Rhubarb water kefir

Anyone with a rhubarb crown on the allotment or at the end of the garden knows the feeling: from April to the end of June the stalks keep coming, faster than anyone can make crumble. Raw, rhubarb is fiercely sour. Cooked briefly with a little sugar, it becomes a soft pink syrup with a fresh, almost strawberry-like flavour. Add that syrup to the second fermentation of your water kefir and you have a drink with a colour and a tang of its own.

Which rhubarb to choose

For a proper pink colour, pick stalks that are red right through. Early in the year, the slim, bright pink forced rhubarb from Yorkshire gives the prettiest colour of all and a gentler flavour; garden rhubarb from April onwards is sharper. Green rhubarb tastes just as good, but your drink will come out pale yellow rather than pink. Choose firm stalks that snap when you bend them; limp ones are old and have less flavour. Use only the stalks: the leaves belong on the compost heap, never in the pot.

Let the syrup cool completely before it goes into the bottle. Hot syrup slows the kefir right down and the fizz stays away. You can make it a day ahead and keep it in a closed jar in the fridge.

What to do with the compote

From 300 g of rhubarb you are left with a good bowl of soft, sharp compote. Add a spoon of sugar to taste and serve it with custard, spoon it over yoghurt or a bowl of strained kefir cheese, or stir it through your morning kefir overnight oats. It also makes a lovely ripple in kefir ice cream, and freezes well in small pots, ready for the water kefir ice lollies: 150 g of compote is enough for a batch of eight.

The base: water kefir from the first fermentation

You start with an ordinary batch: 30 g water kefir grains, 4 tablespoons sugar (about 60 g), 1 litre water, 1 dried fig and 1 slice of lemon, 24 hours at 20 to 25°C. Everything about that first step is in How to make water kefir. The syrup only goes in at the second stage, in the closed bottle, so your grains stay clean and strong. With 60 g of grains you can run 2 litres a day and keep a bottle in the fridge for the whole rhubarb season.

Variations

• Rhubarb and strawberry: cook 200 g rhubarb with 100 g strawberries. A classic pair, and the colour turns deep pink. See also the strawberry water kefir.
• Rhubarb and ginger: simmer three slices of fresh ginger in the syrup for a warm undertone.
• Rhubarb and vanilla: half a vanilla pod in the pot gives a soft, round flavour.
• Rhubarb and elderflower: in June, a flower head in the bottle, as in the elderflower water kefir.
• Rhubarb and orange: grate a little orange zest into the syrup.

Frequently asked questions

All the recipes and guides are on the water kefir page, and our live water kefir grains give you a fresh litre every day.