If you have ever read or watched America's Test Kitchen, you have seen surprising results of blind test tests. The most famous one is imitation vanilla vs real vanilla extract.
What other categories do you think there would be surprising results?
I have a couple.
Salts where table salt, sea salt, kosher salt and iodized salt on food is compared.
Chicken stocks with and without carrots and celery.
Store brand vanilla ice creams.
Different varieties of ground black pepper.