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General Category => All Grain Brewing => Topic started by: ckpash88 on November 27, 2012, 02:57:34 AM

Title: Kettle Mashing Question
Post by: ckpash88 on November 27, 2012, 02:57:34 AM
So I brewed on thanks giving with my new set. It's a direct fired Boilermaker with a pump to recirculate during mashing.

The problem I was having I think were really bad hotspots. I would read the Brewmometer on the side and it would dip to 140 degrees on the dial the. I would put a thermometer in the mash and it would say 160.

When the Brewmometer would say 140 I would put the heat on and stir then in a couple of minutes I would bring it up to 152 my target temp.

Should I be stirring the mash almost all the time and if so should I be running the pump to recirculate while doing this?


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Title: Re: Kettle Mashing Question
Post by: bluesman on November 27, 2012, 03:15:17 AM
Do you have a false bottom?

I use the Blichmann kettle for my RIMS. I heat/recirculate using a false bottom with a moderate flame (KAB4 burner) and get some temperature gradients in the tun, but usually +/-3 degrees during the heat/recirculate without stirring. Stirring the mash should only be necessary after the initial infusion and upon sparging.

How do you infuse and/or recirculate your mash liquor?
Title: Re: Kettle Mashing Question
Post by: a10t2 on November 27, 2012, 03:19:13 AM
Have you calibrated the thermometers?
Title: Re: Kettle Mashing Question
Post by: hopfenundmalz on November 27, 2012, 12:33:14 PM
Sean has one obvious point, calibrate your instruments. I check the thermometers in my vessels vs the thermopen. The pH meter goes through a calibration with calibration solutions. Refractometer is checked with distilled water. And so on.

The pump return on my system is just the hose submerged under the wort. I give the mash a good stir to even out the temp.

Title: Re: Kettle Mashing Question
Post by: ckpash88 on November 27, 2012, 01:25:17 PM
I calibrated my equipment before i started both of my thermometers and brewmometer are the same.

I also have a false bottom as well in my brew kettle.

I infuse the first step which was like (i am estimating i don't have my recipe in front of me) 4.25 gallons of 169 degree water to 13.5 pounds of grain. I then stirred for a moment to get it mixed up then turned on my pump to recirculate.

After about ten minutes i would have to stop the pump (if i didn't stop the pump i would lose prime and fight that for a while) and stir to get the heat distributed more evenly.
Title: Re: Kettle Mashing Question
Post by: dcbc on November 27, 2012, 02:11:48 PM
I would suggest taking your temperature somewhere in the return loop to the kettle and keep the recirculation rate fairly quick (but not so fast that it sticks).  On my setup (direct fired rims with 20 gallon kettle and false bottom), I keep the flame low, recirc with the valve on the high output march pump about 1/4 open, and take the temperature with a probe on the output side of the pump.  My temps are pretty consistent between my controller, my kettle thermometer, and the handheld thermometer I use to randomly check the mash temps and wort return.  I use a piece of flexible/adjustable tubing from brewhardware.com as my wort return.  I place it just beneath the surface of the mash toward the side.  There is a little whirlpooling of mash liquor, but minimal aeration. 
Title: Re: Kettle Mashing Question
Post by: dean_palmer on November 27, 2012, 02:52:54 PM
My mash tun is also a direct-fire keggle with a RIMS tube and a false bottom. Mostly 10 gallon batch sizes. I do stir for a while as the temps stabilize, and a few times during the mash session to even them out. No matter what you do there will be temp differences, especially when the outside temps are cold, and there is nothing wrong with gentle stirring of the mash every 15 minutes. If you were using a well insulated vessel it would be even more stable, but with an uninsulated stainless vessel there will always be a bit of variation. Nothing wrong with some stirring, if there were, the pros wouldn't have mash rakes running. Chances are if you did nothing you would still get acceptable results due to the average temps in the main body of the mash.
Title: Kettle Mashing Question
Post by: ckpash88 on November 28, 2012, 02:30:21 AM
Two questions.

Should I have the pump recirculating wort while I am stirring?

Would my best bet on monitoring mash temp be right at the kettle valve? If my thinking it right that should be the hottest area in the mash.


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Title: Kettle Mashing Question
Post by: ckpash88 on November 28, 2012, 02:34:00 AM
I know I didn't mess up my last batch bc the airlock was going crazy. I am just not sure if I hit my target temp to get the right gravity... I guess I'll know after it hits fg.


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Title: Re: Kettle Mashing Question
Post by: dcbc on November 28, 2012, 03:39:35 PM
Two questions.

Should I have the pump recirculating wort while I am stirring?

Would my best bet on monitoring mash temp be right at the kettle valve? If my thinking it right that should be the hottest area in the mash.


