There is a high power fantasy setting I’ve been dying to flesh out (homebrew) but it relies on the single PC being a very competent Alchemist. Does BW have any classes that could be tailored for Alchemy or rethemed/skinned for this purpose? Ideally the PC is able to create concoctions in a variety of formats (potion, powder, pastille, ointment) with relative ease and with alarming frequency. Explaining how this is possible is easy to do with the setting but system mechanics are the hard part. Would this be possible in BW?
What exactly are you wanting these potions, unguents, &tc to do?
- A quick tonic to boost someone up for a skill roll might simple be using your skill toolkit to add helping dice [& subsequently risk exhausting the kit].
- Fancy effects like Healing potions should treated through Apothecary skill, forking in Alchemy if you like.
There are a range of skill that might be appropriate, with some overlap. Alchemy, Apothecary, Herbalisim & Firebombs, maybe some others too.
Lifepaths to take for an Alchemist might include Midwife, Barber, Student, Apothecary, Doctor, Physician, Peddler [Tweaked to be a Snake-Oil Seller], Ships Doctor, Court Doctor, or even Poisoner.
Re skinning Arcane roles like Hedge Wizard or Recluse Wizard might work well too.
Just about anything traditional potions and magic would do. Magic style potions would be harder to create given how powerful they are. I started working the idea in GURPS which is where I got the different formats from. In GURPS Alchemy is probably the most powerful PC type possible as far as well rounded character types go. But due to the creation time they are rarely formidable characters. If the time constraints were to be extremely shortened or even completely removed, given the PC has the components on hand to create the concoction in question, then the Alchemist would be a power house of super hero level. This is what I am aiming from. My problem right now is my lack of understanding regarding BW magic and system mechanics.
In the past I’ve taken the time to read through a system, then sat down to create the world and custom professions (like the Alchemist above) only to return to the game and find I needed to reread the material before I could play. Given how large BWG is I am hoping to avoid a reread if possible. So this time around I’m trying to prepare as much as possible before reading the book cover to cover. The BW is so different than anything I’ve read however that I may have no choice but to read the rulebook twice 
EDIT
Here is a listing of Alchemical Elixirs from GURPS Magic (pg 213-219). Many of these are powerful and would be hard to create either based on time, chance of success during preparation, or difficulty in finding the necessary components. But here is a good idea of what GURPS allows an Alchemist to do, which again was the source matter when I came up with the idea for the PC in a high powered fantasy setting I was dreaming up. There are more possibilities out there but this should give you a firm idea of what I’m after.
Animal Control
- Beast-Speech
- Bird Control
- Dragonslaying
- Horsemanship
Combat Abilities
- Battle
- Endurance
- Fetching and Carrying
- Leadership
- Invulnerability
- Speed
- Stealth
- Strength
Hostile Elixirs
- Aging
- Death
- Fear
- Foolishness
- Frustration
- Hatred
- Jealousy
- Lecherousness
- Madness
- Odium
- Self-Love
- Unluckiness
- Weakness
Magical Abilities
- Attractiveness
- Fire Resistance
- Flight
- Gambling
- Invisibility
- Luck
- Magic Resistance
- Pain Resistance
- Transformation
- True Sight
- Water Breathing
- Water-Walking
Medical Elixirs
- Alchemical Antidote
- Awakening
- Eternal Rest
- Fertility
- Healing
- Health
- Hybridization
- Lichdom
- Long Slumber
- Reanimation
- Regeneration
- Resurrection
- Sleep
- Tranquility
- Universal Antidote
- Youth
Mental Abilities
- Charisma
- Foresight
- Hardheartedness
- Memory
- Wisdom
Mental Control
- Drunkenness
- Friendship
- Forgetfulness
- Gullibility
- Love
- Truth
Skills & Physical Abilities
- Craftsmanship
- Hearing
- Keen Sight
- Music
I would advise against trying to exactly emulate GURPS (or any system), but you can do the magical potions with the enchanting rules from the magic burner. Some of those may be created with the “mundane” skills Durand mentions.
I think the Enchanting chapter is also available as a pdf download on the wiki.
I’d run a game or two with the system as it’s written before tweaking. Don’t try a long campaign with variant rules until you’ve had a crack at what’s been presented already.
If you want a world with lots of alchemy, the other thing you can do is just assign Obs on the fly. Someone wants to whip up a potion of X? Decide how hard that should be an what ingredients are required. Then they roll Alchemy, and if they succeed they have the potion. It’s on you to make sure they function and balance, but intent and task takes care of a lot of it. When you want to make a potion for a particular purpose, that’s the intent. Success at the task means that the potion will accomplish just that.
BW is in some ways less granular about things than other games. Look at the equipment list. It’s pretty short. You don’t need to worry about two dozens types of potions. Being able to make magical potions can be more than enough if you don’t want to delve into enchanting.
If you want a world with lots of alchemy, the other thing you can do is just assign Obs on the fly. Someone wants to whip up a potion of X? Decide how hard that should be an what ingredients are required. Then they roll Alchemy, and if they succeed they have the potion. It’s on you to make sure they function and balance, but intent and task takes care of a lot of it. When you want to make a potion for a particular purpose, that’s the intent. Success at the task means that the potion will accomplish just that.
BW is in some ways less granular about things than other games. Look at the equipment list. It’s pretty short. You don’t need to worry about two dozens types of potions. Being able to make magical potions can be more than enough if you don’t want to delve into enchanting.
Potion of Unflinching Prowess? Maybe that’s +1 Die on Steel tests. Assign an Ob, let the character roll, and have fun. In a really high powered world, maybe that’s just Ob 3 and every warrior worth his salt will drink one of those. Or it could be Ob 5 and be something for dire circumstances only.
But what will really work is alchemy on the fly. You need a sleeping draught to drug the guards? Whatever Ob seems appropriate to make it. You need a love philtre and you need it tonight to ensnare the duke in your plot? Sounds like it’s Ob 6. I hope you have some artha to burn! This can really mess things up if you’re not comfortable with difficulty, intent and task yet, but it’s also something that can be done. I’ve done similar things with herbal and apothecary skills before.
Consider having the player using a wise to let them tell you this information. The wise skills of course being subject to all the task and intent appropriateness of all skills “…made from common household goods” for example is not enough, it needs to be specific knowledge. “…Made from the blood of a dragon” might be less obscure knowledge than “…made from common flour and swampwater berries” as legends tell tales of the big stuff, if the little stuff wasn’t totally obscure knowledge everyone would be doing it.