Direct fire MT with Sanke - Questions!!!

So I plan to use a sanke keg for a MT that I can direct fire. I will be recirculating the wort during heating of course.

1) I plan on a false bottom too. How low can I put the false bottom so that I can still direct fire without worrying about scorching? I will have a diptube too, so no worry about dead space. But I don't want too much height to either, obviously.

I understand there's 1 gallon of liquid in the dimple of sankes. Can I have the false bottom just a tab above that or do I need more room for no scorching?

2) Also when recirculating to people just lay the hose over the opening and let it flow? I was thinking of adding a thermometer inline to the return line of the recirc tubbing so I know to not exceed 168 for the wort going back into the MT. Or is this a waste of time?

3) If I want to do step mashing, would I be able to heat the mash 20 degree or so in a reasonable amount of time without scorching wort or would this be very slow? I guess the same with raising to mashout from 150ish to 168. Will this be quick without scorching?

4) Lastly, what propane burner would you recommend that can go low enough without scorching, but still able to heat 6-7 gallons of strike water in decent time.

Thanks all.

Gregg

no need for an in line therm - as long as you have a therm in the MLT you're fine. I use an SQ 14 burner. They are very adjustable an I have not scorched the wort yet.

1. yes

2. good idea to have a thermo, how else are you going to know the temp if you are direct firing, unless you are PID or some other form of burner control. You want to know that you are not heating the mash beyond whatever threshold you set. Knowing the MLT temps won't help until it is too late. The closer to the outlet from the bottom of the keggle that you can put a thermo the better off you are. If you are heating the mash wort to 195F it won't instantly register throughout the rest of the mash for some time.

3. Never tried that direct fire. I do a RIMS recirc and it takes awhile with this system to go up 20 degrees. I don't step mash, only use the ramping up for mash out.

4. Hurricane burner is a nice option using low pressure propane and it can be converted easily to NG if you need to.

thanks all

ghart999 said:

So I plan to use a sanke keg for a MT that I can direct fire. I will be recirculating the wort during heating of course.

1) I plan on a false bottom too. How low can I put the false bottom so that I can still direct fire without worrying about scorching? I will have a diptube too, so no worry about dead space. But I don't want too much height to either, obviously.

I understand there's 1 gallon of liquid in the dimple of sankes. Can I have the false bottom just a tab above that or do I need more room for no scorching?

Click to expand...

I have a full, hinged FB that sits on the bottom weld. Sure, it's got some dead space underneath the grain bed, but I actually think that's ideal for direct-fired MLTs, since you'll just be heating the wort and not the grain.

I used to have a smaller 10" FB that I kept tight against the bottom with a hose clamp on the pickup tube. Since it had limited surface area, I had problems with the grain bed compacting and sticking during recirculation. I've had better results with the full FB, but it can still stick if you recirculate with the pump at full flow.

Here's a view inside the MLT.

ghart999 said:

2) Also when recirculating to people just lay the hose over the opening and let it flow? I was thinking of adding a thermometer inline to the return line of the recirc tubbing so I know to not exceed 168 for the wort going back into the MT. Or is this a waste of time?

Click to expand...

You can see in the pic above that I have a return tube mounted on the top of the MLT, as much so I can hook up the quick-disconnect to the outside as anything else. It essentially works exactly like a hose laying on top of the grain.

Now, as far as the thermo goes, I think having a way to measure the temp of the heated wort exiting the MLT is highly valuable. You don't want the wort to be super-heated (much above your target step) so that you ensure you aren't denaturing the enzymes. When you're doing a mash-out it's not as critical as when you're doing a protein->sacc step. I've got one mounted at the pump, but anywhere inline would work. I've also got a thermo probe mounted with the sight glass to monitor the mash temps, too.

ghart999 said:

3) If I want to do step mashing, would I be able to heat the mash 20 degree or so in a reasonable amount of time without scorching wort or would this be very slow? I guess the same with raising to mashout from 150ish to 168. Will this be quick without scorching?

Click to expand...

