Freshwater prawn

Use the scientific name when a common market name could be ambiguous.

Big, firm, faintly lobster-like - and the fastest of all to spoil from the head down.

Retail naming varies. The exact bag still needs its own identity check.

Open a real product record to see count, form, treatment and retailer observations.

Hours to days of chilled transport happen first, with autolysis running the whole time - and for pandalids that clock is fast, with myosin heavy chain degradation detectable within five hours on ice. Then the product freezes, often as a block with a long thermal path to the centre, so interior shrimp cross the damage band slowly. The physics is peer-reviewed; the block-versus-IQF comparison itself is industry assertion, with no head-to-head trial found.

Over-sulfited shrimp above roughly 100 ppm is described by the extension literature as translucent, glassy, plump, slippery and explicitly HARD TO COOK. That is a chemical-residue diagnosis, not a technique failure, and readers currently blame themselves for it. Note also that sulfite concentrates in the non-edible parts - whole samples run up to four times the level of edible parts - so it bears on whether the heads can be used for stock.

Freezing rate sets ice crystal size: above 2 cm/h gives 10-50 micron crystals confined to interstitial spaces, against 100-300 micron dendritic crystals that pierce membranes below 0.5 cm/h. Frozen at sea crosses the -1 to -5C damage band once, fast, hours after capture, and before autolysis has run. It is also what underwrites raw service for Groups B and C, and it is why royal red and Argentine red are frozen on board as standard - the heads degrade at surface temperature. Note the state does NOT by itself satisfy the Food Code parameters: commercial product held at -18C does not meet the -20C for 7 days requirement.

A treated shrimp still poaches, simmers and boils exactly as its group predicts - it simply weeps. But no species is firm enough or large enough to sear a crust through 5-25% added mobile water: the pan spends the entire ~100-second budget boiling off exudate at 100C and never reaches the 140C the surface needs. So for grill and pan_sear the state wins outright, and a Group A jumbo behaves worse than an untreated Group B shrimp would.

This is previously-frozen product that has taken an extra freeze-thaw cycle plus an unknown period at counter temperature - time spent walking through both the cathepsin optimum band and the bacterial growth range. Freeze-thaw damage is monotonic in cycles: after 21 cycles colony counts and TVB-N exceed the edible standard, with hardness, elasticity and chewiness all declining, and the published recommendation is fewer than eight. The consumer consequence is blunt and worth stating plainly on every page: buying the same product still frozen and thawing it once at home is strictly less damage.

Hardness is an integral of time at temperature, and cook loss, shrinkage and hardness correlate at 97.8, 92.3 and 88.4 percent. Every reheat moves further up the same monotonic curve and nothing re-hydrates. The only technical route back is very prolonged braising, which softens via collagen-to-gelatin at the cost of everything else. DIRECT ANSWER to the brief's question: for a precooked salad-shrimp bag, Group B membership no longer decides anything about METHOD - R15 has decided all eight cells. What group membership still decides is flavour framing (what to dress it with) and the purchasing lesson (that raw-grade amaebi is a different product on the same shelf). Therefore the Use block must ask what STATE the bag is in BEFORE it asks what species it is.