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Mashing/lautering in a kettle

I have a new toy for the next brew session: a Blichmann kettle with the lauter screen for mashing as opposed to using a cooler. Question: what major differences might I be overlooking with using a kettle vs cooler? The obvious answer is periodically turning on the burner to maintain temp. I also figure I will need to stir often when the flame is on to prevent overheating grain on the bottom. Anything else?

I would suggest that if you use direct heat to do a step mash to use a low flame and stir like hell. Other than that its pretty straight forward. I wouldn’t add heat to maintain temps. Just find a nice thick blanket to insulate it.

Thanks! Didn’t think about the blanket. One advantage is since I’m starting out at room temp with both water and grains, I can test pH without racing against the clock to avoid harsh tannin flavors.


Check this out.^
I added wet suit material on top of the bubble wrap. Temperature hold steady for the whole mash both 60 and 90 minutes mashes

[quote=“Bier brauer”]
Check this out.^
I added wet suit material on top of the bubble wrap. Temperature hold steady for the whole mash both 60 and 90 minutes mashes[/quote]
Good idea, where did you get the neoprene?

Jo-Ann fabrics is where I found it. The wife and I went in for something she needed and I asked the clerk if they can get it. They had a small roll left over from something. I think it is about 1/8 thick. I was checking out neoprene on line when I found it. The only draw back is neither the neoprene or bubble insulation likes heat. So, if you are going to fire up the burner, better take it off the kettle before you do or both will melt. When I mash I sandwich the wet suit material over top the bubble insulation on the kettle. The wet suit material has straps with plastic buckels that snap together to hold everything in place. You probably can do the same thing using a bungee cord. I took the neoprene to a guy who makes covers for cars and such. He stiched two pieces of material together and sewn the straps on. I cut and fit the material to fit the kettle before I took it to be sewn. It sure is nice to heat the strike water, add the grain, stir it up, put the lid and insulation on and kick back for a while. I also cut pieces of the bubble insulation to cover the lid plus I put a blanket on top. Hope this helps a little.

It does help, thank you. I remembered this morning that Walmart sells a closed cell foam sleeping pad in the camping dept. This should retain heat pretty well, and I’ve cut one up before, so I’m pretty sure I can tailor a suit for my kettle. Thanks!
OTOH, is it ok to add water and grains in at room temp, then bring everything up to 152 or am I asking for trouble? I thought it would be nice to dial in pH first. Anyone tried this?

I will be honest. I never heard of doing that, second if you can’t I don’t know the reasons why. I will only guess here. Maybe it will turn into a huge gum ball. I do know you want to add the grain to water, not water to grain. Again not sure why.
I am trying to get a handle on the water thing myself. I just bought water treating chemicals to change Ph. I will adjust the mash Ph after the grain has been in the pot for about 10 minutes. I know grain will effect the Ph and I don’t know which way I will have to go with the adjustment until the grain has been in the water a few minutes.
There are many amazing brewers on this forum who will give you (and I) solid answers to your questions. I wish I had the experience and knowledge to help you. Maybe one of these days perhaps.

The downside I could see is that the grains at the bottom of the kettle would be much much warmer than those near the top leading to harsh tannin extraction. I’m sure stirring would be key.

I think B’run Water software will give you the approximate adj for grain. Beersmith may do the same, I’m just starting to use it. Running a test on my new closed cell foam suit of armor for the mash tun now now. So far so good. I added a thick blanket for good measure… loss of 2 degrees, but I opened once to stir my test water. Which lead to another question: is stirring mash necessary?

  • Joe

Anytime I add heat to the mash I stir. I also use a march pump to recirculate the wort from beneath the false bottom back into the mash tun while heating. While I do that I stir to keep the heat consistent through the mash. If I do use the burner, I back it all the way down when I am within 5-8 degrees from my target temperature until it settles out, I still keep the pump going. I haven’t done a step mash for a long time. I just heat to my desired strike temperature, add grain, cover and let it sit. Like yourself, I find if I remove the lid the temperature drops. So if I do stir, it is at the end of the mash. If I plan a 60 minute mash I keep it covered for 57 minutes or so then stir. At the end of the mash I will again recirculate wort from below the false bottom back into the kettle to set the grain bed because I fly sparge.
I am just learning beersmith. B’runwater I don’t know how to use.
Good luck with your project. Hope it works as well for you as mine did for me.

