Wash the jars and lids and place them on a dry towel.
Wash the cucumbers and cut the tails. With a large needle or a toothpick, the cucumbers are pricked from place to place (I do this procedure to get the brine into them well).
We take the jars and put vinegar to the bottom line of the jar, then for each liter we put a tablespoon of salt (if the jar has 1.7 ml we will put 2 tablespoons of salt, in the 4 liter jar we will put 5 tablespoons) and 3 tablespoons of sugar to each tablespoon of salt (if we put 5 tablespoons of salt we will put 15 tablespoons of sugar). Place dill, mustard and peppercorns in each jar and line up the cucumbers. When we have placed the cucumbers well, we fill them with water up to the top, we screw the lids well and we put them in a bain-marie in a bowl with water (the jar must be in the water until close to the lid) we let them boil until they change color from green dark green. If we want the cucumbers to be crispy, they should not be left to boil for a long time, as they will soften, not more than 20-30 minutes.
Leave in the water in which they boiled until they cool. Care must be taken to pull the lid well, to form a vacuum. If they didn't make a vacuum, it means that I didn't boil them enough or the lids weren't good.