Take one profound dish, pour 1l water and the lemon acid. Then, wash the quinces and peel one quince. Next, cut the quince on small cubes and put the pieces into the water (Repeat the procedure with the rest of the quinces. Is important to do it quick). After that, into a huge pot pour the water with quinces. Then, put the pot on the oven. Leave it in order to start boiling. When it does, cook it for about 5 minutes. After that, take the pot off  the oven.

On the other hand, start making sorbet. Into a huge pot put the sugar and 350ml. water. Then, put the pot on the oven. Wait to start boiling. Then, leave it to boil for about 10 minutes. After that, take the pot off the oven. Next, separate the quinces and the water(do not throw the water, use it as a juice) and add the quinces into the sorbet. The pot with the sorbet put on the oven again and leave it to start boiling. Leave it boiling for about 15 to 20 minutes.

In meanwhile, take the jars wash them and dry them. Then, warm them(preheat the oven on 50C degrees and put the jars).

Take the pot with quinces off the oven. Then, take one jar and pour quinces and sorbet in. Also, take the lemon and cut it on small pieces. Put 3 pieces into the jar. Then, close the jar. Repeat this procedure till finish all quinces. After that, leave the jars aside and cover them with small blanket. Leave it for about one day to cool down.