If your fridge is too cold, you're wasting energy. Too warm, and you're likely wasting food... or running the risk of food poisoning.
"Life begins at 40" is the catchy phrase Marion Nestle uses to remember the temperature where bacteria start to grow exponentially. We've been trying to track down the exact temperature recommended, but it seems there's a range: thedailygreen reports the EPA suggests 37°. But the USDA suggests keeping the fridge at 40° or below. And a Fine Cooking article we read last month (the article is not online) said 39° or lower.
We trust Marion Nestle: if "life begins at 40," then we're going with 39°. At $4.50, this Taylor refrigerator thermometer should pay for itself in saved energy, less wasted food, and stomach trouble prevented.