Heat = movement

Keep your hide + bark-liquor in a warm place
Ideal temp is 75 F or 25 C - very warm!
If we hit 65-70 F or 18-21 C we are doing great. Tannins don’t much move below 60 F or 15 C.
You can scoop out a gallon of bark-liquor, heat it up, and put it back in with your hide
An aquarium heater will keep liquid warm; be careful to not let it touch the hide

Movement = movement

Underwater is life

Keep the hide submerged under the surface of the liquid
Use a rock if a hide floats - and place the rock on the wool side to prevent accidental dyeing of the leather (rare but possible)
Oxidization from air exposure can lead to discolouring and, eventually, mould

Life is messy

Wear dark or black clothes - or your hide apron - when stirring the hide
Keep a towel underneath your hide bin to catch spills and to place your rock onto
Have paper towel nearby to wipe your hands
Tannins are dyes; they can get everywhere

Mould is everywhere

Eventually you will probably see a “bloom” on top of your bark-liquor, especially in warm climates
Fewer tannins in solution + more sugars in the bark itself (species-related) lead to mould blooms
Scoop the bloom off with a spoon/yogurt cup/strainer before it grows too much

Keep tabs on things

If you have a barkometre, measure it after a few days and see if your liquor is weaker (first make sure you’ve measured before + after you put salt in)
If you are totally analog, you can fill a small jar with bark-liquor on Day 1 or Day 2, then scoop a new jar into the bark liquor on Day 5 (before strengthening) to see how different the bark-liquor looks five days apart. Do this as often as you’d like.
From Day 5 forwards, cut a piece of hide off and look at the cross section (sideways) to see how far tannins have absorbed into the hide
You can keep a log + write down how much bark/extract it takes to tan the tan your hide

Bark-liquoring Tips