Step 1

Cut the lemons into quarters the long way, then add salt, mix, and quickly seal in the vacuum bag. Allow the lemons to ferment in the bag for 2 weeks, or until sour to your liking.

Step 2

As the fermentation progresses, the bag will inflate from carbon dioxide. While I've never had a bag burst, I do cut the corner off of the bag as needed to release carbon dioxide, resealing the cut corner without using the vacuum to keep the lemons contained.

Step 3

After the lemons are fermented, remove them from the bag, put them rind-side down on a cutting board, and, using a sharp paring knife, cut away the pith and seeds and discard. If you used the vacuum method, you can squeeze the capillaries and pith to extract fermented lemon juice.

Step 4

From here, the lemons are shelf stable and can be held in the refrigerator, or water-bath canned in their brine if you used brine. Canning in brine will also tenderize the rind, which is a nice bonus. Do not can lemons in their juice, which could become bitter-save that for another fresh purpose like salad dressing.

Step 5

Finally, you need to heat the rind long enough for it to become tender. My favorite way to do this is to seal in a vacuum bag and cook sous vide at 150 F for 2 hours, but you can also steam them.