Plum sparkling water, three ways
The unsweetened infusion, the syrup, and the ratio that makes the finished drink.
In season: August and September. Italian prune plums in early September are the best of them for syrup.
Advertisement
Infused, unsweetened
Use
3 ripe plums, quartered with the skins on, per 1 litre of water
Method
Plum flesh is bland and the flavour lives in the skin, so cold water pulls colour and tannin before it pulls plum. Quarter them, cover with cold still water, refrigerate, and expect a light drink.
Time
6 hours. Past 8 the skins hand over tannin and it goes dry and puckery at the back of the mouth.
Sparkling
Still water for the infusion. Plum is one where the sparkling top-up earns its keep, because bubbles carry a thin flavour better than flat water does.
Keeps
2 days refrigerated, fruit out at 8 hours
The syrup
Ratio
2 cups pitted and chopped plums with skins : 1 cup sugar : 1 cup water
Method
Simmer 15 minutes until the skins let go of their colour and the flesh falls apart, steep 30 minutes off the heat, strain without pressing.
Keeps
2 weeks refrigerated, 6 months frozen
Note
Plum is the stone fruit that improves with heat. Cooking turns the raw green edge into something closer to spiced jam.
The finished soda
1 part syrup to 4 parts sparkling water, over ice
One star anise pod or a single clove in the pan for the 30 minute steep.
The shrub version
2 cups chopped plums and 1 cup sugar, covered in the fridge 2 days, strain, stir in 3/4 cup red wine vinegar, rest 1 week.
What doesn't work: Peeling the plums first. People peel them out of habit from peaches, then wonder why the syrup came out beige and tastes like sugar water. The skin is where the plum is.
Goes with: Ginger