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I think there are multiple schools of thought on probe/thermometer placement.  The valve is probably fine.  Mine is about in the middle of my loop, about 3 feet of silicone hose and one pump from the kettle outlet.  This is about half way between the heat source (direct fired) and the mash liquor return in the kettle.  Once everything settles in, the probe in the loop is reading the same as both the kettle thermometer (mid mash) and the thermometer I can stick in the wort stream at the return or in several spots at the top of the mash.  So, the answer is that it probably doesn't matter too much.  By having it mid stream, I'm chancing that the mash liquor below the false bottom where heat is being applied might be slightly hotter the second or two it's being heated before leaving the mashtun and recirculating across the probe that controls the flame.  But that's not enough of a variation to worry me.  My recirculation rate is pretty quick.  So things are constantly moving.

As for stirring, you shouldn't have to if you are recirculating your mash liquor and you have a return line placed in a way that causes that mash liquor to flow fairly evenly throughout the mash.  The quick paced recirculation of the mash liquor coupled with a low heat source will help you avoid scorching and the correct placement of the return line helps to keep the mash temperature uniform.  By stirring, you are disturbing the mash bed, making it harder for the mash liquor to clear, and could possibly increase the chances of a stuck mash.

This is, of course, based on my system.  So your mileage may vary.

I should also add that my direct fired RIMS is automated.  So I'm not doing anything but letting the mash settle for about 10 minutes, starting my pump, slowly at first, then increasing flow to a pretty brisk rate, then punching in my temperature on the controller, and letting the controller do all of the work.  Manually turning the flame off and on sounds like a lot of work and is probably going to lead to some temp swings.  Once my temperature has settled in, the flame-ons don't tend to last longer than a second or two every 30 seconds to a minute. 

Some good insulation for the kettle might be a better bet until you decide to automate the RIMS.  Some closed cell foam (gym mat) and aluminum tape did just fine for my kettle for an hour mash as long as I wasn't recirculating.  It's not the prettiest thing, but it works.

Good luck.
Title: Re: Kettle Mashing Question
Post by: dean_palmer on November 29, 2012, 06:15:44 PM

Should I have the pump recirculating wort while I am stirring?

Yes

No reason to shut it off when you stir unless what you are doing affects the pumps. Mine work fine when stirring the mash.

As for clearing of the wort, that will happen with a few minutes or less of recirculation, so just don't stir near the end of the process.

There is really no downside to any normal (not excessive) stirring of the mash. In a non-heated setup where you lose heat by opening the lid, stirring and heat loss can be a concern, but for a heated mash system it isn't.

As for the right place to take the temp, there are lots of places you could measure, but what matters is the average temp of the mash itself. Don't obsess, but do take all the tips provided for insulation as that is your best chance to keep an even temp in a metal vessel. Go low-tech like a blanket or removable foam wrap. Don't attach anything, you'll regret it later, trust me, done a lot of ideas there. Just something you add after the mash and recirculation is stable, and something you can remove at the end of the mash session.
Title: Re: Kettle Mashing Question
Post by: AleForce on November 29, 2012, 06:51:41 PM
What size of tubing are you using for recirculating?  3/8" , 1/2" ?   

When I was using a cooler for my mashtun, I was using 3/8" tubing... When I switched to using Blichmann's I had to go to 1/2" tubing to get a better flow rate coming out of the kettle, which meant the pump wasn't having problems...
 
Title: Kettle Mashing Question
Post by: denny on November 29, 2012, 07:46:01 PM
What size of tubing are you using for recirculating?  3/8" , 1/2" ?   

When I was using a cooler for my mashtun, I was using 3/8" tubing... When I switched to using Blichmann's I had to go to 1/2" tubing to get a better flow rate coming out of the kettle, which meant the pump wasn't having problems...

Me?  3/8.
Title: Re: Kettle Mashing Question
Post by: bluesman on November 30, 2012, 03:31:20 AM
What size of tubing are you using for recirculating?  3/8" , 1/2" ?   

When I was using a cooler for my mashtun, I was using 3/8" tubing... When I switched to using Blichmann's I had to go to 1/2" tubing to get a better flow rate coming out of the kettle, which meant the pump wasn't having problems...

I use 1/2" high-temp silicone for my RIMS.
Title: Kettle Mashing Question
Post by: ckpash88 on November 30, 2012, 03:53:08 AM
I used 1/2 inch bc I had it sitting around.


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Title: Re: Kettle Mashing Question
Post by: smkranz on November 30, 2012, 04:32:42 AM
With my Blichmann gear (15 and 20-gal kettles and false bottoms), it took me a good 6-8-10 batches (I'm a slow learner!) before I figgered out what others here recommend, i.e. use a constant and fairly healthy flow rate, and constant but very low heat.  Blichmann button-louvered false bottoms seem to take a good bit of flow without getting stuck.

I was constantly messing with the pump flow, thinking slower was better, and actually created stuck sparges because (I theorize) if there is heat underneath the FB but little to no wort movement, that wort will boil, bubble up, let grain under the FB, and air/grain will get trapped in the pump.  When you see the pump sputtering and seizing with trapped air and grain (as I have through numerous frustrating batches), it leads to a stressful afternoon debating whether you need to get all that mash out of there and start over...ugh.

