Chemical-Free Seafood: No STPP, No Altessa, No Additives, The Intershell Standard

That sounds obvious. But many seafood products sold in the United States are treated with sodium tripolyphosphate (STPP), Altessa, citrus-based soaking agents, phosphate blends, or other water-retention additives before they reach your plate. These treatments can add weight, alter texture, and change how seafood behaves in your kitchen.

At Intershell Seafood, we have a single non-negotiable rule:

We process and freeze scallops, lobster, fish, and clams without STPP, Altessa, phosphate blends, or any chemical additive designed to change weight, appearance, or moisture level. Our seafood is handled clean, from the ocean to your door.

This guide explains what chemical free seafood means, how to identify no STPP seafood, why untreated seafood cooks better, and how to choose reliable chemical free seafood sources for home cooking, restaurants, and wholesale buying.

What Is Chemical Free Seafood?

Chemical free seafood is seafood processed and frozen without water-retention additives, phosphate treatments, citrus-based soaking agents, or other chemicals that alter the product's natural weight, texture, or shelf life. It is also called untreated seafood, additive free seafood, no STPP seafood, or phosphate free seafood.

In practical terms, it means:

Chemical free seafood arrives at its natural weight. It cooks the way nature intended. And it tastes the way it should.

Why Is Seafood Treated With Chemicals?

Seafood additives became common in commercial processing for one primary reason: weight.

When seafood absorbs water through a phosphate or citrus treatment, it becomes heavier. A scallop that weighs 1 oz naturally may weigh 1.3 oz after treatment. Multiply that across thousands of pounds of product and the financial advantage to processors is enormous.

For the buyer, whether a restaurant chef or a home cook, the math works in the opposite direction. You pay for water. You cook off water. You end up with less seafood than you purchased.

Beyond weight, there are three additional reasons processors use additives:

STPP in Seafood: What You Need to Know

STPP stands for sodium tripolyphosphate. It is classified as a food additive, known as E451 in Europe, and is widely used in commercial seafood processing, particularly for scallops, shrimp, fish fillets, and lobster tails.

How STPP Works

STPP is alkaline. When seafood is soaked in a STPP solution, the alkaline environment causes muscle proteins to retain more water. The seafood swells, becomes heavier, and holds that extra weight until it hits heat.

What STPP Does to Cooking Performance

When treated seafood hits a hot pan, the extra retained water is immediately released. Instead of searing, the seafood steams in its own liquid. This leads to:

This is the single biggest reason professional chefs seek out dry scallops and other untreated seafood. The cooking performance difference is immediate and undeniable.

How to Identify STPP-Treated Seafood

The safest method is to buy from a supplier who clearly states their no-additive policy, like Intershell.

Altessa and Citrus-Based Seafood Treatments

In recent years, some processors have moved away from phosphate-based additives and toward treatments marketed as "natural," including citrus-extract treatments like Altessa.

The marketing is designed to sound cleaner. But the function is similar.

Altessa and similar citrus-based treatments are applied to seafood to:

These are not food safety measures. They are presentation and weight-retention tools.

At Intershell, our position is straightforward: if a treatment is designed to change how seafood looks, weighs, or performs, we do not use it. We do not keep Altessa in our facility. We do not use citrus retention baths. We do not apply any treatment whose purpose is to modify the seafood's natural state.

Dry Scallops Are One Example of Our Chemical Free Seafood Standard

Scallops are one of the clearest examples of why chemical free seafood matters.

Many scallops in the market are sold as "wet scallops." These scallops may be soaked in STPP or other water-retention solutions to help them hold more moisture. This can make them look plumper and brighter, but it can also affect how they cook.

When wet scallops hit a hot pan, they often release extra water. Instead of forming a golden crust, they may steam in their own liquid. This can lead to poor browning, shrinkage, and a softer texture.

Intershell scallops are dry scallops. That means they are not treated with STPP or water-retention additives. They keep their natural texture, natural sweetness, and clean ocean flavor.

This same standard applies across our seafood, not just scallops. Our lobster, clams, fish, fresh seafood, and frozen seafood are also handled without STPP, Altessa, or additive treatments.

Want to learn the full difference between dry scallops and wet scallops? Read our complete guide on dry scallops and chemical free scallops.

Why Chemical Free Seafood Cooks Better

The difference between treated and untreated seafood is most obvious in the kitchen.

For Searing and Browning

Untreated seafood has a dry, natural surface. When it contacts a hot pan, the Maillard reaction begins almost immediately. This produces the golden-brown crust that defines a well-seared scallop or fish fillet. Treated seafood cannot do this as well because moisture escapes from the tissue, preventing the surface from reaching the temperature needed for browning.

For Texture

Without excess retained water, seafood proteins firm up correctly during cooking. The texture is clean and natural, not rubbery and not mushy.

For Flavor

Added water dilutes flavor. Untreated seafood concentrates its natural sweetness, brininess, and oceanic character during cooking. The difference is particularly noticeable in scallops, lobster, and delicate white fish.

For Portion Control in Restaurants

Chefs who use chemical free seafood get more predictable yield. A 2 oz scallop stays close to 2 oz after cooking. Treated scallops can lose 20 to 30% of their weight as water evaporates, which means portion sizes can shrink unexpectedly and food cost calculations can go wrong.

Chemical Free Seafood Sources: Why Intershell Keeps It Pure

Not all chemical free seafood sources follow the same handling standards. At Intershell Seafood, purity is not a tagline. It is a documented operational standard across our scallops, lobster, fish fillets, clams, and frozen seafood.

We process the following species without STPP, Altessa, or any additive treatment:

We do not keep STPP or Altessa in our processing facility. This is not a matter of policy paperwork. It is a physical absence. There is nothing to accidentally use.

Every product that passes through Intershell is handled with:

Chemical Free Seafood for Restaurants and Wholesale Buyers

Professional kitchens have specific reasons to care about additive free seafood beyond taste.

Intershell provides wholesale chemical free seafood for restaurants, hotels, seafood markets, and foodservice operations throughout the region. For chefs and buyers looking for dependable chemical free seafood sources, we offer consistent supply, reliable delivery, full traceability, and a clear documented no-additive standard.

Chemical Free Seafood for Home Cooks

You should not need a culinary degree to get properly handled seafood.

When you order from Intershell's online store, you receive seafood that cooks the way it should, without hidden water, without additives, and without guesswork.

The difference is most noticeable in simple preparations:

Good seafood, handled correctly, does not need tricks.

How to Tell If Seafood Has Been Treated

Seafood packaging can be confusing, especially when products are sold in bulk, repacked, or described with unclear terms. Here is what to look for:

The simplest test is to buy from a supplier who commits, in writing, to no additive treatments.

That is what Intershell does.

How to Choose Chemical Free Seafood Sources

Choosing the right seafood source matters because labels can be unclear, especially with frozen seafood, bulk seafood, scallops, shrimp, lobster, and fish fillets. A trusted chemical free seafood source should clearly explain how the seafood is handled before it reaches the customer.

Before buying, look for a supplier that can clearly confirm:

Intershell Seafood follows this standard by processing seafood without STPP, Altessa, phosphate blends, or artificial water-retention treatments. That means customers receive seafood at its natural weight, with natural texture, clean flavor, and better cooking performance.

Frequently Asked Questions