stupid physics question

[fluketamer]

maybe.

i never left my ispindel in a FV during cold crash or checked gravity after terminal but you can see the gravity is inversely proportional to the temperature.

at 37 degrees, my kolsch gained back 6 gravity points and now comes out to about 3.87 abv .

i know liquids contract when cold and get denser and the gravity goes up but the alcohol didnt go anywhere right.

its still 4.8 abv right?

 

[homebeerbrewer]

I would assume that the ispindel is calibrated to a certain temp. If you took your reading at the calibrated temp, it'll be accurate. The ABV won't change with the different temps, but the reading will.

 

[khannon]

Yes,

This is why we take SG readings at a consistent temp, or use a calculator. https://www.brewersfriend.com/hydrometer-temp/ is what I use.

 

[fluketamer]

thanks that makes more sense

 

[VikeMan]

at 37 degrees, my kolsch gained back 6 gravity points and now comes out to about 3.87 abv .

At colder temperatures, the beer volume does decrease and gravity thus increases. The change from (say) 68F to your 37F would change the "real" gravity by a couple points, but nowhere near 6. I've never used an iSpindel, and haven't really looked much at the design, so I can't say if I'd expect the difference of the other 4 points or so to come from design (though my gut feel guess would be no).

ETA: That said, your alcohol didn't disappear.