The Reason It's Important To Keep Peanut Butter From Splitting
Oils can sometimes get a bad rap. So your instinct upon seeing a bunch of oil floating above the surface of your peanut butter jar may be to question if it's still safe to use your peanut butter.
But that oil is a good thing. Business Insider explains that peanut oil is released when the peanuts are ground. The oil helps make the peanut butter spreadable. But when left alone, it rises to the top of the jar. If there is no oil in a jar of peanut butter, though, that probably means your peanut butter has been adulterated with another substance, such as palm oil or rapeseed oil. You should really want to see that layer of oil if you don't want other additives in your peanut butter.
It's not as if the split between the oil and the butter is hard to rectify. It just requires a bit of mixing back together. However, Livestrong learned that there was an added nutritional benefit to stirring the oil back into the peanut butter as well. "The fat in any of the natural nut butter is healthy monounsaturated fat (MUFA)," Amy Kubal, a registered dietitian, told Livestrong. She then noted an association between people who introduced more MUFA into their diet and reduced risk of heart disease.
Still, there is another important reason to keep the oil mixed in with the peanut butter.
The oil keeps the peanut butter fresh
The oils in the jar aren't just essential for making peanut butter creamy and spreadable. When the peanut oil splits from the peanut butter, it actually reduces the shelf life of the peanut butter.
Food Crumbles writes the issue is that once the split occurs, the oil begins to oxidize. The oxidation will remain even when you mix the oil back into the butter. They do add, however, that the splitting doesn't harm the peanut butter itself. You can still eat it, provided that it still smells fresh enough.
As mentioned earlier, not all peanut butter splits. The National Peanut Board explains that many brands of peanut butter use hydrogenated fats to keep the oil from splitting from the butter. The result of this enforced unity is that the non-splitting peanut butter has a longer shelf life. Fully hydrogenated fats are different from, and preferred to, partially hydrogenated fats because they are not trans fats. But if your interest is in having a peanut butter made purely from peanuts, you will have to accept the splitting and the shorter shelf life.