The Potential Danger Of Reusing A Meat Marinade
So you've just put together your magnum opus as far as marinades go. You have used what you need for your meat, there is a bit left over, and it breaks your heart just thinking about throwing it away. Is it dangerous to reuse?
Typical homemade meat marinades consist of a flavor element (which can be anything from zesty to spicy to herby), a fat component which is usually an oil of some kind helping with the absorption of flavor, and an acidic element responsible for tenderizing the meat, per Chicken.ca.
With these ingredients, the marinade recipe itself has a lifespan of no less than a week, per Real Simple Good, and even longer depending on the ingredients of the marinade and how you're storing it. In the case of a producer-packaged version, the lifespan can be up to two years unopened (given that the storage methods are optimal), per Still Tasty. Whether it's homemade or store-bought, though, reusing the same marinade is not recommended.
Recycling meat marinade
Despite a marinade's propensity for a fair amount of longevity (per Still Tasty), once it comes into contact with raw meat, its usability declines dramatically. The marinade becomes too contaminated, which even acidic ingredients can't fix (via The Spruce Eats).
According to the New South Wales Food Authority, raw meat often contains bacteria like salmonella, Escherichia coli (E. coli), and the norovirus, among others. These bacteria are foodborne and responsible for food poisoning. While the bacteria on meat will die once the meat is cooked, per FoodSafety.gov, microorganisms remaining in the leftover marinade (which have come into contact with the raw meat) will not because the marinade — unlike the meat — has no exposure to heat.
Not all is not lost, though. By cooking the marinade to a temperature of 212 degrees Fahrenheit, the unwanted microorganisms die (via Kansas Department for Aging and Disability Services), and the marinade becomes safe to use once more.