Now, I mash in a little low, turn on the pump, stir thoroughly at the beginning while the mash temp is rising, and then leave it alone.  Make sure there are a couple inches of wort above the grain bed during constant recirc.  Very low flame on a Blichmann burner.  My return is a silicone tube that rests just below the liquid surface with the help of a couple of floats (from the Blichmann Autosparge without the Auto  ::) ).  When I make temp adjustments, I also tend to open the pump a scooch as well just to bump up the flow rate across the heat source.  The hotter wort comes from underneath the false bottom and is deposited onto the top of the mash.  It takes a little time to make its way through the bed, and then I back off the burner (or shut it off) when I'm actually a few degrees short of target...the heat at the top will make its way through the bed to even out.  I would rather under-shoot and come up gradually.  If it starts to drop a degree or two, turn the heat back on, but leave the pump run continuously.

A pair of Blichmann control modules on a Tower of Power is a couple of Christmases away, it seems.  Until then, I think I've got my stuff dialed in fairly well.
Title: Re: Kettle Mashing Question
Post by: dcbc on November 30, 2012, 03:45:38 PM
What size of tubing are you using for recirculating?  3/8" , 1/2" ?   

When I was using a cooler for my mashtun, I was using 3/8" tubing... When I switched to using Blichmann's I had to go to 1/2" tubing to get a better flow rate coming out of the kettle, which meant the pump wasn't having problems...

I use 1/2" high-temp silicone for my RIMS.

That's what I'm using as well. 


A pair of Blichmann control modules on a Tower of Power is a couple of Christmases away, it seems.  Until then, I think I've got my stuff dialed in fairly well.

These are among my favorite purchases.  They do a fantastic job.  I'm running the modules without the tower, flow meter, pump mount, etc.  I already had my pump mounted and, the flow meter with auto shutoff, while nice, wasn't worth the extra $500 to me.  I mounted mine on an articulating CRT TV wall mount that is bolted to my stand.
Title: Re: Kettle Mashing Question
Post by: bluesman on November 30, 2012, 05:28:46 PM
With my Blichmann gear (15 and 20-gal kettles and false bottoms), it took me a good 6-8-10 batches (I'm a slow learner!) before I figgered out what others here recommend, i.e. use a constant and fairly healthy flow rate, and constant but very low heat.  Blichmann button-louvered false bottoms seem to take a good bit of flow without getting stuck.

+1

I also went through several batches before I started to gain some confidence with my Blichmann equipment. Steady flow and low heat are recommended. I have to say that once you master this process, it allows one to manipulate the mash much easier and it's so much fun and easy to use.
Title: Re: Kettle Mashing Question
Post by: dean_palmer on November 30, 2012, 06:00:54 PM
1/2" ID silicone for everything. If you are using a March pump you should be using at least the ID of the pump inlet, and that's 1/2".
Title: Kettle Mashing Question
Post by: bluesman on December 02, 2012, 04:28:33 AM
+1

This will allow for less restriction and overall better flow through the pumps and hoses.
Title: Kettle Mashing Question
Post by: ckpash88 on December 02, 2012, 09:00:11 PM
Well I took my first reading of the batch made on the new equipment the OG was 1.076 and the final was 1.034 should have been 1.012-1.018. So I missed my target I think I was on the hot side. I sampled it and it was a little thick but tasty.


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Title: Re: Kettle Mashing Question
Post by: oly on June 26, 2013, 03:14:16 AM
Reviving an old thread here, didn't see this particular question so here goes.

I wish to direct-fire kettle mash a wit (50% unmalted wheat, 50% pale malt) while recirculating with march pump. I have two choices for kettle: a polarware with false bottom, or a smaller kettle that has only a bazooka screen.

I gather from the posts above that false bottom works for this (does not get clogged).  I'd prefer to instead use the small kettle with bazooka screen (and keep the bigger one for my boil). Does anyone here have experience recirculating kettle mash using only bazooka screen? Will it clog?
Title: Kettle Mashing Question
Post by: a witty man on June 26, 2013, 11:54:03 AM
Reviving an old thread here, didn't see this particular question so here goes.

I wish to direct-fire kettle mash a wit (50% unmalted wheat, 50% pale malt) while recirculating with march pump. I have two choices for kettle: a polarware with false bottom, or a smaller kettle that has only a bazooka screen.

I gather from the posts above that false bottom works for this (does not get clogged).  I'd prefer to instead use the small kettle with bazooka screen (and keep the bigger one for my boil). Does anyone here have experience recirculating kettle mash using only bazooka screen? Will it clog?
I think direct firing with a bazooka tube is a bad idea. With a false bottom you have the flame heating liquid, with a bazooka tube I think you'd have a greater chance of scorching the grain that is sitting on the bottom of the   kettle.

I'd go with the polarware, and definitely throw some rice hulls in this one. All that wheat will get real gummy.

Title: Re: Kettle Mashing Question
Post by: oly on June 27, 2013, 12:40:34 AM
Good point, hadn't thought about that. I guess it's the polarware. thanks.