Thanks to Virginia Postrel for sighting this important innovation story!

It’s Growing on Us by Candy Sagon in the Washington Post:

Spinach’s popularity nationwide began creeping upward in the ’80s, with the popularity of salad bars and pre-washed bags of lettuce.

But what really made the difference, say Bezart and others in the industry, was the technology to wash and pack fresh spinach without damaging the easily bruised leaves. Pre-washed spinach was a boon to busy cooks who didn’t like the hassle of rinsing the dirt and grit from fresh spinach, but flat-leaf and baby spinach, in particular, needed gentle washing and quick cooling so they didn’t turn slimy by the time they reached consumers.

"When the wash line improved, spinach improved," Bezart says.