I have no clue and there is no explanation in game. I also can't seem to find a decent guide.
"The sum of the whole is this: walk and be happy; walk and be healthy. The best way to lengthen out our days is to walk steadily and with a purpose." -Charles Dickens
It is answered in-game. As soon as you hire your first alchemy peon, it gives you lore that explains the process --- says to experiment ... !
a quick guide:
1) buy or loot the potions you need to experiment. Except for aqua-vitae and aqua-regia. If you are wealthy, buy pine wood and skins. If you are poor, do the mass gather on all the slots except 1 (used to experiment and level up) for a week or 2. After a while you can swap to extraction.
2) experiment until you can gain a level.
3) level up.
4) repeat.
meanwhile, in the background, boil pine wood and make about 200 aqua vitaes as soon as you can. You will need them. If you plan it ahead, you will have acquired and condensed enough pine wood to make the aqua vitae in bulk when you reach the level that you can make it.
Comments
At each level, do the experimentation task. It sometimes give the alchemical experience as part of the completion. Then do the research task.
Note, don't do the research task through the gateway, it's apparently bugged and will leave you stuck.
a quick guide:
1) buy or loot the potions you need to experiment. Except for aqua-vitae and aqua-regia. If you are wealthy, buy pine wood and skins. If you are poor, do the mass gather on all the slots except 1 (used to experiment and level up) for a week or 2. After a while you can swap to extraction.
2) experiment until you can gain a level.
3) level up.
4) repeat.
meanwhile, in the background, boil pine wood and make about 200 aqua vitaes as soon as you can. You will need them. If you plan it ahead, you will have acquired and condensed enough pine wood to make the aqua vitae in bulk when you reach the level that you can make it.