Post-boil gravity just a few points higher than pre-boil?!?

I brewed an ESB on Saturday and something I can't explain happened:

I took the preboil gravity and it came out at 1.049 (chilled to 60). After boiling and chilling, I took the OG sample, chilled to 60, and it came out...1.051?!? I had 6.75g. preboil and minus trub/hop absorption I ended up with UNDER 5g in the FV yet my gravity only went up 2 points?!?

The samples were taken as follows:

preboil, I cracked the BK valve and ran some wort from the kettle (all runnings collected and boil almost going) into the test jar, cooled in bucket of ice water.

postboil, I pinched tube about halfway thru racking into FV and filled test jar, cooled in bucket of ice water.

Any possible explanation??

It's likely the wort wasn't sufficiently mixed together. Or maybe the hydrometer really likes 1.050.

bolts said:

It's likely the wort wasn't sufficiently mixed together. Or maybe the hydrometer really likes 1.050.

Click to expand...

I'm hoping it's the former, although it's funny...most of my beers come out 1.040-1.050...

From now on I'm taking hydro samples from a mixed BK for preboil and a mixed FV for postboil.