Back to the O.P. How big of a kettle did you buy? I never used a cooler for mashing so I can’t compare between the two. I have a 15 gallon kettle I used to mash in, I had a huge air space between the grain and lid. I only do 5 gallon batches. I bought a 8 gallon kettle exactly like the 15. Now the air space is smaller and it seems to hold the temperature more steady. So I use the 15 gallon kettle for the HLT and the boil.
How did things work out for you?


I bought a 10 gallon Blichmann with the false bottom. I put my starter in the fridge last night after about 22 hours on the stir plate. I am brewing this afternoon, finalizing water additions with B’runwater now.

One thing about mash tun temperature - verify with a second thermometer; my Blichmann thermometer is prone to chilling the wort immediately surrounding it - case in point, it showed a temperature of 140f yesterday after about 75 minutes in a 90 minute mash. My Thermopen correctly displayed 153f at the same spot. Seems to happen mostly when it’s cold outside - so I think that the SS tun and the short stem create colder spots immediately around the outer edge and stem where it penetrates the mass. YMMV, just sayin, before you panic and hit it with external heat, double check and possibly just stir a little. Your thermal cover should do wonders to counter the problem I am mentioning.

Good luck with the new equipment!


Good point. Question about your thermopen, how long is the probe on it? I screw the thermometer into a boot that is welded into the kettle. I guess it sits a good 6 - 8 inches below the top of the mash. Can a thermo pen reach that deep?

I’ve read similar things from others with the Blichmann Brewmometer, but mine’s been pretty good. I’ve been careful not to let it get hot (always use the heat shield). That said, I’m paranoid enough about it to use my digi as well. Always within a degree, sometimes two.
As for the brew, I got a bit frustrated with trying to insulate my kettle, I had lost about 6 degrees with closed cell foam and a thick blanket wrapped around it. I thought “what good is using a kettle as a mash tun if you can’t put fire to it?” After all the top tier system and tower of power from Blichmann do just that, it fires the burner to keep the mash temp static. So I abandoned the thermal wrap and put it back on the burner, stirring while flame on. Got back up to 152 degrees and after sparging I checked my gravity readings, everything was set for me to hit my 1.062 OG target. I actually came in at 1.063. My efficiency was 70%, which I’ll take considering my temps went low, then my sparge water was only at 161 degrees when I dumped it in. Which leads me to a question:
I dumped the sparge water in, all at once and none too gently, created a bit of foam in the mash. Bad thing? What, if anything, does this do?
All in all, another exhausting brew day, one of these days I’ll be more organized and efficient! Oh, some misc notes:

  1. used a 10 gallon cooler filled with ice-water and a submersible sump pump connected to my immersion chiller as opposed to just using the garden hose. BIG time saver (20 min vs 120 min). (thanks Nighthawk)
  2. refractometers live up to the hype
  3. I still hate pH test strips. Maybe I will get a meter after all, but reading reviews on them gives me pause.

I have to say I tried using my kettle with false bottom for mashing, and it was a painful experience. I didn’t try to insulate it, because as you said “what good is a kettle if you can’t heat it?”. Instead I was turning my burner on and off constantly trying to get it to maintain temperature. And even with constant stirring, I would have the temperature jump around suddenly as a “bubble” of hot liquid burst up past the false bottom to overheat the mash.

In the end, I went back to using a cooler.

As for your question about mixing while cold, that is something that used to be pretty standard in brewing back when multiple rest mashes were needed. You will get much better hydration of the grain that way (no dough balls). But it is only really practical to do that if you have a directly heated mash tun or are planning to do decoctions.

Well, today I totally saw what you were experiencing. Temp shot from 151 to 161 extremely quick even while stirring. Bummer… hopefully I didn’t extract much harsh tannins. Temp would also read hot on the bottom of the kettle and perfect near the probe. Makes me totally rethink investing in that top tier system though! I believe I will also return to the cooler for mashing and use my kettles for heating water and boiling wort.

I have seen single induction burners, I wonder if one of those could be used with a temperature controller for a mash tun.

I know I’m joining the conversation a little late at this point, but I figured I would chime in.

I have only ever mashed in a kettle - my older 50l Italian kettle. Used to use it for everything, but now only for a mash tun. I actually do really like it.

I have enough volume in there for up to a 70l batch size, but I usually do 50l.

Originally I had planned to use it on a burner to add heat if needed - have not done that in years. If you want to change temps, I find it way easier just to add hot or cold water.

For insulation I just throw a blanket on there. I have always found that a good sized mash holds it’s temperature pretty well. When I throw a blanket or sleeping bag on top of that I rarely lose more than a degree over the course of an hour long mash.

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