Post Boil Gravity

[WildPirate]

So I just brewed my first all grain yesterday. I took a pre-boil reading and got 1.058, my post boil reading was 1.054, am I wrong or is this a little counterintuitive?

 

[chapa]

Hydrometers are calibrated for a certain temp, usually 60, so if you took the reading at a higher temp, it could have effected the OG. Other than that, I don't see why it would go down. I know it was all-grain, but you didn't top off with water at all, did you? Sometimes its hard to get an accurate gravity reading, when its not mixed very well. Shouldn't be an issue with all grain though. Very strange.

BTW I see you are in STL, have you checked out any of the local clubs? I'm in the St Charles area, so I go to Ofallon meets "Garage Brewers Society". Really good time, and you can get feedback on your brews, as well as try other homebrews...just be warned, those little samples add up

 

[Golddiggie]

How did you measure the gravity, and what was the wort temp when you took the readings? If you used a hydrometer, they're only reliable when under ~80F. Often the closer you get to 60F the better you'll be (with most calibrated at 60F)... If you used a refractometer, then does it feature ATC? IF not, then you need to offset for the temperatures of the wort you took a reading of...

BTW, I used my refractometer on it's first batch last week... My pre-boil wort gravity was on target, as was my post boil gravity... Can't see ever trying to use a hydrometer for those readings ever again...

 

[WildPirate]

BTW I see you are in STL, have you checked out any of the local clubs? I'm in the St Charles area, so I go to Ofallon meets "Garage Brewers Society". Really good time, and you can get feedback on your brews, as well as try other homebrews...just be warned, those little samples add up

I'll have to take a look thanks!

As far as my samples, my pre boil was cooled in the fridge to exactly 60F and my post boil was closer to 64F and I used an online calculator to adjust for a correction.

Perhaps my post boil sample wasn't mixed very well. Any suggestions for future brews? I suppose i should just bite the bullet and buy a refractometer.

 

[Golddiggie]

Why did you feel the need to correct the readings? The hydrometer I have only mentioned adjusting the reading when you star getting over 70F... Even then, it's only by .001, which is tiny...

IMO, a refractometer makes things so much easier on brew day... I'd recommend getting the one Bobby_M lists, since it's not expensive AND designed for measuring wort. Just follow the operations manual (single sheet of paper) and you'll be fine... I calibrated mine on brew night and it worked out great...

 

[WildPirate]

I corrected the last reading because the sample was at 74 not 64 what was a typo on my part.

 

[erikpete18]

Unless you topped off with water the boil would have mixed everything up real well so your post-boil reading should be accurate. What might have happened is if your pre-boil wasn't mixed well you might have drawn from the bottom where the first-runnings were and got a higher reading than it should have been.

 

[kanzimonson]

Whether you're using a refractometer or a hydrometer, you still have to mix the wort really thoroughly before taking a sample.

Don't just get it swirling around - pull the dense wort up from the bottom, stir clockwise, then immediately break the current and stir the other way. Do this for at least a whole minute.

Nothing sucks more than a bad reading throwing you off. I brewed a weizenbock recently and I was never totally sure about my preboil reading. I took it like 5 times, plus another 5 throughout the boil. I ended up guessing and crossing my fingers on how much DME I needed to add... luckily it was right on, but what a stressful brew day.