I've found you can get ~ 2' per minute without overheating the wort (see above). You can easily heat the wort faster, but I think it's a bad idea. As long as the grain bed doesn't stick and the pump continues giving you good flow, you won't scorch the wort/grain.

ghart999 said:

4) Lastly, what propane burner would you recommend that can go low enough without scorching, but still able to heat 6-7 gallons of strike water in decent time.

Click to expand...

I think people over-think this all the time. Any propane burner will work just fine. I've used several with good results. The last stand I built has 3 of the cheap $8 burners and I don't have any complaints.

Good luck. Keep us updated on your build.

Thanks a lot for the pics and help. I think I will do something like this. Your return at the top of the MT, do you worry about the wort dropping straight down into one place. Do you think sprinkling is needed or anything?

It actually swirls around on top of the grain bed. The grain bed is so deep, esp w/ 10 gal batches, that there's no need to "sprinkle" the return.

Makes sense. Thanks a lot.

ghart999 said:

So I plan to use a sanke keg for a MT that I can direct fire. I will be recirculating the wort during heating of course.

1) I plan on a false bottom too. How low can I put the false bottom so that I can still direct fire without worrying about scorching? I will have a diptube too, so no worry about dead space. But I don't want too much height to either, obviously.

Click to expand...

You want the heat pattern of burner to be within the circle that the FB covers. In other words, the heat should hit wort, not thick mash. My full FB has 7/8ths of a gallon of "idle space". I don't call it deadspace because that's the measure of liquid left in the tun when you fully drain.

2) Also when recirculating to people just lay the hose over the opening and let it flow? I was thinking of adding a thermometer inline to the return line of the recirc tubbing so I know to not exceed 168 for the wort going back into the MT. Or is this a waste of time?

Click to expand...

This is a reasonable idea. I often find myself holding the small handheld probe in the outlet stream to check for overheating but the inline idea is better. Even if it's a cheap $7 digital, it's better than nothing.

3) If I want to do step mashing, would I be able to heat the mash 20 degree or so in a reasonable amount of time without scorching wort or would this be very slow? I guess the same with raising to mashout from 150ish to 168. Will this be quick without scorching?

Click to expand...

I typically get 150-168 in about 12 minutes.

4) Lastly, what propane burner would you recommend that can go low enough without scorching, but still able to heat 6-7 gallons of strike water in decent time.

Click to expand...

I don't have the Hurricane burners yet but I predict liking them more than the 23-tip jets. If you really like the idea of the jet burners, get the 10 tip, not 23.

Thanks Bobby. Hurricane burners can do propane of NG right, depending on the right adapter. Also can the Hurricane's both heat strike water for 10 gallon batches at a decent speed as well as go low enough to heat my mashtun without issue?

Also am I correct that the Hurricane and Banjo are the same burners with different names?

Bobby_M said:

You want the heat pattern of burner to be within the circle that the FB covers. In other words, the heat should hit wort, not thick mash. My full FB has 7/8ths of a gallon of "idle space". I don't call it deadspace because that's the measure of liquid left in the tun when you fully drain.




This is a reasonable idea. I often find myself holding the small handheld probe in the outlet stream to check for overheating but the inline idea is better. Even if it's a cheap $7 digital, it's better than nothing.



I typically get 150-168 in about 12 minutes.




I don't have the Hurricane burners yet but I predict liking them more than the 23-tip jets. If you really like the idea of the jet burners, get the 10 tip, not 23.

Click to expand...

ghart999 said:

Thanks a lot for the pics and help. I think I will do something like this. Your return at the top of the MT, do you worry about the wort dropping straight down into one place. Do you think sprinkling is needed or anything?

Click to expand...

I just did a 10 gallon batch of Holiday Chocolate Stout the other day. We dragged the mash tun into the house to keep it at a decent ambient temp since the garage was about 22 degrees. We had tried to wrap it in an old sleeping bag...bad idea (it was vinyl...oops). After about 45 min the mash had dropped from 155 to 144, so I decided to heat it up. We just threw it back on the burner at low and I just slowly stirred the mash. I have a full size false bottom from Climax. It seemed to work quite well considering it was a stone age method. I probably should get a pump, but my kegerator and pump fund just went out the window - had to get a new washer.