An honest plate ends with its gaps. Here are five, and they are the same ones that come back throughout the recent literature.

• What really passes into the beanDifferences are measured in the green bean after fermentation. We cannot apportion what diffused from the bath, what the bean produced itself, and what stayed only on the surface.
• Who degrades the mucilageFruit enzymes, acids, yeasts: each of the three mechanisms has a solid publication behind it, and no independent replication separates them.
• The pressures and gases of closed tanksAlmost never published, even though they govern solubility and diffusion. Everyone closes their tank in their own way.
• Reproducibility between originsNo protocol has been validated across several origins with controls. Durations circulate without their context.
• The share of selectionThe sorting and the management of drying that accompany experimental processes are almost never controlled separately.

The good news is that these are open questions and not dead ends: all of them are settled by an experiment with a control, and a few teams are starting to run them.