After checking a couple of sources, we have found a general ratio of 2 to 2-1/2 ounces of salt (3 scant tablespoons) per quart of water, or 60 grams per liter.

The general process is to wash the peanuts thoroughly in their shells. Place them in a pan and cover with the medium brine. If you're a flashy sort of person, you may choose to add 2 to 4 star anise. Cover and boil for 45 minutes or until the nuts are tender. Turn off the heat.

Now the burden falls squarely on you. Take out a nut, break it open, cool it enough to taste, and see if it has reached your desired level of saltiness. Leave the nuts in the brine if you want them saltier; drain them as soon as they are salty enough. Once they are cool enough, you can shell and eat them, or you can store them in refrigerator for as long as five days.