Scientists Turn Plastic Bottles Into Cookies That Could Feed Astronauts

Engineered yeast can now convert PET plastic waste into edible protein.

The bottle that became a snack

The plastic water bottle you tossed in the recycling bin this morning could, in theory, end up as a cookie eaten by an astronaut on the way to Mars. Researchers at Southern Illinois University (SIU) Carbondale have engineered a strain of yeast that turns PET plastic and crop waste into real food ingredients, then 3D-prints the result into a protein-rich snack called µBites, pronounced “microbites.”

The team presented the work at the American Chemical Society’s Fall 2026 meeting, with partial funding from NASA’s Deep Space Food Challenge, a program searching for ways to feed crews on missions far from any grocery store.

Step 1: Dissolving plastic into syrup

Before any yeast gets involved, the plastic has to stop being plastic. Researchers grind up PET bottles and mix them with crop residue, such as corn stalks and leaves, then run the blend through a process called Oxidative Hydrothermal Dissolution. Hot, oxygen-rich water under high pressure breaks the mixture down into a water-soluble syrup, a kind of edible-adjacent slurry that microbes can actually digest.

Step 2: Yeast that eats waste and makes vitamins

This is where the project stops sounding like recycling and starts sounding like science fiction. Three genetically engineered yeast strains each do a different job on that syrup:

• One strain converts ethylene glycol from the broken-down PET into beta-carotene, a vitamin A precursor.
• A second strain produces vanillin, natural vanilla flavoring, from ferulic acid extracted from the plant waste.
• A third strain generates the proteins and fats needed to make the final product nutritionally useful, not just edible.

None of this happens by accident. Each yeast strain was deliberately modified to perform one specific conversion, essentially turning microscopic organisms into a tiny, waste-powered food factory.

Step 3: Printing and baking the cookie

The proteins, fats, and flavor compounds produced by the yeast are blended with fiber, starch, and sweeteners, then loaded into a 3D printer that shapes the mixture into cookie form. A microwave-based baking step finishes the job, producing a shelf-stable snack without a conventional oven or kitchen.

A finished µBites prototype, built entirely from plastic waste and plant scraps.

The numbers behind µBites

The lab results give this story real weight, not just novelty:

• The full conversion process, from bottle to cookie, involves 33 distinct steps.
• Taste testers scored the prototype 6.5 out of 9 in early sensory trials, a respectable result for a first-generation lab food.
• Production currently costs around 60 US dollars per kilogram, reflecting its status as a lab-scale prototype rather than a commercial product.
• The dissolution process converts more than 50 percent of the waste’s carbon content within just one to two days.

Nobody has eaten one yet

Here’s the part that keeps this story grounded: no one outside the lab has actually eaten a µBites cookie. The prototype is still awaiting formal food-safety clearance from regulators before it can reach anyone’s mouth. Third-party lab testing has already confirmed the cookies contain no toxins, heavy metals, allergenic residues, or pathogens, and critically, no leftover plastic makes it into the final product.

Researchers see the technology as a potential answer to two problems at once: plastic waste piling up on Earth, and food scarcity in places where growing crops isn’t an option, whether that’s a disaster zone or a spacecraft en route to another planet. As one team member put it, nature had already solved a version of this problem long before humans started trying, and this project simply points that same biological trick at the plastic humans created.