Squeeze enough from lemons to measure at least 1 cup (you should need 9 or 10 of the lemons). Discard the juiced lemons.
Remove stems from 5 of the remaining lemons. In a large pot cook the 5 whole lemons in enough boiling water to cover for 1 minute. Using tongs, remove lemons from water. Rub lemons dry with paper towels.
Cutting from the blossom ends to within 1/2-inch of the stem ends, cut each lemon into quarters (keep the quarters attached). Spoon about 2 Tbsp. of the salt into the center of each lemon. Press quarters together to reassemble whole lemons. In a sterilized 1-qt. canning jar or other jar, firmly pack salted lemons, pressing down to make lemons release some of their juices. Sprinkle any remaining salt over lemons in jar. Pour enough of the lemon juice into jar to cover lemons.
Cover tightly and chill at least 3 weeks before serving, shaking jar once a day until salt is dissolved. Press down on lemons as necessary to keep them completely covered with juice. Store in the refrigerator up to 6 months.
To use, remove lemon(s) from jar. Rinse lemon(s) with cool water. Remove and discard lemon pulp and any white portions from peel. Chop lemon peel; use in recipes as desired.