Could Raw Onions Be Your Ticket To More Tender Steak?

The perfect bite of steak relies on many characteristics from the cut to the seasoning to the cook, but right at the top of that list is tenderness. No matter how deliciously seasoned or perfectly cooked a steak may be, if it chews like an old tire, it isn't going to be a pleasant dining experience. Chefs and home cooks alike are always exploring the best ways to tenderize steak. Occasionally, a certain enzyme present in onions catches the culinary eye as a potential secret weapon for softening that sirloin — but does it do the trick?

To help us understand how these enzymes might aid in the tenderization of steak, we spoke with Benjamin Prelvukaj, owner of Benjamin Steakhouse, which is hosting the Champions by Benjamin Steakhouse restaurant for the seventh year at the 2026 US Open, available for fans onsite during the event from August 23 through September 13. As Prelvukaj explains, "Proteolytic enzymes are enzymes that help break down proteins. In meat, they can break down some of the proteins that contribute to the structure of the muscle, which can help make the meat more tender."

These proteolytic enzymes, or proteases, are present in all sorts of different ingredients, from pineapple and papaya to, yes, onions, but there are also endogenous proteases already present in raw beef itself. While the presence of these proteases in onions could help to tenderize meat, the levels are generally considered to be low compared to some other plant-based sources, and the effectiveness depends on direct contact with the meat. Plus, the proteolytic enzymes already in the meat can do the job just fine on their own.

"Over time, naturally occurring enzymes in the beef help break down muscle proteins, contributing to the tender texture and flavor of our dry-aged steaks," Prelvukaj notes. Dry ageing a steak is not a quick process, but it is a surefire way to increase tenderness and develop deeper flavors. If there isn't time to let the already present enzymes do their work — or if you don't have access to a butcher that can do it for you — adding protease-containing ingredients to a tenderizing steak marinade can help to somewhat speed up the softening of a tougher cut of beef.

That said, onions may be common in marinades, but that isn't because of their slight tenderizing properties. "While raw onions may have a mild effect on meat proteins, their tenderizing impact on our steaks would be minimal," Prelvukaj adds. Benjamin Steakhouse dry ages its meat already, so any allium used is not going to affect its tenderness much at all. "For us," he continues, "onions are more about enhancing flavor and complementing the natural richness of the dry-aged beef."

Therein lies the better reason to add a bit of raw onion to your marinade. These alliums are undoubtedly one of the ingredients that can seriously elevate your steak game, but that has much more to do with flavor than anything else. While those onion enzymes could make a slight difference in the overall tenderness, if that's the main concern, you're probably better off simply buying a nicer cut to begin with.