Insulating kettle bottom

[brewprint]

I had heard over the weekend that when doing electric brewing that the bottom of the kettle needs to be insulated as well.

I have a 20 gallon kettle that I'll be doing BIAB with. I figured I would use reflectix around the outside but not sure about the bottom. It'll be on a stainless steel table.

This is a 5500 watt system.

 

[mkirkland]

I insulate the bottle of my Keggles of for the reason of heat retention.

 

[nettekdl]

You could cut a donut of Styrofoam insulation from any hardware store and just set it on that, or tape it to the reflectix

 

[BrunDog]

If you brew in cold temps (not too common with electric unless you are in a cold garage), and if you insulate the sides for temp stability, it would make sense to insulate the bottom as well. But if on a heat sink like a stainless table, you definitely want to insulate the bottom independent of ambient environment.

 

[brewprint]

I will be brewing in a cold garage on a stainless table.

You're thinking just foam? I'm not sure reflectix would be adequate for a 20 gallon kettle.

 

[BrunDog]

Something solid so your kettle doesn't wobble. Remember a full kettle is heavy and will compress even firm foams. Even wood would be ok. Some people use silicone or cork mats.

 

[iijakii]

I'm pretty fancy and have a blanket under mine.

 

[FuzzeWuzze]

If you brew in cold temps (not too common with electric unless you are in a cold garage), and if you insulate the sides for temp stability, it would make sense to insulate the bottom as well. But if on a heat sink like a stainless table, you definitely want to insulate the bottom independent of ambient environment.

I thought this would be a bigger deal than it was for me. Brewing in 40f in a stainless table I get my 19 gallons of hlt water to temp at the rate the calculations say I should more or less within a minute of what they say. And I'm using strangebrew so I have a data log that shows it.

Wasn't worth all the effort to save 2 minutes on a hlt heat up that already takes 50 minutes.

 

[BrunDog]

It's not just about time. It's about heat bleeding off. You don't want to have temperature variances in your mash. If you pull lots of heat out through the sides and bottom, that heat comes from the local mash mix. Which means you will need to put hotter liquid back in, creating large temp differences throughout the mash volume.

 

[FuzzeWuzze]

It's not just about time. It's about heat bleeding off. You don't want to have temperature variances in your mash. If you pull lots of heat out through the sides and bottom, that heat comes from the local mash mix. Which means you will need to put hotter liquid back in, creating large temp differences throughout the mash volume.

I guess maybe it matters for some setups then more than others, i usually recirc at or near full speed with my 809HS pump and am usually setting my HLT to 2F above my target temp and hold that.

 

[BrunDog]

The only way to really know is out a fast, accurate thermometer (like a Thermapen) and pure it in different places through the mash.

 

[TexasWine]

I had heard over the weekend that when doing electric brewing that the bottom of the kettle needs to be insulated as well.

I have a 20 gallon kettle that I'll be doing BIAB with. I figured I would use reflectix around the outside but not sure about the bottom. It'll be on a stainless steel table.

This is a 5500 watt system.

I use a 2x8 piece of wood. Doesn't completely cover the bottom, but heat loss due to natural convection from the little bit of exposed kettle is minimal. Still air is a pretty good insulator.