The Short Answer
Sodium tripolyphosphate (STPP) is an industrial chemical added to seafood to make it absorb excess water. You should absolutely avoid STPP because it degrades the texture of your food and artificially inflates the price.
Seafood processors use this chemical bath to plump up shrimp, scallops, and fish fillets before freezing them. While the FDA considers it generally recognized as safe, STPP can increase a product's weight by up to 25%—meaning you are literally paying seafood prices for tap water. Is Sodium Tripolyphosphate Safe
Why This Matters
If you've ever tried to sear a scallop or sauté a shrimp, only to watch it boil in a pool of milky white liquid, you've experienced STPP. This chemical forces muscle fibers to hold unnatural amounts of water, making it impossible to get a proper sear. The water evaporates during cooking, leaving behind a shrunken, rubbery piece of protein. Is Frozen Shrimp Treated
Beyond the kitchen frustration, this is a massive economic scam. Consumers are unknowingly paying top dollar for hidden water weight. Class-action lawsuits have targeted major brands for using STPP to artificially pump up their "100% whole fish" products by 13% or more. Is Frozen Fish Healthy
There are also serious questions about long-term health impacts. Excessive dietary phosphates are linked to kidney strain and cardiovascular issues. While STPP is safely used as a cleaning detergent and paint additive, its presence in our food supply is driven entirely by corporate profit, not consumer benefit. What Is Sodium Tripolyphosphate
What's Actually In Treated Seafood
- Sodium Tripolyphosphate (STPP) — A commercial emulsifier and suspected neurotoxin in large doses that is used to swell protein fibers. Is Sodium Tripolyphosphate Safe
- Hidden Tap Water — Treated seafood can hold 10% to 25% more water, meaning a massive portion of your purchase is just liquid.
- Excess Sodium — STPP drastically spikes the sodium content of the fish, causing hidden issues for those monitoring their blood pressure.
- Sodium Bisulfite — Another common chemical often used alongside STPP on shrimp to prevent the shells from darkening. Is Frozen Shrimp Treated
What to Look For
Green Flags:
- The word "Dry" — This is the official seafood industry term for scallops that have not been soaked in a chemical bath.
- "Chemical Free" labeling — Premium brands will explicitly state they do not use STPP or added water. Best Frozen Fish Brands
- Shell-on shrimp — Phosphates are almost exclusively applied to peeled shrimp, making shell-on options a safer bet.
Red Flags:
- "Wet" seafood — If a fishmonger calls their scallops "wet," they are confirming they have been soaked in STPP.
- "Added to retain moisture" — This innocent-sounding phrase in the fine print is a legal loophole for declaring STPP.
- Milky white liquid — If your seafood shrinks dramatically and oozes a thick, soapy white liquid while cooking, it was chemically treated.
The Best Options
Finding clean seafood requires looking past the front label. Always check the ingredient list or ask your fishmonger directly for dry options. Best Frozen Fish Brands
| Brand | Product | Verdict | Why |
|---|---|---|---|
| North Coast Seafoods | Naked Shrimp | ✅ | Explicitly chemical-free with no STPP or added water. |
| Prime Shrimp | Frozen Shrimp Burgers | ✅ | Made from responsibly sourced shrimp with zero STPP. |
| Bering Bounty | Wild Alaskan Seafood | ✅ | 100% clean catch with no preservatives or dyes. |
| Van de Kamp's | Frozen Breaded Fish | 🚫 | Facing lawsuits over excessive STPP water-weighting. |
| Generic Supermarket | "Wet" Scallops | 🚫 | Plumped with up to 25% water weight and chemicals. |
The Bottom Line
1. Always ask for "dry" scallops. This guarantees you are getting 100% scallop meat without chemical water-plumping.
2. Read the fine print. Avoid any frozen seafood that lists STPP, sodium tripolyphosphate, or "solution added to retain moisture." Is Frozen Shrimp Treated
3. Buy shell-on shrimp. It requires slightly more prep work, but it naturally avoids the chemical baths used on pre-peeled varieties. Fresh Vs Frozen Fish
FAQ
Is sodium tripolyphosphate safe to eat?
The FDA considers STPP "Generally Recognized As Safe" in small amounts, but high phosphate intake is linked to kidney issues and calcium depletion. It is an unnecessary industrial additive used purely to inflate corporate profits. Is Sodium Tripolyphosphate Safe
Can I wash STPP off my seafood?
No. The chemical is absorbed deep into the muscle tissues of the fish. Rinsing or soaking your seafood will not remove the STPP or the excess water weight it trapped inside.
Why does my shrimp taste like soap?
That soapy, slightly metallic taste is a direct result of STPP. When heavily treated seafood is cooked, the chemicals concentrate, ruining the natural sweetness of the shrimp or scallops. Is Frozen Shrimp Treated