Should I Use Butter or Mayo on the Outside of My Grilled Cheese?

But there are many out there who are at war over one simple element of the grilled cheese sandwich: What do you coat the outside of your bread with? Butter or mayonnaise?

Both are mostly fat (which allows the bread to brown and crisp nicely), but unlike butter, mayonnaise is inherently spreadable when it’s cold, so you don’t have to wait for it to soften. Score one for the mayo-lovers. But how does it behave in the pan?

To find out, the Cook’s Country test cooks did a randomized tasting of grilled cheese sandwiches made with butter spread on the outside versus sandwiches made with a similar amount of mayonnaise; for good measure, they made another batch with extra-virgin olive oil.

While all three fats produced nicely browned, crispy sandwiches, the sample made with the EVOO tasted too strongly of the oil. Unsurprisingly, the sandwiches made with butter tasted deliciously buttery, while the sample made with mayonnaise tasted a little tangy (most likely due to the fact that the majority of jarred mayo has lemon juice or another acid added). 

The upshot? If you like the tang and convenience of readily spreadable mayo, go for it! If you are a butter purist, stick with butter. But anyone who was grilling their sandwiches in olive oil . . . please stop doing that. Also: Who are you?

There is one word of warning, though: Light mayonnaise won’t work as well here. Because a low-fat product has about one-third of the fat of regular mayonnaise (water is the first ingredient), it makes for a sandwich with spotty browning.