Specific Gravity Adjustments for Temperature

[MrC]

I've recently started fly sparging and according to HowToBrew, when fly sparging:
you should stop lautering when the gravity of the runoff falls below 1.008

I stopped lautering when my hydrometer said 1.008, no adjustments made for temp. I was hoping for 26L of runoff by I only got 23L.

Should I be adjusting the gravity reading to cater for the temp of the runoff?
Did I stop lautering too soon?

Also, should ALL gravity reading be adjusted for temp (OG, FG, etc)?

What do you do?

[jt]

Also, should ALL gravity reading be adjusted for temp (OG, FG, etc)?

I always adjust if it's more than a couple of degrees either side of the calibration temperature

[Stu McKinlay]

Yes - always adjust.

1.008 at 60c (140F) is actually 1.021 according to this chart.


The easiest way to do this is use a refractometer. This is also simpler for pre-boil gravity etc. I've not got one but I would like one... it's down my list though. The stainless conical leap-frogged the conditioning chest freezer + fridgemate, which still tops my list.

[denimglen]

Agreed.

Agreed, but 1.023 if your hydro is calibrated for 20C instead of 15C.

Agreed again, I use a refractometer for everything pre-ferment, after that though it's pretty useless.

I rock one of these in the garage with Beersmith. (Hopefully) Far away enough from waters harm.

[MrC]

Thanks guys. It seems I've been missing the point in this department.

I guess it won't make much difference to my OG & FG differential which are usually within 2 degrees of each other. It's only used for ABV% & attenuation tracking anyway. It will certainly make a difference to my fly sparging though. I guess that means I tipped out approx 3L of good wort :(

[jt]

Three litres ?
That's a good evenings drinking Mr C !

[MrC]

I know, it's good beer too. My best yet according to my wife.

[Barry]

promash has a calculator for temperature adjusted gravity measurements. click the "hydro adjust" button.

[jt]

I don't have access to promash in the garage, just stick a chart up on the wall and refer to that when needed

[Barry]

ha, stick a chart on the wall. I might do that, then I could blindfoldedly throw darts at it and have my brewing become 50% more accurate!

[jt]

Ha .. no, new game - Throw the hops at the kettle !

[James P]

Sticking a chart on the wall is also much safer than a laptop next to the water...... trust me on that one.....

[jt]

Pro mush eh ?