[bassface74]

I've got the money to purchase a decent gravity system with three 60 quart stainless kettles and a pump.  My question is, how do you control the mash tun heat without a cooler?  Can you have a flame under the mash?  I know, I have much to learn, but I have been brewing with a cooler set up for about a year and couldn't really find info on how it all works with an all kettle or keggle system.  Thanks for the schooling:)

[Hokerer]

Yeah, with a three kettle type of system, your mash tun is usually what it known as "direct fired".  That is, yes, it's got a burner under it too.

[bluesman]

For a direct fired mash tun you will need a false bottom and preferably a means to recirculate the wort. This will require a pump, thermowells and some hoses. I am in the final stages of building a single tier "Brutus 10" clone brewstand.

Here's a link to Lonnie Mac's site.

http://www.alenuts.com/Alenuts/brutus.html

My brewstand looks almost identical to Lonnie's. This is what is referred to as a direct-fired recirculating system.

[Kirk]

You can direct heat the MLT if the mash is thin and you stir.  Otherwise, the heat will create magma pockets and uneven heating, and killed enzymes.
I have one, and when I do single infusion, I use a program to calculate the strike water temp prior to dumping the grain in.  You probably have one of those.  The stainless steel holds temperature pretty good, as long as the grain is in there.  But if you remove the grain, like for decoctions, the temperature goes down, especially in cold weather.  But the good news is, with most of the grain removed, you have a very thin mash, and you can direct heat to raise the temp back to where it was, or even to a higher level if you want.

[Kirk]

+1 on the false bottom.  I have one.  Yours came with one?

[gordonstrong]

Not sure what you're asking.  How to get the mash to the correct temperature, or how to adjust it once you've mashed in?

If you are mashing in, then heat the water without the grain.  Then combine them.  That's mashing in.  You have to learn how much over in temperature you have to go to hit the mash temp you want on your system.  On mine, it's about 15F.

If you have a 3 vessel system, you can have boiling water in the HLT.  If you're under in temp, you can add boiling water to the mash tun.  If you're over in temp, you can add some chilled or room temp water.  If you don't want to mess with your mash thickness, then you can gently add heat and recirculate.  You need a false bottom and a pump to do this.  You can control the heat manually by taking temperature readings, or automatically with additional gear.  This works better with a thinner mash.  Temperatures can vary wildly within a mash tun, so stirring is important to even out the temperature.

Eventually you'll learn how your system responds and be able to hit your temperatures accurately.  You can use software, but it often wants to know a lot of variables that you won't necessarily know (like the thermal mass of your mash tun).

[tschmidlin]

In addition to what Gordon mentions, once you mash in and your temp is stabilized, you can cover it and wrap an insulated blanket around the mash tun to help it hold the temperature.  I made mine out of a hot water heater wrap and some aluminum tape.  Just a word of advice - if you decide you want to add some heat to the mash, remove the blanket first or it smells when it burns.

And the online strike water temperature calculators work well for me.  For my direct fired mash tun I don't worry about the thermal mass of the mash tun because it is already close enough to your mash temp that it won't throw things off too much.  I get a larger effect from the ambient temp in my garage (which determines my grain temp).

Really all you can do is start doing it and figure out what works for you.  It shouldn't take you many batches to dial it in.

[glastctbrew]

You can direct heat the MLT if the mash is thin and you stir.  Otherwise, the heat will create magma pockets and uneven heating, and killed enzymes.
I have one, and when I do single infusion, I use a program to calculate the strike water temp prior to dumping the grain in.  You probably have one of those.  The stainless steel holds temperature pretty good, as long as the grain is in there.  But if you remove the grain, like for decoctions, the temperature goes down, especially in cold weather.  But the good news is, with most of the grain removed, you have a very thin mash, and you can direct heat to raise the temp back to where it was, or even to a higher level if you want.

I've been planning out a direct fired system and I'm currently trying to decide whether to go with manual or automatic control.  Regardless of that point, how thin a mash are you talking about?  1.5qts/lb?  2qts/lb?

Tom, How often do you need to fire the mash tun when the ambient temps are in the low 40s or 30s, assuming you brew in such conditions, with your insulated blanket?

Ron, what temp switch/controller did you go with?

Thanks for the input and thanks for the timely thread JT.

[gordonstrong]

I tend to go closer to 2 qts/lb than 1.5, but most of the time I don't measure.  I'm just mashing to a certain consistency.  It makes less of a difference than you probably think.  Germans mash thin and they seem to make good beer.  But they want to pump the mash around too.

