Metal mash tun continued

[RNBEERGUY]

Hey guys I have a 10 gallon bayou classic brew kettle that I plan on using as a mash tun I have two questions. One does it matter that the false bottom that came with it sits 3 inches off the bottom?

two I did a test with 120 degree water to the thermometer line and after 30 minutes temp only dropped 2 degrees i used direct flame to bring it back up? if it only drops that low do I really need a way to insulate it? if so please let me know any cheap way to insulate it.

 

[IslandLizard]

If you can't drain the wort from those 3 inches underneath the false bottom, that volume is considered "mash tun deadspace." That would be a real lot.
That trapped volume will impact your mash and efficiency in a negative way. If it can't be stirred it is pretty much isolated from the mash process.

Where is you spigot/bulkhead located? above or below the false bottom?

Is that volume there because the false bottom sits on top of a lip or a recessed area in the bottom?

It is hard to believe you only lost 2 degrees over 30' without any insulation, unless you were outside in 118° heat and no breeze.
You sure the water was mixed thoroughly when taking readings? Since we mash at considerably higher temps, between 146 and 160F your heat loss will certainly increase. Wrap a sleeping bag or thick moving blanket or some other insulation around it and cover the top of the lid with insulation too. Don't fire your burner before removing those flammable materials first, though.

 

[RNBEERGUY]

If you can't drain the wort from those 3 inches underneath the false bottom, that volume is considered "mash tun deadspace." That would be a real lot.
That trapped volume will impact your mash and efficiency in a negative way. If it can't be stirred it is pretty much isolated from the mash process.

Where is you spigot/bulkhead located? above or below the false bottom?

Is that volume there because the false bottom sits on top of a lip or a recessed area in the bottom?

It is hard to believe you only lost 2 degrees over 30' without any insulation, unless you were outside in 118° heat and no breeze.
You sure the water was mixed thoroughly when taking readings? Since we mash at considerably higher temps, between 146 and 160F your heat loss will certainly increase. Wrap a sleeping bag or thick moving blanket or some other insulation around it and cover the top of the lid with insulation too. Don't fire your burner before removing those flammable materials first, though.

Thanks for the reply btw i see your in pasadena md Im not too far from there.
to answer your first question the spigot is located below the false bottom that sits on top of a lip. I do have a mesh tube that attaches to the spigot can I use that instead of the false bottom?

As far as the insulation is there anything at lowes you reccommend will the blanket be enough?

 

[mongoose33]

Good comments from Lizard. About temp loss, I can believe he lost only 2 degrees in 30 minutes, but here's the catch: he won't mash at that temp. He'll be at 150, 154, something like that. The greater the difference between mash temp and ambient temp, the faster it will cool. So I'd expect over an hour for him to lose 5 or 6 degrees or even more. Whatever that kettle is sitting on will suck heat out of it, as well as the temp loss at the sides.

RNBeerGuy: yes, you want to insulate. Some people use sleeping bags, others old quilts, others moving blankets, whatever. I use a 12-gallon Igloo Cooler as a mash tun, wrap it with an old quilt, and even then, I'm losing a few degrees over the course of an hour. You'll lose more if you let a metal kettle sit uninsulated.

 

[Lefou]

Speaking as someone who mashes on a stovetop with a tri-clad kettle, I would say using a kettle that had a slightly higher bottom thickness would allow a brewer to apply a small amount of direct heat to help overcome slight heat losses during mashing. Don't forget to stir, though.
The extra amount of thermal mass can reduce the need for insulating materials and keep your temps very stable. My method uses a 7.5gal Anvil with a nice thermometer and fitted steel false bottom with very little dead space. In my opinion, it gives very reliable results with all grain mashes.