Start with sterilizing the jar: either of two methods: 1. pour boiling hot water into the jar and let stand for a while and then drain without drying or 2. place the clean jar for 20-30 minutes in an oven pre-heated at 150 C and then cool down at room temperature
Wash the lemons and remove any untidy or brown spots
Cut the top part off and then make a cut down to about 1 inch from below. Then do this again perpendicular on the previous one. The lemon will have its 4 quarts still connected
Place 1 tbsp of salt on the flesh of each opened lemon. Do this over a small bowl, collect any juices and salt, which can be added to the jar at the end
Place each salted lemon in the jar and keep for several days at room temperature but in the closed jar. Press now and then the lemons, so they compress and more juice is released
After a week in the jar, compress the lemons again, if need be add a few new ones, pre-treated with salt in the same way. Add the juice of one or two lemons to ensure the lemons are covered by briny juice.
Add the olive oil on top and store in the refrigerator
After 4 weeks the lemon can be started to be consumed. Store longer for even better taste