I have an insulated "mash cozy" too.  Made it more than a decade ago.  I lose maybe 1 degree an hour with it on vs. 8-10 degrees an hour with it off.  And that's in cold (but not freezing) weather.

When I add heat, I'm doing it manually.  Low heat underneath, pump on, pulling liquid from under the false bottom and putting it back on the top of the mash.  Taking temperature reading with probe in the mash.  So I'm always removing the warmest portion.  I use this approach more for step mashing and mashing out than I do for casual temperature adjustment, although it works for that too.  Automated systems do something similar, except they sense the temperature of what's being recirculated and adjust the heating accordingly.

[bluesman]

Ron, what temp switch/controller did you go with?

I use Love controllers. Love On/Off Temperature Controllers EW-93520-00
Economical temperature controller, 110 VAC, °F


http://www.coleparmer.com/catalog/product_view.asp?sku=9352000

[tschmidlin]

Tom, How often do you need to fire the mash tun when the ambient temps are in the low 40s or 30s, assuming you brew in such conditions, with your insulated blanket?

I typically don't worry about it, an extra degree over the course of the hour doesn't affect it enough for me to worry about.

When I add heat, I'm doing it manually.  Low heat underneath, pump on, pulling liquid from under the false bottom and putting it back on the top of the mash.  Taking temperature reading with probe in the mash.  So I'm always removing the warmest portion.  I use this approach more for step mashing and mashing out than I do for casual temperature adjustment, although it works for that too.  Automated systems do something similar, except they sense the temperature of what's being recirculated and adjust the heating accordingly.

You call that manual?  I do the same thing, but instead of a pump I am running it off into a pot and dumping it back on top.  That's manual.

[bassface74]

Thanks for all the replies!!  I was wondering how to hold the temps for a single infusion and figured I could make a "blanket" to cover the MLT.  My main concern was if I try to do a decoction type mash.  I wasn't sure if you could apply heat dirctly to the MLT to increase the temps, use pumps to re-cirrculate and heat, or if I had to pull wort out boil it and return to the MLT.  I didn't plan on using any pumps and since this is a gravity system it would be hard to do a decoction mash I guess.  I might have to invest in a pump to get the most out of a decoction mash right?

[glastctbrew]

Thanks for all the replies!!  I was wondering how to hold the temps for a single infusion and figured I could make a "blanket" to cover the MLT.  My main concern was if I try to do a decoction type mash.  I wasn't sure if you could apply heat dirctly to the MLT to increase the temps, use pumps to re-cirrculate and heat, or if I had to pull wort out boil it and return to the MLT.  I didn't plan on using any pumps and since this is a gravity system it would be hard to do a decoction mash I guess.  I might have to invest in a pump to get the most out of a decoction mash right?

Well, if you are doing a decoction you would be pulling a thick portion of the mash out to boil regardless of what you're mashing in.  This setup makes step mashing/mash out much easier, with practice I'm sure, by allowing to hit your step/mash out temp through direct heating and without having to further thin your mash.  Down side is the potential to scorch the mash or over shoot the desired temp.

This is the link to Kai's write up on decoction mashing.  It's a great resource.
http://braukaiser.com/wiki/index.php/Decoction_Mashing

Thanks for the info Ron, Tom and Gordon!

edited to add link to Kai's write up and a thank you.

[Kirk]

 

Thanks for all the replies!!  I was wondering how to hold the temps for a single infusion and figured I could make a "blanket" to cover the MLT.  My main concern was if I try to do a decoction type mash.  I wasn't sure if you could apply heat dirctly to the MLT to increase the temps, use pumps to re-cirrculate and heat, or if I had to pull wort out boil it and return to the MLT.  I didn't plan on using any pumps and since this is a gravity system it would be hard to do a decoction mash I guess.  I might have to invest in a pump to get the most out of a decoction mash right?

Not IMO.  With the decoction pulled you have a very thin mash, so with low heat and stirring you can raise the heat in your MLT back to where you want it.  I add HLT water to the decoction to prevent scorching.  My mash keeps getting thinner as I go along the process, so that by the time I'm direct heating the whole enchilada, grain and all, that last step to mashout, I'm at about 2 or 2 1/2 qts. per pound.

[bassface74]

I was wondering about the mash being too thin if I just added HLT water.  Right now, I do a ratio of about 1.25quarts to a pound of grain.  Bumping the water amount up from the HLT to hit target temps might do the trick, I'll give it a shot on some batches to see how it goes.  That seems to simplest thing for me to do, if it doesn't work I'll stoke up the fire and stir!!!  haha!!