Final answer:
The most difficult part of understanding bread and pastry production is capturing wild yeasts from the air and ensuring a successful fermentation process.
Step-by-step explanation:
The most difficult part of understanding bread and pastry production is likely the process of capturing wild yeasts from the air, as mentioned in the historical context. Before modern yeast strains were developed, bakers used to rely on capturing naturally occurring yeasts to make bread. However, this process was challenging because many batches of dough ended up being discarded due to inconsistent or undesirable fermentation.
This difficult step of capturing wild yeasts required a lot of time and effort to ensure a successful fermentation process. Bakers had to carefully observe and experiment with different batches of dough to find the right yeast strains that produced the desired flavors and textures in the bread. It was a laborious process that required knowledge, experience, and a bit of trial and error to master.