Are Costco's Oreos Actually Different?

If you've ever tested fountain soda against the same canned product, you know it tastes different. And when it comes to our favorite sandwich cookie, Oreos, tasters swear there's a difference between the Costco package and other kinds. Say one Redditor, "I had my Costco cookie submerged in milk for close to a minute and it was still crunchy! Does anyone know why that is? The overall taste is similar, I guess the texture is different. Even dry they don't taste the same as [non-bulk] Oreos." 

Another Redditor echoed that idea in a different thread: "I'm eating a sleeve of Costco [Oreos] right now and they taste... Different comparing them to every other [Oreo]. Has anyone else noticed this? Is it because the bulk batches have different ingredients?" But others have noted changes in standard packages: "I just bought a standard package of [Oreos] from Walmart after not having them for 6 months or so and they were what you are describing. The cookie part was overly crisp and light had a much different taste, and did not take on milk when dunked." Is there any real difference between Costco Oreos and the rest?

These tasters might have some very discerning palettes. There actually IS a difference between the classic Oreo pack and the Costco one. To be specific, there are exactly two differences that we could find. One is that classic Oreos list artificial flavor among the ingredients (via Shop Oreo) while Costco's version lists natural flavor (via Costco). Moreover, the classic Oreo uses high fructose corn syrup whereas Costco's cookies are sweetened with invert sugar. Invert sugar is a mixture of glucose and fructose known for retaining moisture, reducing crystallization, and producing a smoother mouthfeel (via Science of Cooking). High fructose corn syrup has a different glucose-to-fructose ratio.

We can't seem to find any official statement on this, but the proof is on the package. Quora users share that this isn't the first time Oreo has made a tweak on the sly, noting that high fructose corn syrup itself didn't exist when the cookie brand first debuted in 1912. Other users have pointed out removals of both lard and trans fats, and ingredient listing would seem to confirm neither of these is in the cookie itself. No matter how you shake it, though, Oreo cookies are a nostalgia-filled indulgence for many. 

And this subtle difference between types is the best excuse we've had to taste with a glass of milk in quite a while.