Usually salvageable for the next batch, even if this one is already stuck to the wok. A slimy or gummy coating means the starch-and-egg-white layer never set into the thin seal it's meant to become, and a soapy, mushy texture underneath it means baking soda did more to the meat than you wanted it to. Those are two different failures with two different fixes.
What the coating is actually built to do
Cornstarch granules swell when they hit heat and water, thickening into a semi-solid film wrapped around each piece of meat. Egg white does something similar, coagulating into a thin skin of its own. Together they're a heat shield sitting between the meat and the wok, not a flavor addition. The shield is what lets a stir fry run at screaming-hot heat without the outside of the meat seizing and drying out before the inside is done.
That only works if the film actually sets. A film that never firms up is still starch and egg suspended in liquid — sticky, clingy, and exactly the texture people mean by "gummy."
The other version: baking soda instead of a coating
Some velveting recipes skip the coating entirely and use a baking soda rub instead. This is a different mechanism doing a different job. Baking soda raises the pH at the meat's surface, and muscle proteins bind to each other less tightly in that more alkaline environment. Loosened proteins are better at trapping water inside the fiber, so the meat cooks up moist even at high heat. Nothing is sealing anything in from outside — the meat itself is holding more water than it would otherwise.
How much baking soda turns into a problem
For about a pound of thin-sliced meat, a working range is a half to three-quarters of a teaspoon of baking soda dissolved in a tablespoon of water, tossed with the meat, and left 15 to 20 minutes before rinsing it off and moving on to the actual marinade. Push past a full teaspoon per pound, or skip the rinse, and two things go wrong at once. The meat picks up a faint soapy, mineral taste, because that's literally the flavor of sodium bicarbonate residue. And the surface proteins denature past the point of holding any structure — they go slack and slick instead of tender, which reads as slimy and gets mistaken for undercooked meat.
Why the coating turns gummy instead of crisp
Two separate causes produce the same result. The first is a marinade that's too thick relative to how much liquid is in it — a paste that clumps unevenly instead of coating each piece thinly. The second is a blanch that's too cool to fully gelatinize the starch, so it stays tacky rather than setting into a film. Water for blanching should sit just below a simmer, around 200 to 210°F (93–99°C); a hard boil knocks the pieces around and can overcook thin slices before they ever reach the wok. Oil run at 275 to 300°F (135–150°C) does the same pre-cooking job with a drier result.
Can this batch be saved
If the meat is still raw and the coating looks pasty, thin it. A splash of water or rice wine worked into the marinade and tossed again spreads the starch more evenly over the surface instead of leaving it in clumps.
If it's already cooked and gummy, there isn't much to do about the interior — the starch layer set the way it set. A short pass in a dry, very hot pan can crisp the outside further, but slime that came from under-gelatinized starch on the inside of the coating won't cook away after the fact.
What it should look like before it hits the wok
Pieces should separate from each other, not clump into a solid mass. The coating should look matte, not glossy or dripping. Dropped into hot oil or water, it should turn from translucent to opaque within 30 to 45 seconds — that's the starch setting in real time. If it stays slick and translucent well past a minute, the liquid wasn't hot enough to do its job.