Sucrose addition had no impact on degrees Brix

I collected roughly 12 gallons of 8.25 degrees Brix wort in my brew kettle and then added 1 pound of sucrose to the kettle pre boil.  I then took another reading and found it to be 8.25 Brix.  No change.  I expected the addition of pure sugar to increase the reading at least a little bit.

Any ideas? I usually do not add sugar to my brew. Thanks.

sounds like it just dropped to the bottom of the kettle. Heavier and colder than the wort.

Yes, I can’t imagine that the sugar actually dissolved into the wort. The other phenomena that could be at work is the fact that the upper surface of wort will segregate slightly when its still. It is necessary to freshly mix wort or collect your sample from deep under the surface to have a representative sample.

Thank you both. This all makes sense. I did stir vigorously before taking the post sucrose addition reading but maybe that was insufficient.  The post boil reading was 10 degrees Brix compared to 8.25 degrees Brix pre boil. This is perhaps a bit larger difference pre and post boil compared to my typical evaporation rate after a 60 minute boil. I expected a larger impact from the sucrose addition.