advantages/disadvantages of kettle mash tun

[Lunkerking]

So I am currently doing all grain brewing and my setup is using the cooler mash tun. I frequently mash in, and leave the house for an hour to go run or run an errand. Or even setup the mash when I’m home for lunch and finish when I’m home from work a few hours later.


I can see that the cooler I bought (fermenters favorite) is starting to bow out and I figure its only going to be good for another year. So basically I'm thinking that cooler mash tuns are not a long term solution unless you want to buy/build one every 5 years.


Maybe an obvious answer, but if I go to a kettle mash tun, I will have to apply heat to keep it at its mash temp? So I am hesitant to go down that road as I need to buy/build a new burner and get a kettle to use as a mash tun. Additionally, I would not want to leave the house while I have heat being applied to the mash.


Am I seeing this correctly? Thoughts?


Thanks for any advice.

 

[Hwk-I-St8]

Pretty much. I wish someone would come up with a SS insulated kettle that you can boil in. Then you could do what I do with one vessel. I mash in a cooler with a bag, then transfer to a kettle to boil.

In an uninsulated kettle, it will drop temp too quickly to mash w/o heat. Some people have had good luck with temporarily insulating the kettle...sleeping bags, winter coats, reflectix, etc. With adequate insulation, it should perform as well as a cooler and then the insulation can be removed for the boil.

The other issue with a non-insulated kettle is that it's not as simple as just adding heat. You have to have a feedback loop so that the heat is controlled by the temp of the mash. Further, you really need to recirculate the mash if you're adding heat to ensure accurate temp readings and consistent temps throughout the mash. Now you need an outlet, in inlet at the top for wort return and a pump for your rig. RIMS and HERMS are two solutions for this in a multi-vessel setup, and a recirculating BIAB is the single vessel answer.

The other thing to consider, if you don't mind your process, but the cooler is failing, is that 5 years for $30 cooler is a pretty good return on investment. As far as setting up a new cooler, if you do MIAB like me, it's just a matter of removing the hardware for the drain from the old cooler and installing it on the new one. That's not much time or money to keep going the way you are.

For me, I want one vessel to speed setup, tear down and cleaning. Plus I want the convenience, control and efficiency of electric. I plan to build my own recirculating electric MIAB (except with a SS "bag") sometime in the next year.

 

[JONNYROTTEN]

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The other issue with a non-insulated kettle is that it's not as simple as just adding heat. You have to have a feedback loop so that the heat is controlled by the temp of the mash. Further, you really need to recirculate the mash if you're adding heat to ensure accurate temp readings and consistent temps throughout the mash. Now you need an outlet, in inlet at the top for wort return and a pump for your rig. RIMS and HERMS are two solutions for this in a multi-vessel setup, and a recirculating BIAB is the single vessel answer.

This isn't true at all.
I BIAB I dont recirculate or have a feedback loop (whatever that is) I have an electric setup but dont even use it during the mash. I mash in a little warm to compensate for the temp drop from the grain, say 156, mash in and temp drops to around 152ish. I cover the pot and it retains the heat for at least a half hour and then begins to drop ending around 147 usually after an hour. They say most or all of the conversion happens within a half hour or less anyway. I been doing this for the last 5 years with endless great beers under my belt. I give it a stir once or twice throughout the mash also. Brulosophy did a test with mash temps like 148 to 175 or something crazy and noone could tell the difference in beer. I think exact mash temp arent a major concern in homebrew.

I do 10 gallon batches though so around 15 gallons in the mash. I'm sure the larger volume helps maintain more stable temps.

 

[Hwk-I-St8]

This isn't true at all.
I BIAB I dont recirculate or have a feedback loop (whatever that is) I have an electric setup but dont even use it during the mash. I mash in a little warm to compensate for the temp drop from the grain, say 156, mash in and temp drops to around 152ish. I cover the pot and it retains the heat for at least a half hour and then begins to drop ending around 147 usually after an hour. They say most or all of the conversion happens within a half hour or less anyway. I been doing this for the last 5 years with endless great beers under my belt. I give it a stir once or twice throughout the mash also. Brulosophy did a test with mash temps like 148 to 175 or something crazy and noone could tell the difference in beer. I think exact mash temp arent a major concern in homebrew.

