Can Pizza Robots Be Engineered to Have a Human Touch?

In a brick-lined industrial building in Hawthorne, a bright-red canopy and an equally red truck sit outside the entrance to Stellar Pizza, a startup that hopes to introduce the first fully functional pizza robot to Southern California. The idea is simple: make pizzas to order in a fast, functionable, controllable way, spitting out gently charred and bubbling pies after four quick minutes.

Founded by former SpaceX engineers Benson Tsai, Brian Langone, and James Wahawisan, the fully mobile machine will soon roll around the streets in a truck, serving long-fermented dough pizza to order. Based on the early tests and tastings, this machine could very well change the way pizza is produced in the United States and — maybe — the world, but first, it’ll have to convince pizza-obsessed Americans that quality pizza doesn’t have to be made by human hands. And the opportunity could be immense for Stellar, with Americans eating upward of 3 billion pizzas a year and spending $46 billion annually on them.

In 2018, Pasadena tech startup Miso Robotics created a robot called Flippy, an automated arm meant to be installed inside fast-casual restaurants. First up was Caliburger down the street, where Flippy would show off its timing and tech to customers on the other side of the counter. The robot drew mild interest from the media and public with its ability to flip a burger patty, but it didn’t revolutionize the way burgers are made or eaten (it’s now marketed for frying things like fries and chicken). While the flipping of burgers is certainly a straightforward calculation, the rest of the dish is pretty complex from a mechanical standpoint. There are multiple components that require various stages of cooking or preparation, like the toasting of buns to the melting of cheese to the gentle placement of toppings — most of which Flippy can’t do yet.

Matthew Kang

The question of automating pizza seems more attainable, especially with the minds of 23 engineers who used to work together at SpaceX’s headquarters a few miles away and helped create the Stellar Pizza robot. Previously these engineers were tasked with putting reusable rockets into space (with the eventual goal of putting humans on Mars), or creating a new global satellite Internet system. Stellar also has former SpaceX culinary director Ted Cizma and dough consultant Noel Brohner of Slow Rise Pizza handling the actual recipes.

Making pizza is relatively contained, or a closed loop, in engineering speak; ingredients can be prepped for an assembly line, cooking takes place in the static heat of an oven, and packaging requires a square cardboard box. Despite its moniker of Stellar Pizza, the team, which has spent the better part of two years designing this robot, also seems interested in catering to human stomachs on earth.

I first arrived at Stellar Pizza for a tour of the robot, which fits on a pallet that can easily slide into the back of a catering truck. I placed an order on a simple app installed on a phone the Stellar Pizza team presented to me: a pepperoni and sausage pie, as well as a supreme pizza with olives, bell peppers, onions, pepperoni, and sausage to see how the robot would handle a fully loaded pie.

The machine looks nothing like Wall-E and its adorable mechanical body, but more like a Rube Goldberg apparatus. The most formidable visual component is a white refrigerator in the middle. Look at the far end, though, and you can see where the production process begins. A crane inside of a smaller fridge of trays gently and methodically picks up a ball of dough like a beefy toy machine claw, then flips it onto a mat that’s then swept under a metal press from a conveyor belt. The imprint of the claws adds four divots to the ball, but with a modicum of heat from the metal pressing down on the dough, it forms a circular pie with a cute, perfectly rounded one-inch cornicione. It’s hypnotic to watch its movement, but these dough presses are already common in the pizza industry, as anyone who’s been to Blaze Pizza has seen.

Stellar Pizza

Stellar Pizza

From there a belt slips the formed pizza crust into the lower portion of the big white refrigerator, where it receives a calculated daubing of tomato sauce and a swoosh of grated mozzarella. The next component is clever, and intentional, says test engineer Arik Jenkins (another SpaceX alum). Pepperoni is probably the most popular meat topping on pizza, with 64 percent of adults saying they like it, so inside Stellar’s machine there’s an array of 19 full pepperoni sausages, slicing rounds to order directly above the pie in one fell swoop. This is because pepperoni’s flat shape, which human fingers can place evenly onto a pizza, isn’t as simple to place for a machine. This horizontal guillotine isn’t just effective — it’s something to behold.

The rest of the toppings flow through tubes suspended over the next portion of the belt, dropping pre-cut ingredients, many of which fall over the side and end up in topping purgatory. While all these procedures are nothing new to the food industry, where massive companies have built machines to make everything from frozen orange chicken to fancy ice cream desserts, the Stellar engineering team had to design and build every part of this machine to fit within the confines of a mobile truck.

The final cook is the most impressive part of the process, at least from a design perspective. A tower of four ovens (they look like rocket boosters, naturally) sits just outside the main refrigerator, with topped pizzas flowing out onto a perpendicular conveyor belt. Depending on the programming and specific array of toppings, pizzas will get varying temperatures and times within each oven (vegetables require more heat due to their higher water content; meats need less). The steel ovens have three heating elements that mimic a wood-fired oven in its intensity, including a metal plate on the bottom heated by direct flame like a plancha. Above, two fire rings produce heat above each pizza, the outer one for browning and cooking the crust while the inner one is for toppings. Within minutes each pizza is cooked, a speed that makes this machine incredibly efficient. Pies flow back toward the end of the machine where a human worker will slice and box them for serving.

