MASH TUN; what is it?

[Gato]

I thought a mash tun was the same thing as a brew kettle: used to mash grains either by step or at around 152 degrees F; but I see designs made out of plastic coolers...what is with this?

How do you mash grains in plastic? Do you just use the cooler to rest or sparge the grains; or just to filter the mash; or is this a means of using electric heating elements rather than propane?

Does the plastic impart a plastic flavor?

I searched this forum (including Palmer) and found some great cooler designs but no clear explanation as to why you would use an Igloo for mashing.

Obviously; I have missed something obvious. Thank you for your understanding.

 

[el_caro]

I thought a mash tun was the same thing as a brew kettle: used to mash grains either by step or at around 152 degrees F; but I see designs made out of plastic coolers...what is with this?

How do you mash grains in plastic? Do you just use the cooler to rest or sparge the grains; or just to filter the mash; or is this a means of using electric heating elements rather than propane?

Does the plastic impart a plastic flavor?


I searched this forum (including Palmer) and found some great cooler designs but no clear explanation as to why you would use an Igloo for mashing.

Obviously; I have missed something obvious. Thank you for your understanding.

You do not heat the liquid while it is in the mash tun. The plastic coolers are popular because it is easier to maintain the required mash temperature for the prolonged period of time without applying heat. The plastic container does not appear to produce any plastic flavor although I have never used one.
A brew kettle on the other hand has to be able to withstand heat as the sweet liquor is heated and boiled in it. Some home brewers are now using BIAB techniques and doing the mash and boil all in one vessel (aluminium or stainless steel).

 

[OHIOSTEVE]

you are mistaking a mash tun for a boil kettle. The mash tun is the vessel that you mix the grains and water in to extract the sugars from the grains. This is done at various temperatures for different desired results and those temps need to be held for an hour or more. The reason an igloo is used is that it is an insulated vessel that WILL hold its temperature for an hour or more. Once you have " MASHED" the grains you drain off the sweet wort into your BOIL KETTLE and leave the spent grains behind ( that is whay there are false bottoms and or manifolds or braids used) to actually cook the wort down and add the hops etc.

 

[squirrelly]

Depending on the design you wish to build really depends on the materials used to make the mashtun.

My first mashtun was the old rectangular Coleman cooler with a PVC manifold built into it. It worked really well, and had no issues imparting any strange flavors. I later kept the same design, but constructed the manifold out of copper only so I could solder the joints, and not have so many leaks in the system. That mashtun cost me around 75.00 to build.

I now have a stainless steel kettle with a false bottom, a temp control switch, and a float switch. This setup was built by more beer as part of the fully digital B-1100 system.

With the plastic container method, of course you do not want to apply direct heat under your mashtun. Usually brewers will set these up in a gravity fed three tier system heating the water to normally 10-15 degrees hotter than their desired mash in temps. This water is heated in the hot liquor tank, and introduced to the mashtun at dough in. My setup had a manifold screwed to the lid. This allowed for silicone tubing to be run from the ball valve on the HLT as to act as a closed transfer, and loose much less heat while filling the mashtun. The cooler should keep your temp pretty close to your target rest temp for 60 min. Mine would loose about 1.5 degree every 30 min.

With the stainless option you can apply heat directly under your mashtun leaving your HLT solely for sparge water. Of course you never want to apply heat directly once you have added grains to the grist, so this is best for brewers with a pump to do a recirculation mash or RIMS system. Since the stainless pot won't typically hold heat as well as the insulated cooler, alternate means of keeping that desired rest temp must be used.

I hope this cleared up some of your confusion, and did not just add to it.

 

[Bobby_M]

 

[Gato]

OK, Thank you all! A lot of very high quality information to process on mash tuns and mashing temperatures. More questions coming. I guess the best way to insulate a stainless keg kettle is to find an abandoned building and get some old asbestos pipe insulation

 

[Rev2010]

Just wanted to add a point about the plastic question:

Does a plastic Coke bottle make your soda taste like plastic? - No
Does a plastic milk bottle make your milk taste like plastic? - No
Does a plastic fermenter (extremely highly used by home brewers) make your beer taste like plastic? - No

I don't know why anyone fears this. Not putting you down at all for questioning it, it's just that plastic vessels of all types are so common today and they wouldn't be if everything stored in them took on a plastic taste


Rev.

 

[Bobby_M]

Points taken, but non of those common plastic containers you mentioned are held at 155F for a hour. Plastic leeching is definitely temperature related.

 

[el_caro]

Points taken, but non of those common plastic containers you mentioned are held at 155F for a hour. Plastic leeching is definitely temperature related.

