Taste is incredibly complex. According to science, how something “tastes” is a combination of three sensory experiences: taste, smell, and touch. Scientists have also discovered that the stories we tell about a food—was it tasty, was it gross, was it familiar, or was it foreign, would I eat it again?—aren’t always consistent. Sometimes our social beliefs and feelings can play tricks on us. For example, our food preferences are affected by factors that food scientists call biases, such as the confirmation bias (where we give preference to evidence that supports what we already believe) or, as this food scientist explains, the courtesy bias.

When we combine all of the new tools in a food scientist’s toolkit, we realize how much we have still to learn about what taste means for our health and happiness. Our pre-existing beliefs, such as the belief that specific cuisine or ingredient is naturally bad, or naturally good—can have a real effect on our physical experience of eating. No wonder people have had different reactions to MSG, and opinions about whether it was enjoyable to safe to eat.

Scientists have recently learned that we have “taste” and “smell” receptors all through our bodies—in organ systems that seem to have nothing to do with eating, like our lungs and our spinal column—even our skin. This complexity in part explains why it took scientists decades to pinpoint how MSG worked in the body. Since the 1940s, researchers debated whether MSG conferred a unique basic taste, or whether it just amplified existing tastes.

At the turn of the twenty-first century, neurobiologists at the University of Miami found out how MSG worked. They identified specified molecular receptors for glutamate in the taste buds of a mouse: this gave us a scientific basis for including umami in the list of basic tastes. Watch this science journalist describe the history here. Glutamate isn’t the only thing that tastes umami. Umami receptors are activated by other ingredients found in foods, such as glutamate’s cousin amino acid aspartate, and compounds called ribonucleotides. These chemicals interact in a way that exponentially increases the umami we taste, and food scientists have been relying on these techniques for building deliciousness for decades. Find out more about this history at www.sarahetracy.com.