Can’t quite capture what was just right about that sandwich you had at that one place, that one time? Turns out it may be less about quality cuisine and more about the basic components of science and biology. ScienceFocus.com explains how to achieve a perfect panini using your brain instead of your stomach.

First, don’t skimp on the quality of bread. The cheap stuff won’t cut the mustard. Crisp, crusty bread “with a soft crumb,  like a baguette” is the ideal foundation for the perfect sandwich. “Our brain is designed to recognise contrast,” says Hervé This, said to be father of molecular gastronomy. “A great recipe capitalises on the way our brain and sensory organs perceive taste. Take the smell of tobacco, for example – over time our brain becomes fatigued to that particular sensory input and we stop noticing the smell. The same principle applies with taste.”

Toasting the bread gives it an advantage as well. Why is a grilled cheese so much more fulfilling than a plain cheese sandwich? Heat! “Heat excites essential oils in the ingredients, carrying most of the flavour into the air, meaning you’ll taste more via your nasal canals.”

A thin layer of margarine or butter bread isn’t just a matter of taste, it actually creates a “hydrophobic barrier” that will stop it from soaking up moisture. It’s this technique that stops most boxed sandwiches sitting on supermarket shelves from going soggy. Moisture from a sauce, spread or relish is imperative though, as it helps to carry the flavor compounds via your saliva to your papillae – the taste centers of your mouth.

Hervé also explains that sating your hunger isn’t just about the volume of food. It’s also the amount of time that you spend eating. “The more you have to chew on in each bite, and the more flavour you get with each mouthful, the less you need to eat to feel satisfied.” This is where the green stuff comes in: adding some fresh herbs or leafage ups the chew count per mouthful, improving the munching experience. Adding leaves and other interesting textures create obstacles that you’ve got to chew through. Literally,  just adding a few lettuce leaves “can vastly improve your sandwich satisfaction.”

Layering it right, now that you have the foundation in place, is the next key. Stinky cheeses or funky fish need to stay in the lower half of the sandwich to be most appealing to sensitive sniffers. According to researchers from the National Institute for Agricultural Research, taste testers unanimously preferred sandwiches when strong-smelling ingredients like smoked salmon or strong cheese were placed at the bottom, beneath any other fillers or salads, “The upper layers prevented the strong odours from entering the nasal passages at the roof of the mouth, which would have tainted the flavour.” But if it’s the best BLT ever that you’re after, don’t be fooled by the allure of the pork’s perfume. Dr. Graham Clayton at the Department of Food Science at Leeds University has determined that “it’s not the smell of bacon that’s most important, it’s the texture.” What’s your most scientific tip for making a heaped hero sandwich really super? —Casandra Armour