
Alchemy is one of two manufacturing professions powered chiefly by herbs. Herbs make potions, elixirs, and flasks. In addition, certain fish and metals and gems can be combined to make elixirs or transmutes. Overall, you can make money with alchemy, though you’ll end up making as much or more with herbalism. But there are some definite advantages to alchemy that set it apart.
Raid supplies are the most common use for alchemy. Healing and mana potions, high level flasks and elixirs, these can all help make or break a large raid and guilds tend to buy in bulk, especially if they’re running last minute or don’t have people to make the supplies for them. Mostly this means checking out the auction house on a weekend and seeing what flasks or elixirs are selling the most. Then just grind away on those and throw them onto the AH to test.
Health and mana potions, even with the recent limitations, still dominate in terms of money making. If you can make these in bulk, you’ll do fine.
Transmutes have recently gotten a huge boost with the advent of the Cardinal Ruby and a few others like the Eye of Zul. Both recipes have 24 hour cooldowns, but are well worth the gold spent to acquire materials. If you can transmute or gather your own eternal fire for the ruby, you’ll make almost 100g on the transmute. Forest emeralds are relatively cheap (7-8g a pop low price) and Eyes of Zul go for around 75g+.
And if you happen to have a miner as an alt, you’ll be able to source your own materials for things like Arcanite, which no longer has a cooldown to transmute at all.
Specialists in alchemy have the option of proccing multiples of a potion, elixir, or transmute they’re making. Transmute spec is the easiest to get, though the proc rate is low and combined with a longer wait time, may seem like it never works. Potions and elixirs have better rates and are very fruitful, though you’ll need a group of dedicated people helping you get those specializations.
Learn to fish, it will save you time and money in the long run and it’s a great secondary skill to have anyways.
Alchemists also have a few profession only items they can take advantage of. Mad Alchemists Potions, Endless Healing Potions, Endless Mana Potions and alchemist stones (High level trinkets that increase stats or attributes as well as giving a potion effect boost) all contribute to making this profession useful. I also hear that there will be a lot more coming in the next expansion and patches.