Some random ideas, not necessarily to do with alchemy or potions specifically:
- Okay, the ahuizotl is a mythical creature from Aztec folklore. It is a doglike creature with slick shiny skin and a human-like hand at the end of its tail. Its commonly found around rivers or watery areas where it uses its hand to drag people below the water to drown them. Oh, and it steals their eyes and fingernails. It doesn't eat their flesh, just drowns them and steals their eyes and nails. Its also known for being able to imitate the sound of a baby crying, it cries like a lost child, people come to investigate, then it drowns them and steals their eyes.
I bring this up because I had heard about this creature shortly before playing Skyrim and I noticed that the player in Skyrim goes around eating alot of wierd stuff for alchemy. I figure an alchemy themed game could make use of a weird monster that steals human eyes and fingernails. Maybe it turns out that to make a specific potion you need the eyes and nails of a human... or the creatures harvest humans for those ingredients. Finding a potion that does the same thing without human parts could put an end to 'human poaching'.
2. Alchemy fairies - Bit of a stretch, but I know in alot of stories you'll have magical creatures that do things like paint the rainbows or tend to the creatures and plants of the forest. Could be that there is a specific type of fairy or magical creature that makes potions. The protagonist could start out with a fairy like this who helps them out at the beginning. The process of "automating" the potion making process could just be a case of creating a recipe and then recruiting more fairies to help with the mixing and such (have one fairy grind the powder, another boil the broth, another mix the results, etc).
Could well be that these fairies go around gathering all sorts of weird things for their potions, and some of those potions are used for things like giving leopards their spots or turning rocks into rubies (or coal). Things that no human would expect the potions to do or perhaps even care for. However. those same potions or ingredients can do useful things. Or could just as well be that the fairies can tell if something is 'magical' or not but they don't know exactly in what way. So fairies grab everything from rat whiskers to fire opals to orphan tears and collect them in the hope of figuring out what to do with them. The player then can use them to make potions (to help themselves) and the fairies help him collect more ingredients or make potions.
Could even provide a motivation of sorts. The fairies know of some cave with moss they use for growing healthy eagle feathers (or whatever) but monsters have taken over and they need help getting the moss. Failure means that the eagles won't be able to fly as fast and far this year. The player could easily say "Oh yeah, what do I care if a bunch of birds have problems." until they realize that "Wait a sec... this moss has something to do with feathers... and flight! Can I use this to make a flying potion or will it just grow hair or something weird like that?".
3. Song and poetry - I dunno about you, but nothing says "magic" like a bit of rhyming. Could very well be that in this world many potion recipes are not written down but handed down through word of mouth and they use rhymes or possibly riddles or stories to remember them. The player could get rare recipes or hints about ingredients through old songs. (Just letting you know, if you need any help making nonsensical rhymes or random weeds or whatnot then feel free to message me and I'll be glad to help with that).
4. Elements, vitamins, toxins and magic - A sort of basic idea on how some potions might work.
Elements are trace minerals that the body can use to help itself. For example, modern table salt contains iodine in addition to the sodium chloride. Iodine Deficiency
is a condition where a person doesn't get enough iodine in their diet and it can result in mental retardation. Its usually found in inland areas because iodine can be found in seafood naturally and you can't really grow iodine foods in areas that don't have it naturally in the soil. Basically, elements are tied to rocks, water, and the environment and become part of whatever grows there.
Vitamins (and proteins as well) are parts of an animal or plants chemistry that the body uses upon eating the thing. Eating citrus fruit gives vitamin C, eating organ meats give various proteins and whatever. Probably has little to do with proper alchemy, but there could be something about extracting specific vitamins and such for making potions or things. Maybe using "vitamin potions" involves taking them regularly and as a result boosting your natural stats.
Toxins are compounds that plants and animals make specifically to alter some other creature, usually to kill them somehow. Toxins can do thing like slow or speed up heart-rate, cause hallucinations, or do other things. Alchemy that involves these things tends to isolate the toxin and perhaps break it down into its components get a specific dosage. The difference between a poison and a medicine is basically the dosage. A medicine that lowers blood pressure can become deadly if overused.
Magic of course really depends on how you use magic in the setting, but I'm sure from a traditional sense the effects should be tied to whatever it came from. Say, the hooves of a mighty boar could yield a magical effect that roots a person to the ground (or alternately increase their strength). Invisible creatures would have inviibility magic in their skins and so on. The trick to making a magic potion could well involve somehow breaking down whatever tissue the magic is bonded to, and trying to transfer the magic over to the person drinking it. Specifically, move the magic from one part of the origional life form (from a trees bark, or a birds feathers) into the recipient (a persons skin or maybe their hands). Doing that could require mixing in various elements, vitamins, or toxins that target the part of the recipient.
So... if you want a potion of strength, you might have to take the hoof shavings of a minotaur, boil them into a paste, then mix it in with milk or something that you know will go into the bones and muscles. The "strength magic" was originally bound to the minotaur hooves, then it was transferred to the milk, and the mild once drunk was reduced to its vitamins and sent into the bones and muscles by the body. If you were to mix minotaur hooves with say... carrots or something then the strength magic would presumably go into your eyeballs and that wouldn't really help anyone.
Other recipes might involve infusing invisibility magic into a salve so it can be easily spread on the skin (where it will be most useful) or maybe the invisibility magic gets mixed with fish oil and consumed with the logic that the vitamins will get sent to the skin naturally and become a more lasting effect.
Soo... alchemy could have several steps.
Find something with a magical effect in it. This could be a mineral (evercold ice), vitamin (glowfruit juice), protein (rocktroll skin), or a toxin (nightmare viper venom).
Break said ingredient down to isolate the desired magical effect without destroying it or letting unwanted effects remain.
Mix it with another compound to bind the magic to, preferably one that can be easily absorbed into the body and specifically the part you want it to go to.
Extract the desired compound from the mixture and distil it into a potion.
More complex potions might require adding magical enhancers that complement the desired magical effect. Or you may need a specific process to break down the original ingredient. For example, a dragons stomach lining has a magical effect that renders it completely immune to fire damage. Even if you can get a sample of that lining, you could only break it down using acids or other reactive compounds since boiling water would have no effect on it. Similarly, a potion of invincibility would require a starting ingredient that was itself invincible... so you could never grind up the ingredient to make a potion of it. You could however get something invulnerable to everything but heat and melt it down... and another invulnerable to all but acid and try mixing them together.