I do 10 gallon batches though so around 15 gallons in the mash. I'm sure the larger volume helps maintain more stable temps.

OK - I'm agree that my point is only relevant if you want a mash temp stable within a degree or two.

The value of a consistent mash temp, of course, depends on the brewer. Brulosophy's experiment notwithstanding, I'll continue to pursue a stable mash temp and will mash different beers at different temps. I'm pretty sure I'm not alone in this. I do realize that I have a certain compulsion to be very precise in my approach to brewing (and most things I do).

 

[Kharnynb]

I used to have a basic stovetop kettle which held 8 gallons, doing a sparge with any water not able to fit during the mash.

with a decent, old duvet as insulation, you will lose about 1 degree celcius per hour if you wrap it well.

water is amazingly good at holding temperature, even with rather basic insulation.

 

[madscientist451]

Advantage of kettle mash tun: Its metal, won't wear out and won't need to be replaced.
Disadvantages: Its metal, so it will loose heat fast. You can insulate using and old coat of spend $ for special insulation. I've been using a round cooler for years and isn't showing any signs of failure, but when it does I'll probably just get another round cooler.
If I had an extra $350 laying around, I'd get a SS insulated mash tun, something like this:

https://www.chapmanequipment.com/collections/mash-tuns/products/10-gallon-thermobarrel

 

[Hwk-I-St8]

I was really excited about the Chapman insulated kettle when I first saw it, then realized you can't heat it. It's a valid replacement for a cooler mashtun (though pricey when you can get a cooler for $30), but in a typical mash/sparge/boil setup you still are stuck with a 3 vessel system.

I'm not sure what the recirculation port is for. If you're not heating the wort, I would think it would cause the temp to drop (just my intuition). If you are heating the wort (RIMS, for example), you don't need the insulation.

If you could heat that, it would make a great BAIB rig with a utah biodiesel SS mesh basket and a 5000 watt induction burner.

The process could be:
Heat the mash water in the tun with the induction burner
dough in
seal it up and go do something else for 60 mins
hoist out the mesh basket - compress if desired
Fire up the induction burner to boil

Just the basket and kettle to clean at the end.

 

[seatazzz]

You can also use an immersion chiller in your HLT as a heat exchanger, but I wouldn't recommend leaving your house while a burner is going. I don't even leave my pump running on my setup if I have to run to the store.

 

[ESBrewer]

U could also build your own insulation around the kettle, won't be difficult at all. Make it removable if u want to use the mash tun kettle for boiling purposes. I used insulation panel and urethane foam that is heat resistant up to 90°C. If the kettle is large (> 2 gal) and rather full of mash, it will be able to hold even temperature for an hr, even 2 hrs without additional heat.

 

[LostHopper]

I brew outdoors in a single vessel/kettle. I insulate my BIAB kettle (10.5 gallon) with a homemade but well-fit Reflectix coozy and a sleeping bag. If it's breezy which is most everyday, I throw a tarp over the whole thing. I lose a couple of degrees over an hour but I don't uncover it or add heat during that hour. I don't see maintaining mash temp in a kettle to be much of a challenge. I've got plenty of other brewing challenges but that's not one.

 

[mtbr_brewer]

This isn't true at all.
I BIAB I dont recirculate or have a feedback loop (whatever that is) I have an electric setup but dont even use it during the mash. I mash in a little warm to compensate for the temp drop from the grain, say 156, mash in and temp drops to around 152ish. I cover the pot and it retains the heat for at least a half hour and then begins to drop ending around 147 usually after an hour. They say most or all of the conversion happens within a half hour or less anyway. I been doing this for the last 5 years with endless great beers under my belt. I give it a stir once or twice throughout the mash also. Brulosophy did a test with mash temps like 148 to 175 or something crazy and noone could tell the difference in beer. I think exact mash temp arent a major concern in homebrew.

