Plastic Keg Mash Tun

[frankstoneline]

I searched, apologies if I missed something.
A buddy of mine is a bar manager and has a plastic keg from a company they no longer deal with and who wont pick it up so i have the opportunity to acquire a plastic keg and was thinking it might make a good Mash tun but I'm not sure what kind of temps it would be rated to and/or if I'd run into any issues with using it. I figured I'd put in a valve bulkhead and maybe a false bottom and insulate it as much as possible.
Thoughts?

 

[MalFet]

Any markings to indicate the kind of plastic or how/where it was manufactured?

 

[PurpleJeepXJ]

Barrels like that in bars are typically sanitizers so look on the bottom for markings and then Google those.

 

[frankstoneline]

I'll be picking it up tomorrow afternoon and can give more information then, he said it's a beer keg that was emptied but the distributor changed and then no one would pick it up, so I assume it's food safe. my concern is whether it's materials will hold up to mash temps though 170*f isnt something I worry too much about.

 

[MalFet]

I'll be picking it up tomorrow afternoon and can give more information then, he said it's a beer keg that was emptied but the distributor changed and then no one would pick it up, so I assume it's food safe. my concern is whether it's materials will hold up to mash temps though 170*f isnt something I worry too much about.

Physically holding up is important of course, but for me the bigger question would be if it will start leeching chemicals at 170F.

 

[frankstoneline]

Physically holding up is important of course, but for me the bigger question would be if it will start leeching chemicals at 170F.

This was what I meant by "hold up" sorry if i wasnt clear. Are there certain types of food grade plastics that are especially not safe at mashing temps? I suppose I should google some sort of table...

Edit:
I just looked up food grade plastics, and it seems like most of the common food grade plastics are rated to 160*f, which would be ok for general mashing (maybe) but not for raising temps to mash out, however PVC is rated to 160 and I've seen people using PVC parts in mash tuns and also using number 2 HDPE water coolers which are also only rated to 160.

 

[buzzkill]

is it plastic? or is it SS coverd in plastic?

 

[IrregularPulse]

is it plastic? or is it SS coverd in plastic?

This is a good point. Look inside when you get it open. You may find it to be SS inside. I couldn't imagine a production brewery risking a keg of beer with a plastic lined keg.

 

[MalFet]

There are two kinds of all-plastic kegs commonly used commercially. The "one-way" kegs are relatively flimsy, but the reusables are pretty solid. I've never seen plastic covered SS, but I wouldn't be surprised if it exists.

There is no great answer for temperature ratings, and even with the plastic type known it can be hard to know its specific ratings. Not all HDPE, for example, is created equal. Your best bet is to figure out the manufacturer and then to ask them if their plastic kegs are food safe at 170F. If you can't figure that out, it ultimately comes down to how you feel about plastics...some people don't like using heated plastics due to all the BPA, etc. stuff, but some people feel the hype is overblown. The science is far from conclusive at this point either way.

Personally, I'd be okay using one of the reusable kegs at 170F, but less comfortable using one of the disposables. Higher quality plastic tends to be less vulnerable to chemical leaching.

 

[rekoob]

This interests me... about a year or so ago I also got a keg like this, kinda the same way. My intensions were to use it for something but I never even vented it and took the middle out to see what’s inside. I have it sitting in my shed and think I will do that. I was on another forum then and it was suggested that it could be rubber coated SS. It does seem to be a very hard plastic or even some type of hard rubber. it is about the same weight as my other kegs and about the same size. The hook up area is SS. I was thinking a fermenter down the road. Now I am curious as to what is inside this thing.

 

[Mose]

I have two kegs that are SS covered in hard black plastic. They are my two vessles for a Brutus 20 electric build. I cut the bottom and set them "upside down" and use them in a bottom drain set up.

All you need to do is cut away the plastic with a hole saw and drill.

There are a couple threads on here where guys have pulled the plastic shell off and attempted to weld legs on to work as a kettle with a burner vice electric, but I don't remember the end result or if it was posted.

Good luck.

 

[frankstoneline]

Update:
Picked up the keg, bled the pressure, drilled a hole in the top to see if it was lined, not lined so I chopped it with a jigsaw, and left enough of a lip to use a stainless lid I have lying around. Going to try and insulate it and put in a bulkhead when I have some more time/money. The keg appears to be relatively thick plastic, so not one of the flimsy jobs and seems like it will fit the bill nicely as a mash tun. now begins the planning for insulation, bulkhead etc.

 

[Budzu]

If it is from PlasticKegsAmerica, then it can take temps. They state that they have held up against stainless keg cleaning routines (which typically include very hot alkaline cleaner and steam). If it can take that treatment, then a mash won't hurt it.

 

[rekoob]

I just took the center out of mine and after rinsing it out, looked inside. It is plastic coated stainless. it's my fourth keg so I never intended to use it in my build, still leaning towards using it as a fermenter or? just not sure what to do with it but I guess that its stainless on the inside gives me more options.

 

[frankstoneline]

I just took the center out of mine and after rinsing it out, looked inside. It is plastic coated stainless. it's my fourth keg so I never intended to use it in my build, still leaning towards using it as a fermenter or? just not sure what to do with it but I guess that its stainless on the inside gives me more options.

If you have the capacity I like the idea of using it as a fermenter, especially if it's stainless. If I get my hands on another one that was my plan.

 

[RegionalChaos]

I bet the thick plastic will insulate pretty good... As a fermenter that might be a bad thing..

 

[frankstoneline]

I bet the thick plastic will insulate pretty good... As a fermenter that might be a bad thing..

How thick is the plastic on the steel lined plastic kegs?

 

[frankstoneline]

update!
finally made this thing, here's a crappy pic, better soon.