hydrometer question

[missing link]

I know that using beersmith, my hydro sample doesn't have to be at 60 degrees to take a reading because beersmith adjusts. My question is how far from 60 degrees can you be and still have the hydrometer adjustment be accurate.

My last AG batch I made some mistakes due to lack of planning.

I collected 9.5 gallons when I only wanted 8.5.
I took a pre-boil hydro reading at 204 degrees, adjusted in beersmith and got 1.037, my target was 1.038 so I figured I did great and just made to much wort.

Boiled hard for 90 minutes down to 7.5 gallons and cooled. At 70 I took another reading, entered it into beersmith and got 1.030. I am more inclined to beleive the 1.030 reading than I am the pre-boil reading. Obviously 1 of them is wrong because the gravity should increase with boiling.

Something tells me the extra gallon of wort caused me to be to low on my gravity.

Anyway, my major question is at what temp do you take your pre-boil gravity reading?

Linc

 

[Yooper]

I've found that anything over about 90 degrees is terribly inaccurate when adjusted. So, I take the sample, and stick the hydro jar in a round pitcher of ice water and wait until it's under 90 degrees, and then use the adjustment tool. It's kind of a pain to do this, but I learned that it's the best way to get some accuracy.

 

[missing link]

It's easier to get to 90 than to 60. I was just wondering where the reliability of the adjustement stopped and it seems you answered that question for me.

At first I said hey no need for a refractometer or waiting for the sample to cool, just enter in beersmith and go. But 2000 degrees also works in beersmith!!

I'm trying to hit my pre-boil volume and gravity everytime, or adjust before boiling begins so I guess I need to hold off on initiating the boil until I've cooled my sample down below 90.

Thanks for the input.

Linc

 

[DonkeyShoes]

204 F is really far from the 60 F calibration of the hydrometer. Even though BeerSmith adjusts for the temp, the variance probably increases as you get further from the original calibration temp.

I have not started AG (this Sat is my 1st), so I don't take pre-boil gravity yet. I would think that you could get your preboil sample at any temp you like and just let it cool on the counter or in the fridge until it gets down to 70 or 80 F.

A good way to find out how the heat affects you reading would be to heat up some water in the microwave to near boiling and test it with you hydrometer. You could leave it out on the counter and take note of how the reading changes as it cools.

 

[Bobby_M]

Don't forget that the preboil wort can be stratified because it went in at different gravities throughout the sparge. It's possible you weren't fully blended when you pulled the first sample.

Though I do agree that temperature correction error can be a factor as well.