And then I remembered an article by Harold McGee that I'd read earlier in the week, about reducing mold on berries via thermotherapy and decided to try giving them a 30-second bath in 125°F water.
Wow. Seriously wow. Today is Monday and the berries look fine. They don't have that glossy, never-been-refrigerated look they did when I first brought them home, but they're just fine for shortcake or making more jam. And not covered with grey fuzz, which is how they'd be at this point normally.