Holding temp for partial mash

Hi all,

I’m thinking about trying my first partial mash soon. I’ve read over the process and it all makes sense to me, but I’m a little concerned about maintaining the mash temperature for so long.

I’ve read that some people remove the kettle from the flame, put the lid on it and wrap it in a blanket or towel. Does that really work for holding the temp for upwards of an hour? Are there other methods you can recommend?

Also, how do you monitor the temp of your mash without letting out heat? I imagine I’d have to remove the lid to use the thermometer accurately.

Thanks in advance for the help

What are going to use for a MT? If you are using a kettle bring the water a little above your striking temps and dough in. If you are using a bucket or cooler it is a good idea to add the strike water a lot warmer so you pre-heat the MT.
I use a direct fired kettle and then cover with a blanket. It will maintain my temps for 90 mins with a loss of 2* which is plenty accurate for me.
When you hit the temp you want put the lid on and cover with a blanket. You don’t need to continue to monitor the temps.

In the most recent Beersmith podcast the guest speaker said the first 10 minutes were the most critical for enzymatic activity. The rest of the time was to solubize the sugars enough for us to extract them.

Okay, that clears it up for me. Thanks guys. I thought you were supposed to monitor temps during the entire mash somehow without drawing out the heat. I’m using my kettle for the MT so I’ll get it a little above the strike temp before dropping in the grain. I think the blanket method sounds like it’ll work for me. And that’s interesting about the first 10 minutes being most critical. Good to know.

When did partial mash I used a smaller kettle that could fit in my oven. Once I got the mash to the correct temperature I just threw it in the oven on ‘warm’ (160 degrees). That or heat the oven to as low as it goes for a while and then turn it it off when you throw the kettle in there to hold the mash temp. I’d dump the wort I got from my mini-mash into my larger boil kettle.

The nice thing about a direct fired kettle is that you are heating the entire MT while you heat your strike water which will help with the temp drop you get when adding the grains (place them at room temp the night before brewing) and overall heat loss as you now have more thermal mass.

I used an old insulated coat on the kettle. I would check temp, and if needed remove coat and fire it up after 30 minutes, then remove flame and wrap again.

This is basically what I do for partial mash. My oven has digital temp setting and the lowest it goes is 170*. When I put my 5 gallon kettle in there after mashing in, I turn the oven off. Last time the mash held a steady 152* for the whole hour. Really easy and I boil in the same vessel so nothing else to clean except the bag.

[quote=“Mabus”]

This is basically what I do for partial mash. My oven has digital temp setting and the lowest it goes is 170*. When I put my 5 gallon kettle in there after mashing in, I turn the oven off. Last time the mash held a steady 152* for the whole hour. Really easy and I boil in the same vessel so nothing else to clean except the bag.[/quote]

My oven only goes down to 170* as well so I didn’t consider using it to hold the mash temp, but this sounds like a great idea. Think I’ll try this next time. I just did my first partial mash and used the ol’ wrap in a blanket method. I secured the blanket to the kettle using bungee cords too. It worked fine, but I think the oven just sounds easier. Thanks