Almost every single member of my immediate and extended family has a birthday in March or April. For us, it is a time of gifting, celebrating and eating cake! It seemed like a great time to shed some light on a that question I get often:
Can I leave cakes or pastries made with buttercream frosting at room temperature for extended periods of time? Will the frosting spoil?
Butter is made from milk, which we know must be kept refrigerated to ensure safety. So, why do so many people leave their butter (and uncooked, butter-based products like frosting) out on the countertop? Is this practice safe?
Though butter is made with milk, it consists of 20% water (which is relatively low compared to other foods), and it generally contains salt. These two characteristics make butter a place where pathogens are unlikely to grow. Food-borne illness outbreaks associated with butter have not come to public attention recently. In the past, butter was made with unpasteurized milk, making food-borne illness outbreaks from butter more common, but since the milk in butter is now pasteurized, this is no longer a concern.
Storing butter
According to University of Missouri Extension, it is recommended that you store butter [or something made with butter like buttercream frosting] in the refrigerator, covered between meals. However, this source indicates that you do not need to worry “too much” about the safety of consuming butter that has not been refrigerated. Refrigerating your butter and butter-based products, however, will virtually assure safety. The main reason to refrigerate your butter is to extend its shelf life and prevent rancidity.
And, remember that because of its high fat content, butter is highly caloric so consume it in moderation!
Source: http://missourifamilies.org/quick/foodsafetyqa/qafs649.htm
Author: Joanna Rini, Family and Consumer Sciences Educator, Ohio State University Extension
Reviewed by: Linnette Goard, Field Specialist, Food Safety, Selection and Management, Family and Consumer Sciences, Ohio State University Extension.