First, put the grated ginger and ¾ of the lemon thyme in a bowl and sprinkle with sugar.
Wash three of the lemons, cut them in half and squeeze them.
Using a paring knife, cut off the outer 1-2 mm of the squeezed lemon peels so that there is not too much of the white part of the peel.
Add juice and peels to bowl. Crush coarsely with a mortar, especially crushing the thyme properly. Allow to steep for about 15 minutes.
Then strain through a fine sieve and squeeze the mixture firmly.
Infuse the juice with still or sparkling water to taste. Slice the 4th organic lemon and add to the finished lemonade.