OG Discrepancy: Post Boil vs. Post Knockout

[threeviews]

Thank you to all who have contributed. With all the discussion posted until now, which reading do I ultimately trust?

1 - The hydrometer (i.e. post H.E.) - This is also negating the stratification I noticed at the fermenter's sightglass (very, very light at the top with the color increasing greatly approaching the cone). The sample port of our fermenter was positioned at the very top (probably less than a bbl) of the wort level...thinking back, the wort of this batch into the fermenter was ~64F while the hydrometer was rated for 68F. However, that still wouldn't correlate to the discrepancy between 1.078 (post H.E.) and 1.088 (flameout/whirlpool)

2 - The refractometer (i.e. pre knockout) - The readings I reported up until post knockout were all copacetic (and the numbers of our next batch all matched...both pre H.E. and post H.E.)

3 - Some educated guess between the pre and post H.E. readings...perhaps the wort was somewhere between to the two readings, say 1.082-1.084?

NOTE: Moving forward, I will grab a post-boil, hot side sample for use with a hydrometer...but perhaps someone else has some more feedback.

Thanks again,
Brent
Wet Ticket Brewing

[Jer]

Neat! And here I am, just using ice from the ice maker like a sucker.

I tried ice too....the thief is worth the 150$ cost. No mess, you can time the chilling and get a fairly consistent temp, and it's yet another piece of unnecessary but beautiful stainless steel!!!!

[Jer]

Thank you to all who have contributed. With all the discussion posted until now, which reading do I ultimately trust?

1 - The hydrometer (i.e. post H.E.) - This is also negating the stratification I noticed at the fermenter's sightglass (very, very light at the top with the color increasing greatly approaching the cone). The sample port of our fermenter was positioned at the very top (probably less than a bbl) of the wort level...thinking back, the wort of this batch into the fermenter was ~64F while the hydrometer was rated for 68F. However, that still wouldn't correlate to the discrepancy between 1.078 (post H.E.) and 1.088 (flameout/whirlpool)

2 - The refractometer (i.e. pre knockout) - The readings I reported up until post knockout were all copacetic (and the numbers of our next batch all matched...both pre H.E. and post H.E.)

3 - Some educated guess between the pre and post H.E. readings...perhaps the wort was somewhere between to the two readings, say 1.082-1.084?

NOTE: Moving forward, I will grab a post-boil, hot side sample for use with a hydrometer...but perhaps someone else has some more feedback.

Thanks again,
Brent
Wet Ticket Brewing

Trust the readings taken from the same calibrated hydrometer that are all taken at the same temp (+/- a couple degrees). Using different instruments, or different temps, is apples and oranges.

-J.

[beerbeer95648]

Trust the readings taken from the same calibrated hydrometer that are all taken at the same temp (+/- a couple degrees). Using different instruments, or different temps, is apples and oranges.

-J.

Agreed, hydrometers are way less fickle. Trust the hydrometer.

[jebzter]

Had a fun one come up last week. Did a pre-boil gravity check, everything was good. Post boil was a different story, checked all the possible sources of water ingress into the beer, everything was sealed up tight. Not to mention that if I added enough water to get the gravity as low as it was, my tank would have overflowed. The lesson from this is always to check your test equipment against a standard, got my much more expensive hydrometer out that only serves as a back up and checked the other one against it, sure enough it was out of calibration. A crack formed and allowed liquid in, throwing off the balance of the hydrometer between the start of the boil and the end.

[NHBrewer23]

Glad to hear it! That should make sleeping at night a little easier. Cheers!