Recirculated temperature mash

[AKnewbrews]

I just bought a decent amount of equipment to further my AG process. I only have one under my belt, and I am remedying the problem points. I am doing a temperature mash using direct heat instead of insulation (i.e igloo cooler) to keep the temp target. Surprisingly, my Kettle/MLT actually holds a decent amount of heat in, and only next to the most lowest setting on the burner keeps the temp stable.

So my last batch, I had a problem with scorching on the bottom of the MLT during mashing due to the direct heat. Obviously the scorching was a little hot for mashing. I have purchased a pump to recirculate the wort from bottom to top, keeping the temperature more even during the mash schedule. What do you think about this? Any thoughts?

I also invested in some nice SS Cam-lock QD's, some silicone hose, and a plate chiller to get things going a little faster. I plan on getting three brews done within a day or three for my upcoming wedding July 30. So the investment in the equipment is a great excuse!...right?

Now I have a Kettle/MLT, plate chiller, water filter, and pump all Cam-locked for quick and easy service. Made up 2 6 foot hoses with female cams on each end and an 8 footer with a female cam on one end and a male on the other for transfers that don't require a QD connection or as an extension to the other 2 hoses for whatever reason.

Yay fun!

Wedding brews: A session stout, a wheat, and an American pale ale

 

[ehedge20]

Well sir you are on your way to a nice rig! I use the direct fire method as well and you do need to recirculate to keep from scorching the wort. The flow does not have to be at the maximum the pump can push either as I run it with the valve half shut. Also you will want to disperse the return wart against the side of the MLT so you do not create channeling in the grain bed. 10 min before I the mash is done give it a stir, and shut off the flame and the pump so that everything has a chance to settle before sparging.

 

[AKnewbrews]

Well after last weekend of brewing 3 beers, one a day, I have more or less dialed in my brewing with temperature mash. I have found that my "deadspace" under my false bottom, if you can call it that, is very sensitive to recirculation with the pump from bottom to top. I have to keep my valve no more than 1/3 open with the pump running during mashing to prevent a vacuum from ocurring under the false bottom. If that happens, I lose pumping power and the hydraulic needed to recirculate. I have however, been able to keep a very consistent temperature during mashing varying only +/- 1 degree by leaving the pump run the entire mash schedule at 1/3 flow and with extremely small adjustments in heat application.

I think with this setup, a I can get consistency with brewing. I have hit the target OG everytime.

Also, since I constantly recirculate, I have no need to vorlauf and my grain bed is already set. I feel there is no need to stir the grain (or is there?). If I stir the grain bed, this disrupts my flow under the false bottom and I can lose my hyraulic pumping power.

So far 75 to 80% efficiency is what I have been getting and my fly sparging has been doing a great job. I would try batch sparging, but I feel like fly sparging is easier since my grain bed is already set and ready to filter the water and extract sugars.

 

[Catt22]

I feel there is no need to stir the grain (or is there?). If I stir the grain bed, this disrupts my flow under the false bottom and I can lose my hyraulic pumping power.

IMO, stirring frequently and thoroughly is a must; at least on my system it is. Stirring should not cause you to lose "hydraulic pumping power" which I assume is the same as losing prime. I'm in the pro-stirring camp all the way.

 

[AKnewbrews]

I will have to experiment more and maybe try stirring again. I think part of the problem is that with the mash in the tun, it is thicker, hence the reason for the 1/3 flow to keep it from losing prime. Therefore, the 1/3 flow makes it harder to get the prime back.

What exactly does stirring do during the mash? The obvious of preventing scorching, I have remedied. I have also remedied heat distribution through the recirculation process as well. Stirring would help with even heat distribution. I do stir the mash for the first couple minutes, but after that, I allow it to settle for the rest of the mash and recirculate.

Does it perform the similar function as sparging would by allowing more contact of the sugars with the water? Does it help conversion, or is most of the conversion process based on chemistry such as pH, temperature and other chemical processes?

 

[bannonb]

You need a false bottom to keep only wort in the bottom of the mash tun to allow recirc to flow more freely. I use a Sankey keg and use the Sabco false bottom. You can still have too much pumping power and compact your grain bed and get a stuck sparge if not careful, but you should never cavitate if there's enough wort to recirc.


I used to do recirc only with gas heat to adjust temperature. Last year I added a RIMS tube and temp controller to the equation.

Now my wort moves through the grain bed out to to the temp controller, heating element makes up difference, then recircs into mash again. Temps are constant, now one less variable to consider in your beer quality...

I stir during mash-in, maybe half way through, then when sparging...just to be sure everything is lifted and separated.

 

[AKnewbrews]

I have a false bottom. It works great. It is the Blichmann false bottom adapted to a 32 qt pot. It is sealed to the sides of the pot, so wort/sparge flows only through the grain bed and through the false bottom. The issue I have with low flow is that the false bottom sits about 5/16" to 1/4" from the bottom of the pot. It is great in regards to leaving NOTHING behind after the sparge is completed (my dip tube is about 3/16" to 1/8" from the bottom of the pot). So I have less leeway for my "deadspace" to go empty and lose prime due to smaller "deadspace" capacity.