Floating Thermometer question, kind of urgent

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

BrewRI

Well-Known Member
Joined
Sep 28, 2009
Messages
160
Reaction score
3
Location
Narragansett, RI
I'm brewing my first partial mash right now and I was wondering if a floating thermometer needs to be fully submerged in the water to give an accurate reading. I have about 2.60 gallons in a 10 gallon boiling pot so its not actually floating its resting more than anything. I was thinking if it's touching the bottom it could artificially increase the temperature. Would it be better to get a tall glass and fill it with water from the pot and float the thermometer in that instead?
 
Yes, letting it rest on the bottom will allow conductive heat from the pot (and by extension the fire or electric burner) make your temperature read higher than it really is. It is best to suspend it in liquid. The thermometer should be filled with little beads that take a minute to equilibrate with the surrounding temperature. Just hold it there for a minute and let it stabilize and then take your reading.
 
Mine often rests on the bottom of the pot. I haven't ever made any temperature adjustments as a result. I keep it off the bottom if possible but sometimes theres just not enough water in the pot for it to "float".

I guess I don't really know if it affects the reading. I brew all grain and have never missed a mash temp (+/- a degree or 2) as a result of heating strike water and using thermometer reading when resting on bottom of kettle.
 
If it isn't floating, I hold it above the bottom of the pot if the heat is on.
Don't want to risk an inaccurate reading.
When taking mash temp readings though, I just let it sit in my mash box submerged - since it's not on the heat I can get a good reading without having to stand there.
 
Back
Top