Wash the strawberries and cut the green tops off (see the notes section below for how to use these!)
Cut larger strawberries in halves or quarters and add to a medium bowl or large, clean jar.
Crush the berries just a little using a muddler or a fork and pour the sugar over.
Mix the strawberries and sugar together then cover the bowl with a clean kitchen towel (tea towel) and leave to soak at room temperature for 2 - 5 days (see note 1 below). Stir the mix several times each day to help dissolve as much of the sugar as possible and initiate fermentation.
When the syrup tastes mildly tart (days 2 to 5), pour the mixture through a fine mesh strainer or nut milk bag and catch the liquid in a bowl (this is the shrub mixture you’ll use as a base for drinks).
Gently press on the strawberries with a spatula to get out as much liquid as possible. Avoid pushing through any fruit pulp, as it’s just the liquid that’s needed. Either keep the strawberries to have with yoghurt or discard them.
Measure out the strawberry liquid and add an equal amount of vinegar to it then pour the finished shrub into a big glass bottle and store in the fridge for several months.
To enjoy, pour a little of the shrub into a tall glass with some ice and chopped extra strawberries then top with plain or bubbly water. It can also be used to add plenty of flavour to sauces, marinades and salad dressings.