The Taste of Success

Unlike hybrid onions (red, yellow and white) which have a pungent or hot taste, Keystone "Certified Sweet™" Onions have an incredibly sweet taste. The country’s only 100% certified sweet™ onion, Keystone "Certified Sweet™" Onions are America’s favorite. Last year, we sold over 100-million pounds – sales at the national retail level have grown over 20% annually. Bursting with flavor and now available year round, Keystone "Certified Sweet™" Onions are popular in soups, salads, salsas, sandwiches and all kinds of main dishes. One taste and it’s easy to see why.

        The Taste Test

It takes a few seconds to decide how sweet an onion is because the primary flavors we recognize in onions are not present until we chew the onion tissue. Then an enzyme in the tissue becomes mixed with certain flavor compounds that are transformed into other chemicals that give us the flavor sensations of heat and pungency. In some cases, these compounds may cause tears.

        The EDP Test

The flavor we call hot or pungent is due to specific sulfur-containing compounds and can be measured indirectly by determining a chemical by-product called pyruvate (pyruvic acid). By testing the amount of pyruvate released after crushing during a specific time period and under specific conditions – the Enzymatically Derived Pyruvate test (EDP) – we can determine if an onion is sweet or if it is hot. The EDP test gives Keystone the ability to analyze any onion to determine if it’s good enough to be a Keystone "Certified Sweet™" Onion. Consumers want a favorable taste experience and that’s what we work overtime to give them. Under our leadership, sweet onions are stringently grown with specific methods to assure low pungency levels and optimum brix (sugar levels).

        Setting the Standard

As an industry leader, Keystone is deeply concerned about consistency. We spend considerable time, energy and resources to ensure a consistent taste profile while retaining the uniqueness of the individual varieties and growing districts associated with sweet onions. We’re also working hard to promote high standards. Unfortunately, there are no official pungency standards for the sweet onion industry. Given this absence, Keystone is leading the industry by employing a certification program conducted by National Onion Labs,Inc. National Onion Labs,Inc's flavor certification program scientifically verifies that our onions will meet or exceed customer expectations. All Keystone "Certified Sweet™" Onions are 100% certified sweet or extra sweet and carry a certificate that verifies its rating.

        Loads of Customer Benefits

Consumers want Keystone "Certified Sweet™" Onions because they have a flavor that’s bold but not overwhelming. The high sugar content and less pungent flavor makes them very appealing. They also contain many health-promoting benefits and may guard against infections and chronic diseases, ward off colds and help relieve indigestion. Onions have been shown to help protect against cataracts, cardiovascular disease and cancer. They’ve also been linked to compounds that lower blood pressure and cholesterol. Fat free and cholesterol free, they’re a good source of dietary fiber and have very low amounts of sodium.