I do 10 gallon batches though so around 15 gallons in the mash. I'm sure the larger volume helps maintain more stable temps.

As a data analyst with a strong statistics background I have to mention one thing. While, I do LOVE brulosophy and think it's an incredible source of information. He is leveraging extremely small sample sizes (albeit experienced samples). So I'm not terribly surprised he rarely finds significant differences when he polls 20 people. Research and literature support that in most experiments a sample size of at least 30 is required to identify truly stable significance values. Granted, I'm no expert on the experimental design of tasting, I would like to see larger sample sizes (recognizing that's difficult).

That being said, I do find his discussion on mash temperature compelling in the sense that so few were able to correctly identify the beer with a higher FG. Nonetheless, I would think any pro-brewer would argue that mash temperature has a marked impact on flavor. Not only should it impact flavor and body, it can also impact the ability for the wort to absorb the oils from hops.

As far as the discussion, I use a keggle in my e-HERMs setup and would be leery of allowing that to sit unaided for the 60 - 90 minute mashes I usually run. I think you would definitely see a dramatic temperature loss. I actually constantly recirculate the wort through the HERMs coil and back onto the mash to maintain temperatures. I may be a little more risky, or confident, in my setup but I usually leave the system to maintain temperatures (pumps running, heating element on, pid on, etc.) while I walk the dog or tend to other things in the house. However, I do see a 2 - 3 degree difference between the HERMs vessel temperature and the mash tun, just from heat loss in the hoses and mash tun. Even I am trying to get this under control as you could see how you would essentially be mashing a two separate temperatures (there is a discussion on this in the electric brewing forum right now). However, I question the impact of a couple of degrees difference (especially consider brulosophy tasting findings, notwithstanding the statistics).

I don't have any information on how well the Chapman or SS Brewtech mash tuns hold temperature, but I'm looking into a removable insulation wrap to bring those two values closer together. I would say definitely invest in some type of insulation if you move to a kettle as a mash tun, even if there is some question on the true impact on beer flavor.

 

[Lefou]

When I first started AG brewing it was using the Igloo 10gal cooler. Mash temperatures would drift more than desired, so I looked for an alternative way to maintain stable temps and step mash without heated water infusions.

Most of my batches are 5gal or lower, so the decision was made to go with an ANVIL 7.5gal SS kettle. All the fittings are 304 stainless so there's no chance of metal leaching with cheap-@$$ brass. Mashing is done on a natural gas stovetop and the modified stainless false bottom I use was intentionally bought for the Igloo and fitted to the ANVIL kettle because the bottom diameters are nearly identical. Using an ANVIL steel kettle allows direct heat to be applied so I can step mash with a reduced chance of scorching. The induction capable clad bottom distributes heat well, so mash temps drift very little, staying within my preferred range of 145F-152F very easily on low heat. The kettle is supplied with a nice thermometer so monitoring temps is easy without opening the lid..

This method saves me the cost of a propane tank and burner but requires a second boil kettle. The second kettle is a 5gal SS single-walled kettle taken from a Brewers Best kit. It heats quickly and cools fairly well. I've literally put this cheaper steel pot into snowbanks to cool, then walked away for an hour or two to go shovel during our fourth and latest Nor'Easter of March here in NJ.

 

[Hwk-I-St8]

Wait, you're acceptable range of temps for the mash is 145-152 and you couldn't stay in that range with a cooler mash tun? I use a 50 Q rectangular cooler and I might drop 2 degrees in an hour. I've been putting a piece of foil over the top of the mash and it's less than that.

 

[soccerdad]

If you are brewing indoors and you have a beach towel / duvet / sleeping bag / old coat to throw over the kettle, you will lose almost no heat in 60 to 90 minutes.