How safe is it to leave food unrefrigerated?

Food safety may not be fun or sexy, but we all do eat (some more than others) after all.  So the topic is about self-preservation, not to mention how embarrassing it is if you sicken your best friend or the co-worker you invited to dinner.  Following sensible food safety practices can mean the difference between enjoying memories of a good meal and going to the emergency room.  How do you know if your methods are safe?  Sometimes even if you’re an expert cook, you may not know (or appreciate) the potential consequences of your own tried-and-true methods.

One of my favorite food writers is Michael Ruhlman.  Among his many accomplishments, Michael has championed the idea that you don’t always need a recipe if you know the right ratio of ingredients for a dish.  Among his books are “Ratio” and “The Elements of Cooking.”  He is a sensible cook and someone I look to for practical advice.  Another of my favorites is Harold McGee, a food chemist and the author of several great books, including “Keys to Good Cooking: A Guide to Making the Best of Food and Recipes.”

This week Harold McGee wrote a fascinating and important piece on the food safety issues that arise if you leave soup, broth or meat stock unrefrigerated.  His piece was inspired by Michael Ruhlman’s practice of leaving chicken stock at room temperature for days as he uses it for various purposes in dishes during the week, re-boiling it before adding it to another dish.  McGee investigated whether this practice is safe, while recounting his own practice of leaving meat stock made at night in a covered pot until morning, then re-ehating, straining and cooling it, before refrigerating the stock the next morning. 

McGee asked O. Peter Snyder, a Ph.D. food scientist and consultant who has been critical of overly cautious government food safety regulations, whether his own practice and Ruhlman’s are safe.  Dr. Snyder said leaving chicken stock on the stove for days is “very high risk” because if the stock is not re-boiled for long enough it could sicken or kill someone.  He thought that McGee’s soup was OK as long as it went in the refrigerator within a few hours of cooling to 135 degrees. 

It’s well worth your time to read both McGee’s New York Times article and a subsequent clarification blogpost from Ruhlman.  If you don’t have the time to do that now, come back to them soon – you won’t be sorry. 

The moral of this story?  Stay on the safe side.  Ruhlman is an expert cook and boils his soup thoroughly and long enough before using it.  But if one adopts his technique and skimps on the last step (re-boiling) the results could be disastrous.  

Harold McGee’s simple explanation for how to prepare and store food safely works for me:

My own everyday approach to safety is to try to keep cooked foods either hot or cold until I’m ready to serve them, get leftovers in the fridge during the pause before dessert or soon after, and reheat leftovers that need it until they’re boiling or steaming. 

Enjoy the weekend – and stay safe!