Make two cuts in each lemon so that the quarters created remain attached. Stuff kosher salt into the crevices of the lemons. Then, place salted lemons tightly into the glass jar. If I have one or two leftover lemons, I’ll often squeeze the juice into the jar before closing it. But you don’t have to. This just gives the lemons a little bit of a head start.
Place the jar on a counter top, and then just watch and wait. Over the next few days, more and more juice will exude from the lemons, filling the jar. You can give it a shake now and then — or not — to keep the salt blended well in the liquid. In about three weeks, the lemons will get very soft, and the brining liquid thick and cloudy. Once that happens, you can store the jar in the refrigerator. As long as the brine covers the lemons, they’ll keep for about a year refrigerated.
To use, pick a lemon or part of one out of the jar with a clean fork. Give the lemon a quick rinse. Remove any seeds. Then, use the peel however you like — chopped or sliced in thin slivers. Some people discard the flesh, but Morse considers that wasteful. I always add some of the chopped flesh in with the rind in whatever I’m making.