measuring gravity of runnings - adjust for temp?

[dontbother]

I've still fairly new to all grain and sparging, yesterday this question came to mind (while in the act).

When sparging we should monitor the gravity and stop sparging if it drops below 1.006 to ensure that nasty tannin aren't extracted.... that's ok but given the temperature is high enough that the 20degC hydrometer calibration should the reading be adjusted?

I only just collected enough wort for the boil before the hydrometer was reading 1.000.

In the end I played safe and topped up with water instead of using the wort which was either at 1.000 (measured) or 1.012 (temp corrected).


Cheers,
Adam.

[mat69]

haven't you answered your own question ?
you obviously know about temp correction,so you could of kept on sparging.
by the way you said you collected enough wort for the boil,why then did you top up with water..

[dontbother]

haven't you answered your own question ?
you obviously know about temp correction,so you could of kept on sparging.
by the way you said you collected enough wort for the boil,why then did you top up with water..

It seemed equally likely that the 1.006 had already been adjusted for the typical temperature of the wort.
The wort was collected in a big jug with the hydrometer floating... so I had the choice of adding to the boiler or throwing away.

Thanks though I know for next time!

[HighHops]

This is a handy link that I use for temperature correction when sparging...

SG temperature correction link

[Kev888]

Just to mention: I have in the past damaged hydrometers by putting them in hot wort from the sparge, so I find it best from that point of view and actually more accurate to cool the wort quite a bit before measuring, and so just compensate for being several degrees out.

But I do feel the need to stop the sparge whilst I'm cooling to measure, otherwise it has progressed beyond what I'm measuring - its not too much hassle with my setup (I use a valentine arm so no ballancing to do) but it is still annoying to halt proceedings and I must admit I've sometimes wondered about getting an electronic gizmo instead. What puts me off is that if the recipe and liquor volumes are reasonable it seems very rare in my experience to actually run out of gravity before collecting the required amount of wort, so generally its a check rather than something I ever need to react to, and probably I should just let it run whilst I test.

That said, it would be different if I was trying to get the last drop from the grains at whatever resulting OG, or wanted to collect an extra batch of small beer from whatever was left in them after the main batch. In another thread HighHops suggested doing the latter and reducing it down as a way to make wort for starters etc which sounds inspired to me, so i may start collecting the last runnings in a second batch down to 1.006 - seems a shame to waste grainy goodness just because you already have the volume wanted, but it does mean I'll need to use the gravity as the stop point not just a check.

Cheers
Kev

[Brownster]

Hi, I actually taste the runnings as it gets to the weaker end, if it still tastes slightly sweet you are good to continue, any hint of astringency stop! I also back this up with gravity readings and tend to find that with an un-corrected reading of 1004 + is a good point to stop anyway due to the taste test above. Just my two penneth!

Cheers,
Wayne.