Partial mashing in an oven?

[leftcontact]

For the five years I’ve been brewing, I’ve used a small igloo cooler to do mini matches. Discovered the other day that the oven in this house we’ve moved to can be set as low as 105. Which means I can hit mash temps in an oven.

This leads to several questions, then.

1) Does it make sense to continue to mash in the igloo, or just mash in my boil kettle? Or a smaller pot? Basically, with the insulation that was keeping me at mash temps before now just get in the way?

2) can I “air mash”? Bake the grains at 155 or whatever and then just sparge? I’m thinking no, but would raising the grains to mash temp before I add strike water help efficiency/conversion?

3) if I do raise the grain temps pre-mash, any reason not to just set strike and sparge water temps to the mash temp (vs. a few degrees higher, expecting the thermal mass of the grain to drop the water temp?)

Thanks!

 

[xico]

I've considered this before myself. I would test it out with water, do you have a laser thermometer? I would place the mash tun with water in the oven but also add coffee mugs in different parts of the oven. When they heat up to temp, shoot each one to determine if you have any hot/cold spots in your over and how accurate the gauge is on your stove to calibrate accordingly.

If you do try it please share.

I would get the strike water to temp, have the oven going at your mash temp, add grains, stir and throw it in.

 

[Lefou]

I've heated mash water in my gas oven, monitoring the temperature with a thermometer. My experience showed the heat wouldn't stay constant, it would rise and drop in a range that wasn't acceptable for a stable mash.
This convinced me to step mash on the stovetop instead where I could control the rising temperature by hand.

 

[leftcontact]

I've considered this before myself. I would test it out with water, do you have a laser thermometer? I would place the mash tun with water in the oven but also add coffee mugs in different parts of the oven. When they heat up to temp, shoot each one to determine if you have any hot/cold spots in your over and how accurate the gauge is on your stove to calibrate accordingly.

If you do try it please share.

I would get the strike water to temp, have the oven going at your mash temp, add grains, stir and throw it in.

No laser thermometer but now I think i *neeeeed* one. Good idea.

 

[leftcontact]

I've heated mash water in my gas oven, monitoring the temperature with a thermometer. My experience showed the heat wouldn't stay constant, it would rise and drop in a range that wasn't acceptable for a stable mash.
This convinced me to step mash on the stovetop instead where I could control the rising temperature by hand.

Hmm, ok. Stove is what I’ve been using, but the bottom of the microwave is low enough to be annoying. Well, I’ll try it, see what happens. Thanks for the advice, though!

 

[RM-MN]

No laser thermometer but now I think i *neeeeed* one. Good idea.

Yes, you really do need one. The good news is that they are cheap. There's a selection on Ebay that will do what you need. I use mine to monitor fermentation temperature. I no longer have to kneel down and squint at the stick on thermometer, I can stand across the room and just "shoot" the infrared thermometer at it, using the included laser to see where I am shooting.

http://www.ebay.com/bhp/infrared-thermometer

Don't worry overmuch about the fluctuation of temp in your oven. Heat it to 150 plus or minus a few degrees and turn it off. Put the boil kettle with the grains to be mashed in there and close the door. The thermal mass of the mash will not lose heat quickly and the warm oven will help it more yet. Most of the conversion will be done long before the temperature drops significantly.

 

[wilserbrewer]

I think RM-MN is saying is once your mash is at proper temp to put it in the oven. Just clearing up as this thread previously discussed heating the mash in the oven, not a good idea IMO.

Warm oven works well to maintain a steady mash temp, not so much to achieve one would be my guess.

 

[Sadu]

Agree with Wilder and rm-mn above. Set your oven to mash temps, heat the strike water on the stovetop and add grain. Put the pot in the oven. The oven does a superb job of holding temps but the stovetop is better for heating the water initially.

 

[leftcontact]

Agree with Wilder and rm-mn above. Set your oven to mash temps, heat the strike water on the stovetop and add grain. Put the pot in the oven. The oven does a superb job of holding temps but the stovetop is better for heating the water initially.

Ok, that all makes a lot of sense. Thanks!

 

[xico]

I would get the strike water to temp, have the oven going at your mash temp, add grains, stir and throw it in.

In case I wasn't clear in my post I agree with others that you use the oven as temp management not ramp up.

 

[Mothman]

Just to add my support to this idea, I mash in the oven and it works well for me.

I do smaller (3.5 gallon) batches, in an 8 gallon pot and it fits fine in the oven.

I heat the oven to it's lowest setting (170* in my case) then as I'm approaching my strike temperature in the kettle (on stove-top) I turn the oven off.

I reach strike temp, mash in, stir well, put the pot in the oven, with the lid on, and I use a wired probe temperature monitor, hanging in the kettle, probe in the mash, wire out the door (thin wire, so no issue closing the oven door) to the display on the counter.

Easy to monitor temps (not totally accurate, as it's only measuring near the top of the mash, but good enough for me), and I seem to lose a couple degrees over the course of an hour.

If I lose a little too much (happened a couple times for some reason), and want to raise it back up a tad, I just turned the oven on for a few minutes and then off again, and that seems to raise the mash temp a couple degrees.