Taking starter wort temp from 5L Erlenmeyer Flask

[Gustatorian]

Can anybody recommend a thermometer that will reach to the bottom of a 5L Flask without contaminating the starter wort? All of my thermometers are too short.

 

[Jwin]

IR thermometer?
Cheap ones are around $15 on Amazon or harbor freight

 

[Gustatorian]

IR thermometer?
Cheap ones are around $15 on Amazon or harbor freight

Won't that take the temp of the glass around the wort and not the actual wort?

 

[LLBeanJ]

I am of no help here, but curious why you need to take temp of starter wort?

 

[jcav]

Are you wanting to know when it's cool enough to pitch the yeast? You can shoot down and into the top of the flask to at least get the surface temp with an infra-red thermometer. Also how tall do you need it to be? They have many tall glass ones that come with plastic cases used in the photo industry and in labs that would work.

John

 

[LLBeanJ]

I don't do many stove top starters these days, but back when I did I would just cool it down in a cold water bath in the sink for about 10 minutes and then feel the outside of the pot/flask with my hand to gauge the temp. It's pretty obvious once it's cool enough to pitch yeast and definitely not necessary to use a thermometer. I used one for my very first starter and it was a total PITA, so that was the first and last time I bothered to use one. Once it's cool to the touch, it's safe to pitch.

 

[day_trippr]

Won't that take the temp of the glass around the wort and not the actual wort?

I use a Fluke IR gun, and have checked it against a direct read with my Thermapen, and they're within tenths of a degree F wrt the liquid temperature.

Lab flask bottoms aren't thick and transfer heat readily...

Cheers!

 

[mengelma]

ThermoWorks has a 1 foot and a 2 foot version. I have the 2 foot version, plenty long enough for a 5 Liter flask and a 15 Gal mash tun.

 

[doug293cz]

Won't that take the temp of the glass around the wort and not the actual wort?

Just shoot down thru the neck opening to the liquid in the bottom.

Brew on

 

[Spartan1979]

I use a thermometer similar to this:

https://www.amazon.com/dp/B003JEKSLA/?tag=skimlinks_replacement-20

I can't remember where I got the one I use.

 

[passedpawn]

Just get the temperature of the glass with an IR gun. $14 on amazon. If you swirl the contents (or it's on a stir plate), and you don't have any cold wind currents outside the flask, you're going to get the temp of the liquid inside. The glass will be the same temperature.

Thermal conductivity of air is horrible. Thermal conductivity of wort is about 20 times as much as wort. Thus, the glass will read very close to the temperature of the contents.