Guide for how to accurately determine percent increase in volume for bulk fermentation

Toast

Greetings.  Long time baker, but first time on this forum (from Bucks County PA). I've picked up a lot of useful information and perspectives here and I figure it's time to give back.  I saw a post awhile back in which a newer baker asked how to determine when their bread has risen by a given percentage during bulk fermentation.  Anyone who's watched dough rise in a wide bowl knows that it's really guesswork if done by eye. Below is Google Drive link to a PDF I created showing how to do it simply and accurately every time.

To forestall a post saying I could just use a dough bucket with volume markings, I prefer a ceramic bowl because it's much easier to do coil folds, and it releases the dough far easier compared to a plastic bucket (without breaking the skin on the upper surface).  I do, however, use a dough bucket for my initial mix until bulk fermentation starts, at which point I transfer to my bowl.

Art

https://drive.google.com/file/d/1UNIL_58VgTyClE-qe1MVYUY04iM3eQQj/view?usp=sharing

Toast

Nice work.   The density of water does vary with temperature but according to https://www.csus.edu/indiv/m/mackj/chem1a/docs/h2oden.pdf  between 0 - 30 ℃ the variation is in the 3rd decimal place, ie., who cares (for bread baking).

I use a marked 3.5 l / 4 qt square plastic container, two of which conveniently fit in the B & T proofer; my 4l cylindrical containers are just a little too tall.  The 3.5 l will generally manage 2 kg of dough.  

I used to snicker at Reinhart for all the spray oil he uses, but it turns out that a spritz of spray oil in the plastic containers saves a lot of scraping in awkward corners (which isn't that bad with a plastic bench scraper).