A quarter century ago, Steven Spielberg created velociraptors that were viscerally compelling enough to toe-claw tap dance straight into our nightmares. Last year, the VFX team behind Rogue One gave us a posthumously CGI-reanimated Peter Cushing as Grand Moff Tarkin, and that inspired a different and unintended kind of unease. Japanese roboticist Masahiro Mori’s famous Uncanny Valley hypothesis proposes that near-perfect human replicas elicit a specific form of revulsion—we’re simultaneously intrigued by something seemingly human enough to deserve empathy, and yet repulsed by the realization that something is off.

Now, we usually cut fake dinosaurs some slack because humanity's social code doesn't depend on interpreting T. rex eyebrow tics. But our finely calibrated facial lie detectors are critical when it comes to recognizing and assessing threats, rivals, allies, and potential mates. And, as it turns out, we have similar systems in place to monitor another intimate element of our survival: eating.

From birth, we are wired to seek sweetness and avoid bitterness, two points on an intricate flavor compass used by our ancestors to navigate between easy calories and potential poisons. We no longer lean heavily on flavor for life-and-death guidance, it's true. But those instinctual flavor-tracking systems continue to operate in the background of our daily lives, even as the food landscape changes dramatically. Fervent foodie tribes who demand low-sugar, grain-free, and especially animal-free alternatives to our favorite foods are pushing food industry innovation deeper into the realm of imitation. And as this pressure mounts, food companies should be wary of stumbling into the unsettling pit of another uncanny valley.

Creating food is an intricate balancing act of battling senses. Salt, for example, suppresses bitterness and enhances sweetness, while indole, a single aroma compound, can give us either the aroma of jasmine or barnyard feces, depending on its concentration. Our ears act like amplifiers to turn up the crunchy texture of potato chips, and our eyes gobble up tasteless yellow food coloring to boost the apparent fruitiness of canary-colored banana pudding. And even our memories and moods can warp and twist flavor perception. If I share a bite of what I think is perfectly cooked and seasoned barbecue brisket with a 65-year-old Japanese winemaker, I might hear that it was too soft, undersalted, and oversmoked.

So building food from the ground up to hit a rigidly specified flavor target, it should seem obvious, is nothing short of a cosmic achievement. Especially if you hope to scale that innovation to the level of commercial food production, as companies like Hampton Creek, Ripple, and Memphis Meats have attempted in the last few years.

Like the clunky claymation effects that predated Phantom Peter Cushing, the first commercial food analogues aimed slightly lower than sensory parity. Success for the first butter substitutes and tofu-based “deli meats” was defined primarily by whether the material could be spread on toast or stacked under lettuce and tomatoes. These first steps were far enough from the uncanny valley that they were an exciting novelty for health-conscious diners or vegetarians. For the rest of us, they were a blip on the radar.

But as consumers have gotten more discerning, the ambition and investment in imitations have grown. In the past half-decade, we’ve seen millions of dollars put towards developing sophisticated, animal-free renditions of dairy, meat, poultry, eggs, and seafood, transitioning the movement out of the test kitchen and into the mainstream. Hampton Creek is making strides to expand their egg-free empire beyond mayonnaise and into our morning breakfast routine with plant-based, scramble-able eggs. Memphis Meats looks to go straight to the source, culturing animal muscles in vitro to build chicken wings and beef steaks cell by cell. The food scientists leading this charge are armed with sensitive gas chromatographs to map the volatile composition of yogurt as it ferments, texture analyzers to quantify the snappiness of a sausage casing or the gooeyness of a perfectly poached egg, and massive, searchable libraries of taste and aroma compound descriptors to aid in the architecture of new flavors.

We can now translate real food reference points into data-based flavor blueprints with better resolution than ever before. But the data is still incomplete—miniscule quantities of aroma compounds that barely register on a gas chromatograph readout can scream into our nostrils, for instance—and that can leave us with some truly unnatural eating experiences.