Thermal expansion "myth"

[jmf143]

The "myth" being that it needs to be accounted for in brewing, not that it doesn't exist.

The only times in my process that I'm interested in the volume of warm/hot wort are 1) measuring my runnings (in which case my wort is "warm", not near boiling so the 4% expansion factor is meaningless and 2) at the end of my boil, in which case I'll chill my wort first then measure the volume. In every other case where I'm measuring liquid volumes my measurments are of cold/room temp liquids.

Am I missing something here?

 

[Beerrific]

I measure the volume of the wort as it boils to make sure I am boiling off what I am expecting and adjust the flame. You need to take it into account then.

 

[bottomofthebarrel]

Frylock: Knock-knock. Well, I hope I'm--OH MY GOD!
Meatwad: Frylock, what a pleasant surprise. I'm just finishing up my symposium. You've met my colleagues, Professor Vanessa and Dr. Dewey.
Frylock: Yeah, what happened to your body, man?!
Meatwad: Well, it's obvious, isn't it? Thermal expansion.
Frylock: No, it's not thermal expansion. I know what thermal expansion is.
Meatwad: Okay, fine, I'm sure that you do.

Meatwad: Let's see.. how can I explain this without blowing your mind..
Frylock: Oh yes, please. Dumb it down for me.
Meatwad: Heisenburg's Uncertainty Principle tells us that at a specific curvature of space, knowledge can be transferred into energy--
Frylock: Heisenburg's Uncertainty--
Meatwad: ..and this is key now.. matter.
Frylock: No it does not!
Meatwad: Well, some people struggle with Heisenburg. Look, here's a toy. It goes up and down on a string. Doesn't that look like fun?

 

[eelpout]

any ATHF reference draws my complete attention.

Yea I measure cold and let 'er go. There must be other things that also affect its expansion and contractions that we aint checkin for.

 

[JetSmooth]

I measure the volume of the wort as it boils to make sure I am boiling off what I am expecting and adjust the flame. You need to take it into account then.

Yeah. I "gain" a good half gallon as my water heats up. So I figure I've boiled off enough when I am within a half or quarter gallon of my post-boil amount. Seems to work out most of the time. Brewing software really helps, though. I don't sweat it.

 

[jmf143]

I measure the volume of the wort as it boils to make sure I am boiling off what I am expecting and adjust the flame. You need to take it into account then.

Good point - I see now that if I haven't boiled off enough liquid I would want to know about it. I'v never had that happen but concede that it could occur.

Thanks Beerrific!