*I personally don’t roast my peanuts. I buy my peanuts already roasted from Whole Foods. There is a lot of information on the web about the safety of raw peanuts. It is a bit of a controversial issue. As a safety precaution, and so I don’t have to worry about properly cooking them, I prefer to buy already roasted peanuts. As an experiment, to try dark roasted peanut butter, I re-roasted the already roasted peanuts that I bought at 350F until they got deep brown (about 10-15 minutes). Turns out, I prefer light roasted.
If you under-salt, you can always add more at any time. Just shake some over the top and mix it in with a knife. This works with any and all toppings, just mix em' in! I chopped some peanuts by hand and added them to the puréed peanuts to make chunky butter.
We leave the peanut butter out on the counter and finish each batch within several days. If you need to store it for longer, I would suggest refrigerating it. I don't know precisely how long ground peanuts will stay good. We always eat the peanut butter immediately, so I don't know what the shelf life would be...probably no different than the store-bought plain (no additives) peanut butter varieties.