Stuff the thinly sliced radishes into glass jars or containers.
In a saucepan, combine the water, vinegars, sugar, salt, pepper, and garlic over medium heat. Bring to a simmer and stir until the sugar dissolves. Remove from heat, and pour this mixture evenly over the jars with the raw radishes.
Seal the jars and let them cool to room temperature for 30 minutes. Transfer the jars to the fridge and store for up to three weeks.
Notes
Sub red wine or apple cider vinegar if you don't have sherry or white wine vinegar.
Possible additions include a teaspoon of whole peppercorns and/or fennel, caraway, or coriander seeds. You can also add a pinch of red pepper flakes for a spicy kick.
The nutrition facts are for 1 jar (½ of the recipe) and include the full amounts of the vinegars. A few pickled radishes will not have the same nutrition facts.