Ask Dr. Potato

Q&A: Potato Salad Safety

Q:

Could you tell me how long it is safe to keep potato salad out of the refrigerator and on a picnic table?  I have been told it is not the mayo or eggs that go bad but something to do with the starch in the potato...is that correct?

A:

Once a potato is cooked it should be kept in the safe zone for temperatures, remember hot food hot and cold food cold. That’s a tip I learned from my boss on day-one, when I started in the foodservice business, it was right up there with “get the money in the bank” as important things to do when running a restaurant. According to the 2005 FDA Food Code, the danger zone is defined as 41°F - 135°F (5°C - 57°C). Potentially hazardous food should not be stored at temperatures in this range in order to prevent food borne illness, and food that remains in this zone for more than four hours must be discarded. Ask yourself, how long would I keep raw eggs or mayonnaise out at room temperature or on a picnic table in 100 degree summertime weather?

Your friend is incorrect.  The potatoes have a fairly neutral PH (acid versus alkaline) so they allow the bad stuff to grow when unrefrigerated. My personal guideline is 1/2 hour, but I usually put potato salad out in a bowl lined with a larger bowl that has ice in it.  For transporting a potato salad to an event I have found that the blue ice containers (freezer packs) work well.  I put it right in the middle of the deepest part of the salad to make sure it stays chilled.  Chill a cooler and then put the salad container in that.  You can also break the quantity of potato salad up into a couple of bowls (what is washing an extra bowl versus someone getting sick?).

With all this negative talk, here is a positive idea for your next potato salad:

  • Baked Potato Salad - This uses traditional mayo, but is a baked potato salad.  Note it specifies chilling for a minimum of two hours before serving.