Stop sparge at 1.010 - what if the temperature is 158f?

[Brew_Meister_General]

If my sparge water is leaving the tun at 70c/158f, do i stop the sparge when it reaches 1.010 or when it reaches 0.992? Which is equal to 1.010 at 20c/68f

 

[Subdivisions]

If you're using a hydrometer to try to read your second runnings it's not going to go too well. At that temperature I wouldn't trust it to be that accurate with the temperature correction calculators. They are meant more for within 20-30 degrees of the calbration temperature of the hydrometer.

I'd just get to my boil volume and not worry about it too much. Get a refractometer in the future to do quick measurements.

 

[specharka]

Hydrometers are fine for temperature correction, just not when there is a coincidental large temperature differential and a high gravity (> 1.070) measurement. Refractometers are just as susceptible to calibration error.

I do agree with Subdivisions on the method -- don't worry so much about your terminal mash runnings and focus on getting your pre-boil volume right. If you're a few points south of your target gravity you can always compensate with an extended boil.

 

[Brew_Meister_General]

Hydrometers are fine for temperature correction, just not when there is a coincidental large temperature differential and a high gravity (> 1.070) measurement. Refractometers are just as susceptible to calibration error.

I do agree with Subdivisions on the method -- don't worry so much about your terminal mash runnings and focus on getting your pre-boil volume right. If you're a few points south of your target gravity you can always compensate with an extended boil.

Oh sorry I should of specified that this is to avoid tannin extraction, I read that when the sparging wort falls below 1.010 then it can result in tannin extraction.

 

[specharka]

Yes I understood your intention. Tannin extraction can occur due to multiple reasons -- high mash temperatures, low mash density, wrong pH. But it should not be your primary consideration on when to stop sparging.

If you calculated your mash and sparge output correctly, you should not need to worry about extracting tannins, since your terminal gravity runnings will be in excess of that threshold. Shoot for getting your pre-boil volume right, and don't focus on getting every last drop of sugar out of the grains.