Grapefruit sparkling water, three ways
The unsweetened infusion, the syrup, and the ratio that makes the finished drink.
In season: December to May. Ruby Red and Rio Star are the sweet ones. White grapefruit runs more bitter and belongs in syrup rather than in a glass of water.
Advertisement
Infused, unsweetened
Use
1 grapefruit, supremed into segments with every trace of peel and membrane removed, per 1 litre
Method
Cut the top and bottom off, stand it upright, and slice the peel and pith away following the curve. Then cut the segments free of the membranes over the jar so the juice goes in too. Any white you leave behind is bitterness on a timer. Cold still water, refrigerate.
Time
3 hours. 6 at the absolute outside. Grapefruit turns faster than any other citrus.
Sparkling
Still water for the steep, then top with sparkling. Grapefruit segments break down and shed pulp, and pulp strips carbonation within minutes.
Keeps
24 hours refrigerated with the fruit pulled at 6. Grapefruit keeps getting more bitter as it sits, even after straining.
The syrup
Ratio
1 cup sugar : 1 cup water : peel from 1 grapefruit in wide strips : 1 cup fresh grapefruit juice
Method
Dissolve the sugar in the water over low heat. Off the heat, add the peel strips and steep 15 minutes only, then strain them out. Cool, then stir in the juice.
Keeps
10 days refrigerated. Grapefruit juice goes metallic in the fridge faster than other citrus, so make small batches.
Note
Pull the peel at 15 minutes even when it smells like it could take longer. Grapefruit peel carries naringin, which is the bitter compound in the fruit, and it keeps extracting long after the aroma has finished arriving.
The finished soda
1 part syrup to 4 parts sparkling water over ice, salted rim optional
A pinch of salt in the glass suppresses bitterness directly on the tongue. It is the reason a salted paloma tastes rounder than an unsalted one.
The shrub version
1 cup grapefruit segments crushed with 1 cup sugar, refrigerated 24 hours, strained, then stirred into 3/4 cup white wine vinegar. Rest 1 week. Grapefruit makes one of the better citrus shrubs because the bitterness and the vinegar sharpness sit on top of each other instead of fighting.
What doesn't work: Half a grapefruit dropped into a pitcher with the peel on is undrinkable by morning. Grapefruit pith is the thickest of any common citrus and it is loaded with naringin. The second failure is reducing grapefruit juice on the stove to concentrate it. The sugars caramelise before enough water leaves, and you end up with a syrup that tastes burnt and is still bitter.
Goes with: RosemaryThymeJalapenoPomegranateMint