they don’t taste the same, which was kind of a surprise. The Oreo cookie is a little more bitter than the Hydrox. What’s more, it tastes less like chocolate (to us that is) than the Hydrox cookie. This though, may be a very personal perception, as we discussed before when discussing why an Oreo cookie is black as well as when discussing the types of cocoa powders. If you’re used to a different type of chocolate or cocoa powder, you might find an Oreo taste more like chocolate instead of the Hydrox!
Apart from the cookie flavor, the filling of a Hydrox cookie is slightly different. The filling seems somewhat sweeter, but the overall balance for me is better in a Hydrox than in an Oreo cookie, it’s less sweet overall. Also, the crunchiness of a Hydrox is somewhat better than that of an Oreo. Even though differences are small, they clearly taste very different in a blind test. When reading the ingredient list of the two cookies it might seem that the Hydrox cookie contains more sugar, since it’s first ingredient is sugar. However, an Oreo contains both sugar and corn syrup, which is why the overall sugar content (as you can find in the nutritional information on the labels) is higher (14g in an Oreo vs. 12g). The ingredient list apart from this is actually very very similar. They contain almost identical ingredients in almost the same order. Which makes sense, since they look and taste very similar, the difference is nuanced.
https://foodcrumbles.com/hydrox-vs-oreo-cookies/