Whenever I have had a cup of hot tea (200°F+)in a plastic mug it always has a strange flavor.

 

[birvine]

OK, Thank you all! A lot of very high quality information to process on mash tuns and mashing temperatures. More questions coming. I guess the best way to insulate a stainless keg kettle is to find an abandoned building and get some old asbestos pipe insulation

I hope you were kidding about the asbestos. Just to be clear - don't use it.

I use a cooler as my MLT and wrap a fleece blanket around it to hold the temp. Before long I am going to get a pump so I can maintain the temp.

B

 

[Rev2010]

Points taken, but non of those common plastic containers you mentioned are held at 155F for a hour. Plastic leeching is definitely temperature related.

OK, if you want to go there... ever have hot tea, coffee, or hot chocolate out of a thermos? Nearly everyone has at some point and no one ever notes a plastic taste. Funny thing too because the coffee mug my firm gives the employees are plastic, one's similar to this:

No complaints of a plastic taste. Ever microwave a dinner in those plastic microwave safe dishes they come in, like a Swanson TV dinner or whatnot? No plastic taste there either. I'm sure there are several other instances in which hot foods/beverages are dispensed or held for an hour at hot temps in plastic containers but those are the first to come to mind.

*EDIT - btw, I'm not disagreeing with you that there can be various chemical compound leakage from plastics, just that the whole taste thing is severely blown out of proportion.


Rev.

 

[el_caro]

My wife and I will not drink tea out of a plastic cup but that is probably all in the mind as we boil all our water in a plastic electric kettle with no off flavor.

 

[birvine]

My wife and I will not drink tea out of a plastic cup but that is probably all in the mind as we boil all our water in a plastic electric kettle with no off flavor.

Tea is best in fine china I find.

B

 

[el_caro]

Tea is best in fine china I find.

B

I totally agree with you and that is how we drink it.

 

[squirrelly]

I never really thought it was a "plastic taste" everyone was afraid of when it came to brewing. I refuse to use plastic for one main reason, and it has nothing to do with taste. This reason is sanitation. Plastic vessels are so impervious to nicks, scratches, and bumps that it is impossible to keep it sterile. When I used plastic vessels for fermenting it seemed I was replacing buckets every 2-3 months. This holds true for the rest of my plastic equipment that came in contact with the boiled wort or beer as well.

Now for equipment that is going to be used pre-boil, I don't have a problem using plastic. For instance, my system is the single tier B3 1100, and to move wort and sparge water from one vessel to another I use silicone tubing. The only issue one might face using plastic pre-boil is the possible leeching of harmful chemicals out of the equipment. Honestly I'm not too worried about that. So long as my plastic gear does not read made in china I think I'll be fine. After all I still live in a house with asbestos around my hot water heater vent, knob and tube wiring, and lead paint in the walls. So far all is well

 

[el_caro]

Plastic vessels are so impervious to nicks, scratches, and bumps that it is impossible to keep it sterile. When I used plastic vessels for fermenting it seemed I was replacing buckets every 2-3 months. This holds true for the rest of my plastic equipment that came in contact with the boiled wort or beer as well.

I think you mean prone rather than impervious.

I only use plastic for FVs and have no issues with nicks and scratches. When you finish brewing just fill the FV with water with Sodium Percarbonate (Nappy wash) and let it stand for a few hours. The crud comes off easily with just a soft cloth wiping then rinse and store it away. Just starsan it and it is ready to go.. Take care never to put hard objects in the FV or use any harsh abrasive cleaners. They will last for years I have one that has done nearly a hundred brews and never an issue.

 

[squirrelly]

Yes indeed I did not mean to use impervious. That's what posting at work with 2 hours of sleep in 2 days will do to you.

I agree if great care is taken then buckets or any other plastic vessel for that matter will work just fine. The fact of the matter is I don't have time to wait for fermenters to soak between batches. This is why stainless conicals are the best for me. My wife and I brew 4-6 times a week typically 10-20 gallon batches at a time unless it's a pilot brew. As it stands now while one of us is doing the runoff into a fermenter the other is throwing star San in another fermenter and heating strike water. When I clean a vessel (or anything for that matter, I am quite OCD, and even have coffee cups numbered and circles drawn for proper items to be placed,) I get in there with an abrasive pad, PBW and hot water and scrub until every piece of debris is gone. Then I fill the whole thing with star San and let it sit until its ready to be filled with wort. I want to be able to swab the inside of the fermenter then plate the swab and see no living organisms.

 

[BradleyBrew]

its a large container where you have the capacity to mash up to 1 tun of potatoes