Recirculating in Blichmann boilermaker MLT

sethhobrin · January 19, 2012, 3:50pm

So I got a 10g boilermaker for xmas. I have done 1 batch so far and right away I realized firing up my propane burner to heat up the mash to maintain mash temp will not work. false bottom absorbs too much heat and my wort will scorch…

so now my options are to somehow try and recirculate with a 4 qt contrainer that I use for vorlaughing or to buy a march pump and recirculate that way.

Does the container method work or am I just asking for trouble?

If I go the march pump route how difficult is it to maintain temps like this? do you just leave it on during the entire mash with very low flame? I assume drilling a hole in the lid or something like that would be necessary.

Right now I think I have 3/8 barb on my kettle should I be moving to 1/2" when doing a march pump?

Can anyone give me any tips or guidance on maintaining mash temp in a kettle like this?

cramer · January 19, 2012, 4:00pm

Just insulate it and you won’t have to apply any heat.

sethhobrin · January 19, 2012, 4:37pm

I was thinking the same thing but what about mash out? And with these wisconsin temps even in my garage I don’t think I can insulate it enough.

brans041 · January 19, 2012, 4:46pm

Mash in a cooler and use boilermaker as boil pot.
When mashing bring the pot inside.

Pots don’t make good mash vessels unless they are insulated, especially up here in the northwoods.

sethhobrin · January 19, 2012, 4:49pm

i already have a nice boil kettle. I was using a cooler before to mash…

sethhobrin · January 19, 2012, 4:52pm

I can probably insulate it fine so there is not much temp drop but I still need to be able to increase the heat to step mash or mash out without scorching the wort below the false bottom. that is the main issue.

scrap_iron · January 19, 2012, 4:54pm

I don’t have a boiler maker,I have converted keg. I use a direct fire system and circulate with a march pump.Without the pump I had to fire the MT for a couple of minutes and then stir real well, then check temp.It was easy to overshoot temps using this method and all that stirring sucks. Now I use a copper tube that fits inside the 1/2" silicone high temp tubing and tees out to the sides of the MT just under the surface of the mash. Using this setup I can maintain mash temps and ramp up temps for a step mash.

When I do this I leave the fire on the lowest setting and the valve on the pump open half way. If a step mash is used I turn the heat up just a little and keep an eye on the thermometers, one on outlet of MT and the main mash thermometer in the keg. Just to make sure the mash is not getting to hot. I circulate the whole time, it makes a very clear wort, but you could just do it enough to maintain temps if you like. I would change the fittings to 1/2" and on your lid , I just pump threw the copper tube coming down the side of the MT and it elbows over to the center just under the surface. Then I set my lid on top pushed over to the tube, no holes in lid.

brans041 · January 19, 2012, 5:04pm

[quote=“sethhobrin”]Re: Recirculating in Blichmann boilermaker MLT
I can probably insulate it fine so there is not much temp drop but I still need to be able to increase the heat to step mash or mash out without scorching the wort below the false bottom. that is the main issue.[/quote]

There is an online calculator to increase temp by adding a certain amount of water at a certain temp. Also you can fly sparge. If that doesn’t interest you, you may want to purchase a march pump, unless you want to be moving water around all the time.

sethhobrin · January 19, 2012, 5:48pm

I do fly sparge already normally. but I was under the impression i still needed to mash out(increase temp to 170 or so before fly sparging).

Are you saying that if i am fly sparging that raising temp for mashing out is not necessary?

scrap_iron · January 19, 2012, 6:16pm

A mashout is really not needed in either type of sparge unless you want to stop enzyme activity. If I don’t want the enzymes to continue working, making a more fermentable wort, I fire up the BK as I’m collecting wort and when it hits the hotter temps it denatures the enzymes.

Hope this helps, cheers, Mike .

mrv · January 20, 2012, 2:36am

[quote=“scrap iron”]I don’t have a boiler maker,I have converted keg. I use a direct fire system and circulate with a march pump.Without the pump I had to fire the MT for a couple of minutes and then stir real well, then check temp.It was easy to overshoot temps using this method and all that stirring sucks. Now I use a copper tube that fits inside the 1/2" silicone high temp tubing and tees out to the sides of the MT just under the surface of the mash. Using this setup I can maintain mash temps and ramp up temps for a step mash.

When I do this I leave the fire on the lowest setting and the valve on the pump open half way. If a step mash is used I turn the heat up just a little and keep an eye on the thermometers, one on outlet of MT and the main mash thermometer in the keg. Just to make sure the mash is not getting to hot. I circulate the whole time, it makes a very clear wort, but you could just do it enough to maintain temps if you like. I would change the fittings to 1/2" and on your lid , I just pump threw the copper tube coming down the side of the MT and it elbows over to the center just under the surface. Then I set my lid on top pushed over to the tube, no holes in lid.[/quote]

I have a keg also. Right now its manual recirculation, but a pump and insulation are in the future. I was fly sparging with a homemade false bottom, the last two brews I tried batch sparging with a braid. The container method works, it just involves more attention. Like scrap iron said, 1/2" fittings.