1. Wash lemons and pat dry with a paper towel. 
2. Using a knife, trim ¼ inch from each end of 4 lemons, reserving the other 2 for Step 10. 
3. Stand the lemon up on one end and, using a paring knife, cut the lemon in half, stopping just before cutting all the way through. Turn the lemon and make another cut (as if cutting it into quarters), again stopping the cut before you are all the way through. 
4. Repeat for all of the lemons. 
5. Remove the seeds. 
6. Place the lemons in a medium bowl and sprinkle with ½ cup salt. Rub the salt into the inside and outside surfaces of the lemons. Add more salt as needed to cover all of the surfaces liberally. 
7. Remove and discard any other seeds remaining.
8. Transfer the salted lemons and the salt to a clean one-quart glass jar. 
9. Using a tamper, a wooden spoon, or your clean hands, press the lemons firmly into the jar so that the juice releases from the fruit and mixes with the salt to create a brine. Keep pressing until the fruit is submerged. 
10. Sprinkle 2 tablespoons of salt over the surface of the lemons, then add freshly squeezed lemon juice (from 1-2 remaining lemons) to the jar, submerging them in the brine. 
11. Add a pickling weight to the jar if you have one, or create a weight using a clean sandwich-size zip-top bag filled with water. To create a weight, fill the bag with about 1 cup of water and press out as much air as possible before sealing. 
12. Slip the bag into the jar and jiggle it a few times so that the bag’s surface covers the submerged lemon. 
13. Place a lid very loosely on the jar. 
14. Place the jar on the countertop at room temperature out of direct sunlight for 21 days. If the lemons are not under the brine at any time, remove the weight and press the lemons back down using a wooden spoon and clean hands. 
15. Rinse the bag with cold water and return it to the jar. 
16. After 21 days, remove the weight and screw a lid onto the jar. 
17. Store in the refrigerator for up to 12 months. 

To serve the lemons:

1. Remove a piece of preserved lemon peel from the jar. With your fingers, pull away the lemon flesh to expose the rind (the white pith and yellow peel) and discard*. 
2. Rinse the rind under cold water to remove the brine and some of the saltiness. 
3. Slice, chop, or mince the lemon rind before adding it to salads, tagines, soups, or stews. Preserved lemons also make a great addition to charcuterie boards.