pre boil gravity and bost boil gravity = Same

[latProd]

Hey guys,
Just brewed an english pale last night. I took a gravity reading pre boil that was 1.050 (at 20 degrees celsius). I was expecting to see ATLEAST 10.56-58 after the boil. I realized I had used too much water, so I boiled it for an extra 20 minutes before the 90 minute regime. (nice rolling boil throughout).
I cooled it down to 20 degrees celsius, aerated the wort so it was foaming like crazy, pitched the yeast, stirred it in and realized I forgot to take a gravity reading. So I did. And again, 1.050. I calibrated my hydrometer a couple of weeks ago, so I have no reason to assume it's faulty.
How is it possible to have the exact same value after 115 minutes of boiling? I could see from the edges in the kettle that it had definately evaporated...
Any ideas on this? Never seen that before

 

[Gnomebrewer]

I find gravity readings, especially pre-boil, to be very inconsistent (a lot of stratification). Even if I mix thoroughly, there seem to be high and low gravity patches. Even in the fermenter, I often find a 0.005SG difference when taking a reading from the tap at the bottom vs. a scoop from the top of the fermenter.

 

[latProd]

thanks, I see what you mean. Wasn't aware of those differences. However I'd think I would atleat see some kind of difference ...

 

[Natdavis777]

I have found it best to take gravity readings in the BK. So as the boil starts, I pull my Pre-boil sample. You can take it before this time, but I recommend giving the wort a good stir. I then take my Post-boil sample right before killing the boil. Again, this ensures everything is evenly in solution due to the boil. If you used a yeast starter, the liquid of the starter can lower the OG slightly due to the liquid in the starter, but I cant see it diluting to a point where its the same gravity after a 90min boil.

Since wort is a homogenous solution of a dissolved sugar liquid, it shouldnt stratify. But I have experienced this is a few beers, where I actually watched my gravity go backwards. In these few scenerios, I was pulling my Post-boil reading from the BK after the wort had say stagnant for 10+ minutes. I always was pulling from the top.

I have yet to run into this issue since practicing my current process of pulling my pre and post samples @ the start and end of the boil process

 

[latProd]

Hmm I will try that next time, thanks man.
I have a boil kettle with a tap at the bottom, So I always use that.
I always cool to 20 celsius, not sure if that is good practice...but there you go.