Stellar Pizza

Stellar Pizza

The pizza itself looks and smells impressive, like something you would get at Blaze or Pieology or maybe even 800 Degrees. The slow-fermented dough has zero additives and needs 48-plus hours to rise. Tsai, the company’s CEO, loves to boast about the provenance and purity of the ingredients, like the King Arthur flour, the lack of any stabilizers or preservatives in the dough, or even the best-quality low-moisture mozzarella cheese. But the end product is still hovering in the middle ground of appeal, something a notch above delivery and maybe three notches above frozen. That’s because the pizza is supposed to be tasty for its price point: $7 for a cheese, a little more for some toppings, and maxing out at $10 fully loaded. That means it’s a few dollars cheaper than Blaze or MOD Pizza, and certainly more affordable than an artisanal, handmade pie from Superfine or Full Proof, though it’s important to note that the latter two are small businesses operating with storefronts, insurance, payroll, and all the rest — during a pandemic no less. Stellar Pizza wants to play a different game.

There are cameras strategically placed everywhere so engineers can get close-up views of every part of the process, displayed in security-footage style all packed into a large TV mounted to the side. It’s fun to just stand in front of that TV and dart around to see what’s happening to each pizza. I joke to Tsai that live broadcasts of this screen would make decent Twitch content, to which he answers that they’ve considered sending people links to the footage of their pizza being cooked, both to engage with customers and have an answer for any mistakes.

When I take a first bite, I’m struck by how normal it is. Most pizza is good, but this is a step above standard, with a nice dark brown on the bottom and sides of the crust, almost reaching that pleasant char on artisan pizzas. But its appearance is almost unsettlingly perfect: The toppings are cut into homogeneous pieces, laid out so evenly that it looks like the plastic display foods outside of a Japanese restaurant. I wish the sauce was more garlicky or peppery, imbued with herbs and aromatics instead of tasting like basic tomato. But if this was served to anyone on the street that didn’t know how it was made, there’s a good chance it would satisfy any notion of what it should taste like.

Tsai isn’t too enthused by my somewhat tepid response, but he’s not completely surprised either; there’s always going to be a portion of the dining public that will be skeptical of automated foods. With no people to criticize for the production of this pizza, the bad reviews are pinned to the engineers, the makers of the machine. Still, the team appreciates the honest feedback because that’s a part of the engineering process. Without failures and misfires and mistakes and bad outcomes, they can’t work to improve the technology.

Matthew Kang

Matthew Kang

That’s also where the conundrum of robot pizza lies. Cooking has long been one of the things that separates humans from the rest of the animal kingdom; development of ingredients, flavors, and dishes creates culture. But what happens when robots start taking over the cooking? Does it taste different because it was made by a machine or only because we know it was made by a machine? Whether you realize it or not, a huge portion of what we already eat is made by machines that cut, cook, and package, from the frozen section of Trader Joe’s to big parts of fast-food menus. But Stellar Pizza seems like a clear encroachment on freshly made-to-order pizzas served in restaurants.

It’s unlikely that Stellar Pizza will replace every pizza shop in America, but the overall pizza market is large enough that it’s hardly the point. Pizzas come in so many different styles, flavors, and types that Stellar would have to engineer more machines and advance its technology to try and emulate them, and adoption of these automations is fairly slow. Still, the fear for some remains that developments like these will lead to human job loss.

If the pandemic has shown anything, the situation with labor in the restaurant industry is more critical than ever. Shortages in labor from fine dining to fast food put pressure onto an already strained restaurant ecosystem contending with supply chain issues, changing regulations, and tighter-than-ever profit margins. And if Stellar Pizza’s machine can produce food more quickly, reliably, and consistently than human hands, at an approachable price, then the consumer does, in some ways, win. The next question is which consumers will latch onto Stellar’s promise. Right now, the company thinks the best way to create change is to own the brand, and make its own products at a local level instead of launching nationwide. They hired Fresh Brothers Pizza co-founder Debbie Goldberg to handle the marketing, a smart move since that company is now one of the largest independently owned pizza chains in the U.S. By controlling all aspects of the quality, marketing, and operation, Stellar hopes to compete with Domino’s and Pizza Hut one day.

The team is hopeful about their work, perhaps because the drudgery and stress of sending humans to Mars is comparatively more difficult than making a pizza robot. And they’re proud that their machine is something people can immediately experience, instead of a pie-in-the-sky notion of populating another planet. Still, everyone at Stellar is a little bit tired of eating pizza every day, even though, in this testing phase, it’s part of the job.

Stellar Pizza

With about six months before public release, Stellar is most interested in tweaking the machine so that it makes more delicious pizza with fewer failures. While I was there on my second visit, the dough press kept combining two balls and making a massive Venn diagram-looking shape. When I tasted pizzas on the second visit, the crusts were a little less developed from the oven, though the fermentation was more apparent and pleasant. The tweaking has to be programmed instead of taught, but they’re confident they have the data and engineering capability to produce the results they want.

This is really where the whole operation gets fascinating. That last part of human input — tasting and critiquing — is something no robot can do. I asked them how the team would account for variables like the amount of fermentation or gluten development in the dough that is difficult to quantify or measure. It’s something a trained pizzaiolo just knows when they poke a ball of dough or stretch it out by hand; even engineers can’t easily define a perfectly made dough. Hence the need for continuous feedback from consumers to tell them the pizza satisfies all the criteria of “good” pizza.

Stellar might have already designed a robot that can make fairly good food, but that machine won’t know what great pizza is until its human designers can program that into its code. Maybe then, Stellar’s pizza robot might understand the essence of doughy goodness, or at least how we as humans perceive it. If we learned anything from watching Wall-E, a machine might one day be able to manufacture the heart that goes into cooking.

Stellar Pizza is currently in its testing phase in Hawthorne and hopes to open to the public in the spring of 2022.