Stemming strawberries prior to washing soaks up water, diluting the fruit’s flavor.
It doesn’t matter if you stem the berries or not before washing them.
To determine if water is absorbed during washing, we weighed a carton of stemmed strawberries, then washed the berries using the test kitchen’s preferred method (in a colander under cold running water for 30 seconds, then gently spinning them dry in a salad spinner). We weighed the berries again and found they hadn’t absorbed a measurable amount of water.
The bottom line: Wash fresh strawberries by quickly rinsing them under cold running water and then spin dry.