In Wrath, a minority of Recipe items can be found as loot, whereas earlier levels of Alchemy recipes would sometimes be purchased from vendors or earned as reputation rewards.
There are 69 Wrath Alchemy recipes known so far: 38 trained, 13 discovered through Northern Alchemy Research, 12 discovered through transmutes, 1 from a quest, and 5 that drop from specific mobs.
Thirty-eight items are learned from a grand master Alchemy trainer in Northrend, in addition to the passive skill of Mixology (requiring 50 skill) that was also introduced with Wrath:
In addition, the following recipe was introduced in patch 3.1, but it cannot be learned from Northrend trainers; head to an alchemy trainer in Shattrath or in a capital city in Kalimdor or Eastern Kingdoms to learn it.
The discovery system grants a chance of learning a new recipe when making Alchemy products.
Potion, Elixir, Flask discoveries
In Burning Crusade, making potions, elixirs, or flasks with BC ingredients could possibly randomly teach one of five flask recipes or a potion recipe. In Wrath, it does not appear to be the case that new Wrath recipes are discovered by making Wrath potions, elixirs, or flasks. However, reports show that you do have a chance to discover one of the six discoverable Burning Crusade recipes when making Wrath items.
The main source of new recipes in Wrath, aside from the trainer, is by creating the Northrend Alchemy Research item (which is trained at 400 skill). Once trained, the Research item can only be created once every three days (seven days prior to patch 3.0.8). Each time it is made, it gives a chance to discover a recipe (or can also fail), and regardless of whether or not a new recipe is discovered, it will also produce several of a random Wrath elixir, potion, or flask.
The official patch notes for patch 3.0.8 noted that "the chance to discover a Northrend transmutation has been increased" but there is not yet sufficient data to determine the discovery rate. Most alchemists report that they do learn a new recipe most of the time.
Thirteen recipes are known to be discovered (based on information in the official Blizzard profession forums, and Wowhead and Thottbot comments).
When performing any Wrath transmute with a cooldown, the alchemist has a chance of discovering a new transmute recipe. As of patch 3.3, the epic gem transmutes and eternal conversion transmutes are the only ones with cooldowns. All of them have a 20 hour shared cooldown. The Transmute: Titanium cooldown was removed in the same patch.
Twelve transmute recipes are known to be available to be discovered:
Players reported that [Transmute: Eternal Might] was also discoverable using Northrend Alchemy Research in beta. In live, despite some scattered forum reports of Alchemists learning this item (especially during the first week after Wrath launched), no credible screenshots have been produced, and many months have gone by during which most Alchemists have not discovered this recipe. Since no other recipes require this item, it is safe to assume that this recipe does not currently exist in the game.
Quest rewards
One transmute is rewarded from completing a quest:
The following five recipes are BoP and attainable from specific mobs in Icecrown. (Note that similar Leatherworking and Enchanting recipes drop from the same mobs.)