Booze Barrel questions

-Does fermentation reset if you insert new ingredients into a barrel that has already been fermented up to a point?

-Would adding new ingredients just set it backwards depending on how much you added, and how much is already fermented in the barrel?

-Does the combined number of ingredients increase the time for fermentation?

-Does fermentation occur while the barrel item is in your inventory, or only on the scaffold with no tap?

-Is there a way to view the progress and ingredients currently in a batch without disrupting it? (drains 2L every time you check, 1 for the tap, 1 for the mug)

-How do you know when Rum has fermented properly? (The mug simply says "Rum" with no indicator of readiness.)

I was hoping that some of the players may have figured out these things already, I don't know if any of them are worth being posted into the Q&A.
Because of the long periods of time and lack of indicators, it's hard to do effective testing. These aren't immediately clear, are irritating to test, and if someone already suffered to figure it out, it would be a shame to repeat that..