Put the orange juice with 100 ml tequila and the preserving sugar in a large saucepan. Bring to the boil and simmer for 4 minutes or according to the instructions on the package. Then add the rest of the tequila.
In the meantime, pour approx. 1/2 cm of the grenadine syrup into prepared glasses.
After a successful jelly test, the jam can be carefully poured into the jars in such a way that the grenadine syrup is not whirled up completely, but only bonds a little with the jam. The best way to do this is to let the jam run over the back of a spoon into the glass when pouring it.
DO NOT turn the jars upside down after closing, otherwise all the effort with carefully filling them was in vain.