Q. Is it true that butter will stay fresh on the counter?
A. While salted butter can be left out longer than other varieties, leaving butter at room temperature isn’t always safe. The salt content and fine water dispersion in regular salted butter inhibits the growth of almost all harmful bacteria. But when that balance is changed — in unsalted, light, or whipped butter, for example — the risk of contamination is greater. In fact, there have been outbreaks of staphylococcus aureus food poisoning associated with whipped butter left at room temperature. Other bacteria, including listeria, can also grow in low-salt or unsalted butter. Butter can be contaminated at any point after the cream is pasteurized — during processing, shipping, or even in your own kitchen.