Mashing in the oven instead of a tun

Much of what I have read about all grain mashing is that it is done using a converted cooler as a mash tun. Would just placing the mash in an oven at 150 degrees be as good or a better solution? Seems like you could hold a steady temp more effectively this way.

That's the old school way.

From the googles. (hint hint)
http://www.howtobrew.com/section3/chapter16-1.html
http://byo.com/mrwizard/777.html
http://www.bodensatz.com/staticpages/index.php?page=first-mash
http://www.humpsbrewing.bluegosling.com/2008/06/08/all-grain-1/
(with the cool picture)



And from our own search

https://www.homebrewtalk.com/archive/index.php/t-59598.html

I believe it's also mentioned in Papazian

My oven thermostadt only goes down to 170F, otherwise it's reasonable. The truth is, a cooler mash/lauter tun has even more utility because it hold temp really well and you're not using any energy over that length of time. I suppose you could install a separation medium in a oven based mash tun but I would think most people transfer to a standalone lauter tun for sparging. Too much work for me.

The range and accuracy of the ovens thermostat is an issue, but the real reason I never tried it is because Ive never had an oven big enough to fit a 48qt stock pot.

It seems it would be easier to use an oven mash for a 5 gallon batch. As long as you test the accuracy of the oven's thermostat.

Can't imagine it cranks your energy bill up that much unless it's your day job. Which as that point why would you use the oven?

Holy thread bumping, batman.

I remember reading an article on this and checking my oven and it doesn't go below 300f....

Also most ovens fluctuate greatly. If your oven is set to 148 it's probably not going to stay there consistently. It's going to like drop into the 130s then over heat to the 150s.

just did a partial mash using this technique for the first time - 3.5 pounds of grain in 1 1/2 gallons water heated to 165 (154 deg after adding / mixing grain). heated oven to 170 and when I put the kettle in (actually 2 - 5 gallon SS pots) turned off the heat. 60 minutes later the temp was 153.5. used paint strainer bag and sparged each with 1 1/2 gal water at 170 deg

I just tried this with a full mash (feel the burn in those biceps, baby). I got the mash (11# grain) up to 155 on the stovetop and pre-heated the oven to 170f (lowest possible). Turned off the oven and put the mash tun w/ lid into the oven. Used the dial thermo on the front of it to track the temp. It was 155F for the first 30 minutes, then dropped to 154F after 45 minutes. After 60 min, it was down to 152F. I guess I could have bumped the oven back on at 30 min to keep things more constant.

Funny thing, I just started using the old pipe-bomb style RIMS which does a great job holding the exact temperature in the heating chamber, but isn't easily controlled in the tun where you want it to be precise. I've tried constantly stirring the mash with the old ice-cream machine turned brew tool as well as adding supplemental heat underneath the tun. Nothing seemed to hold the temp as steady as simply wrapping the tun with an old sleeping bag, but I'm not a big fan of putting anything flammable on the stovetop even when I'm 100% sure everything is turned off.

Anyway, this oven mashing will be my go to method until I graduate above 5 gllon batches. I don't see that happening anytime soon since I can't seem to drink what I already have brewed fast enough (got a Bock, Stout, Blonde and IPA in the fridge and a tripel IPA waiting in the "cellar"). PROST!

I'm gonna use the techniques in the 2 posts above for my first partial mash (heat to 170, then turn off). Mainly because I can mash in my small 12 qt pot and fit it in the oven, then batch/dunk sparge in my big 'ol kettle, add the mash water (I'm sure there is a more technical term for this wort ) and go. No purchase of a cooler or need to wrap my pot in a sleeping bag. Just seems easy for a 45 min PM.

Homebrewtastic said:

Also most ovens fluctuate greatly. If your oven is set to 148 it's probably not going to stay there consistently. It's going to like drop into the 130s then over heat to the 150s.

Click to expand...

I'm thread bumping, but I'm sure other newbie's will come across this like I did so I thought I would provide some useful info on this matter.

Now.....regarding mashing in the oven.
Thermodynamics 101

Q=UAdeltaT

Q would be the amount of heat transfered either into or out of your mash.

U is the heat transfer coeff. of air, which air is really really bad transfering heat (this is good for us)

A is the area, or the surface area of your pot. I'm guessing most pots are made with a minimal amount of material respective to their volume because they could sell them cheaper. This makes A as low as practical.

deltaT is the difference in your mash temp and the difference in the oven temp which we intentionally keep as low as possible.

U is always going to be small with air, A is as small as practical, and so is delta T. small number * small number * small number = really small number
Have you ever set a mash pot outside, even when it's really cold, and it still takes forever to cool? That's because air is so poor at transfering heat. Even if your oven is 10 or 20 degrees off from your mash temp, it will take quite a long time for your mash to change even 1 degree.

2-3 degrees/hour on my particular setup. Since my first, I have tweaked my process. I pull the mash out at 20 min to stir. When I pull it out, I turn the oven back on at 170 just to keep it a little warmer. Repeat at 40 min. At 60min, my temp is usually the same as when I put it in the oven.

Stirring the mash cools it pretty effectively, so if I do that I can bring it right to my target temp before going in the oven. Stirring during the mash helps bring up your efficiency (IME and from what I have read). I just have to be careful not to "over stir" while mashing.

As a small batch brewer, this sounds like a great idea. My oven goes to 170 as well. I think I will use this for my next brew.

Do you realize that this thread has cobwebs all over it?

I mash in my 10 gallon brew pot ($30 at webrestaurant.com, I think the lid was an extra $15) I put a bath towel underneath and wrap it in a quilt, keeps the temp within a couple of degrees of what I want for the entire 60ish minutes.
Edit, haha didn't know this thread was so old.
Small batches I do in an igloo 2 gallon drink cooler I bought at walmart.