Alchemy allows you to turn your collection of herbs, wild mushrooms, crystals, and monster limbs into Potions, Elixirs, Grenades, and Coatings.
It takes three of the same Alchemical Ingredient to create an Alchemical Extract; either a Sublimate, Salt, Essence, Ash, Vitriol, or Suspension. Recipes (Alchemical Solutions) call for a specific Extract (e.g. Salts of Mugwort) in addition to a generic one (e.g. any Suspension). Each Ingredient converts into only one type of Extract, so there is no danger in using the "Extract All Ingredients" button.
You should choose which Extract you use in the generic slot carefully, however, as you may need it as a specific component in a different recipe. Since you cannot swap out the auto-filled Extract in the generic slot, the player might find it helpful to store Extracts in the Camp Stash and only add them to their inventory as desired for a specific recipe.