From here: http://www.foodnetwork.com/recipes/alton-brown/homemade-peanut-butter-recipe/index.html
Ingredients
15 ounces shelled and skinned AB's roasted peanuts, recipe follows
**1 teaspoon kosher salt**
1 1/2 teaspoons honey
1 1/2 tablespoons peanut oil
Alton Brown just generally prefers kosher salt, for reasons that don't really apply to peanut butter, which will be ground down anyway.
What matters is the total weight of salt. Remember, kosher salt tends to weight approximately 1/2 as much (depending on brand) as table salt, per unit of volume.
So you can replace the kosher salt with sea salt, or any locally available salt on a weight per weight basis. The absolute amount of salt to use is also completely a matter of taste and preference.
The purpose of the salt in peanut butter is only to enhance the flavor. It does not participate in any chemistry, and is not sufficiently concentrated to have any preservative effect.
The best peanut butter, in my subjective opinion, contains peanuts and nothing else. Liquidize the nuts in a food processor until it's as smooth as you want it; and you're done.
Peanut butter made this way might go a bit stiff if you leave it, but give it a good stir and it'll go back to normal.
Good wholefood brands sell ready-made peanut butter of this kind, with only peanuts on the ingredients list.
In your recipe:
If you like those flavours, then by all means add salt and honey.
Kosher salt comes in flakes or large grains. If you add it late, or don't process the mixture for long, then there will be grains of salt in the mixture; you may like this. I'm fairly sure that since peanuts are oily, not watery, it's possible for grains of salt to remain in there a long time without dissolving.
If you use table salt -- or if you use kosher salt and process for a long time -- the salt will fully dissolve and its flavour will be evenly spread through the mixture.
Salt is salt if dissolved into a liquid or blended into a paste.
Kosher salt is just larger crystals, it tastes and works the same as any other salt. It is mostly called for because it has become "fashionable".
Kosher salt does have specific culinary uses, but not as a dissolved or blended ingredient.
There is no global standard on table or kosher salt crystal sizes.
As with most recipes that do not specify a weight, use your better judgement on the amount of salt you require. You can always add more latter. Obviously the larger the crystals the less weight per volume there will be.
Also salt that is dissolved or blended tastes stronger than table salt sprinkled on top. Unrelated hint: if you want stronger table salt, grind it a little finer.
