New mash tun prob

[poopypants]

Just made a ten gallon square mash tun with manifold. Tested it with just water and it drops temp 3degrees every half hour. And that was with a blanket wrapped around it. This will be my first all grain and don't want to screw it up. Any suggestions?

 

[daksin]

Did you preheat it with some boiling water first? That's a common practice.

 

[runningweird]

I wouldn't use boiling water in your plastic mash tun, try adding hot water from your tap - boiling water will stress the plastic(or warp it immediately) and over time will cause damage.

another point is that your mash(grain + water) will lose less heat per time than just water will. my round cooler lost only about 1-2 degrees per hour without any extra insulation(even on cold winter days)


To preheat your tun: fill with water as hot as you can get from your tap, put on the lid. that's it. when you do your mash in temp calculations take the temperature of your water in the tun and use that in addition the temperature of your grain.


when you are ready to start your mash dump the water or save it in buckets (use it to sparge perhaps?) then go about mashing in normally - either grain or water first. I prefer water first so I can avoid dough balls.

good luck!

 

[fair78]

Good advice above. Generally my strike water needs to be around 166. So i will heat the strike water to about 170ish, dump it in my mash tun, close the lid and wait a minute or two and the temp is at 166 and the tun is preheated. Same idea, less steps.

 

[kylevester]

I'll support the above two posts. Without grains you'll lose temp faster. Most coolers will lose 1-3 degrees an hour with grains, and that's only in the spot you're measuring. fair78 gives a great way to pre-heat your cooler and hit your strike temp, just heat up about 5 degrees higher than the strike temp you need, wait til it's down to temp and add your grains.

Once grain is added, you'll also see bigger discrepancies across the bed on temps. At the walls, you'll lose more temp, but in the center you're likely to see next to no temp drop.