I use one of these jars for pizza, but not for bread, where I am able to measure the dough volume in the bulk container accurately.
You can see the spy jar I use in this post:
Temperature was the same, by the way.
It would be interesting to know of any other results our community might have.
Lance, I have had occasional bakes where the aliquot jar rise seemed to be much slower than I would have expected. It doesn’t happen often, but it has happened.
The difference in rise that you saw between the aliquot jar and the main dough seems really out of whack. I don’t have a bulk container that allows me to accurately estimate the rise so I don’t have that information to share. I do wonder if your results are repeatable or if it was an one off.
Benny
Maybe some mixing issue? The sourdough starter or the yeast was not uniformly distributed in the dough?
Temperature can also be an issue, if the dough temperature after mixing was higher than the temperature of the spy jar or the temp of the surrounding air. The small quantity in the spy jar cools down much faster than the bigger dough in the container.
The spy jar was kept directly next to the main dough in an insulated proofing box, so I am confident there would be little temperature difference.
Mixing was in a spiral mixer, so the dough was well mixed.
The only thing I can think of was that I was actually using the Mk 1 version of my spy jar - same dimensions, but with a fixed base. It's surprisingly difficult to get the slug of 71% hydration dough down to the bottom of the tube! An oiled plastic straw pre-inserted into the jar helps to provide an air escape, but inevitably there was some smearing of the dough onto the tube sides on the way down. Perhaps this sticky surface made it more difficult for the dough to rise?
I'll try the experiment again sometime with my Mk 2 spy jar where I can pop the dough in from the bottom of the tube.
Lance