thin as it is.

I do have a HERMS, but sometimes I don't even run it until going to mash out temps- and I still hold heat for an entire hour.

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Yooper, you mentioned that your keg MLT holds temps very well. There are many reports here on HT that say differently, why do you think yours holds temps so much better?

thanks

Beavdowg said:

Yooper, you mentioned that your keg MLT holds temps very well. There are many reports here on HT that say differently, why do you think yours holds temps so much better?

thanks

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I have no idea! I was fully prepared to insulate with that reflectix stuff, or to have to run the HERMS, etc.

One of my best friends in an electrical engineer and electrical contractor, and he is the one I mentioned how well it held heat and wasn't the least bit surprised.

It could be because I added 180 degree water to it, and let it come down to 164 for strike temps, I guess. The funny thing is, I always did that with my cooler and it would lose temp pretty fast, and then hold it. The keg MLT doesn't drop fast at all- it takes a long time to get to 164. So I'm actually adding cooler water (in the 170s) now so I don't have to wait as long to mash in.

I'll send a PM to my friend and ask him to comment on this thread, and see if I'm way off base or only a little crazy.

It's about the thermal conductivity of the material. Stainless is not a very good conductor for a metal. Here are a few exaples I looked up: copper-401, aluminum-250, stainless-16 and HDPE-0.5
Insulation will of course lessen the heat loss but depending on the system, it may not really be necessary. Heat some water in a keggle, let it equalize, cover and monitor it for an hour. You may be surprized.

Yooper said:

I have no idea! I was fully prepared to insulate with that reflectix stuff, or to have to run the HERMS, etc.

One of my best friends in an electrical engineer and electrical contractor, and he is the one I mentioned how well it held heat and wasn't the least bit surprised.

It could be because I added 180 degree water to it, and let it come down to 164 for strike temps, I guess. The funny thing is, I always did that with my cooler and it would lose temp pretty fast, and then hold it. The keg MLT doesn't drop fast at all- it takes a long time to get to 164. So I'm actually adding cooler water (in the 170s) now so I don't have to wait as long to mash in.

I'll send a PM to my friend and ask him to comment on this thread, and see if I'm way off base or only a little crazy.

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That's assuring since Friday night I will be brewing two batches at the same time and using a friends' keggle mash tun. I was concerned about temperature drop but hopefully it isn't an issue. It should be relatively warm in the garage, so I will just keep my eye on the temp for the mash.

BPA isn't bad for you. We know it is bad for rodents, it is not harmful to people especially adults. Rodents and people metabolise it differently.

The best bit is the stuff they have replaced BPA with is actually worse for you

Yooper said:

I have no idea! I was fully prepared to insulate with that reflectix stuff, or to have to run the HERMS, etc.


It could be because I added 180 degree water to it, and let it come down to 164 for strike temps, I guess. The funny thing is, I always did that with my cooler and it would lose temp pretty fast, and then hold it. The keg MLT doesn't drop fast at all- it takes a long time to get to 164. So I'm actually adding cooler water (in the 170s) now so I don't have to wait as long to mash in.

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I think you nailed it on the head there. I would imagine that the keg acts similarly to a coffee thermos. I have a (kickass) thermos that will keep coffee warm for a couple hours when I pour the coffee in. If I 'pre-heat' the thermos with hot water for 5 or so minutes before dumping the coffee in, it will stay hot for half a day if not more :rockin:

The metal (keg or thermos) will equalize with the liquid within. When filled cold, it will suck heat out of the liquid within to equalize, thus dropping the temperature of the mash/coffee. If you pre heat the keg/thermos it wont suck heat out to equalize (or in Yooper's case, preheat the keg above the desired temp, so that when the keg sucks out the heat it will equalize at the desired temp)

It also depends when and where you use the keg MLT. During the summer, my RIMS hardly has to work to maintain the temperature. I brew in my garage and during the winter, it really has to work.

Check out this thread, I did this last year and it works awesome (even added a gallon of volume). I preheat and don't lose even a half a degree in an hour mash.
https://www.homebrewtalk.com/f11/my-new-mash-tun-268370/

alexnharvey said:

BPA isn't bad for you. We know it is bad for rodents, it is not harmful to people especially adults. Rodents and people metabolise it differently.

The best bit is the stuff they have replaced BPA with is actually worse for you

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I'm not sure I'm seeing your statements here. Rodents and people are both mammals and metabolize products very similarly due to their very similar digestive and circulatory systems. From what I've read BPA can increase risk of breast cancer, which happens to both men and women.

Beavdowg said:

I'm not sure I'm seeing your statements here. Rodents and people are both mammals and metabolize products very similarly due to their very similar digestive and circulatory systems. From what I've read BPA can increase risk of breast cancer, which happens to both men and women.

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Yes, in general but they don't metabolise BPA similarly.

http://www.bisphenol-a.org/about/bpa-myths/bpa-accumulates.html

alexnharvey said:

Yes, in general but they don't metabolise BPA similarly.

http://www.bisphenol-a.org/about/bpa-myths/bpa-accumulates.html

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Problem about your source is that it appears to be sponsored by the trade association of producers of BPA... kind of like a lead mine saying "lead isn't really that bad for you."

The main point of that website is that there isn't enough data to be sufficiently sure that it is bad for you. A very similar approach taken by most companies who argue against EPA or FDA regulation.

In your defense however, the CDC takes a similar approach:
http://www.cdc.gov/biomonitoring/BisphenolA_BiomonitoringSummary.html