Where do protein companies get their protein from? Sourcing, Manufacturing, and Quality

January 8, 2026 •

4 min read

Did you know that whey protein, a common base for supplements, was historically considered a waste byproduct of the cheese-making process? Today, protein companies utilize advanced techniques to source and process raw materials from both animal and plant origins to create the powders found in stores.

Quick Summary

Protein powders are derived from diverse animal and plant sources, such as milk, soy, and peas. The raw ingredients undergo extraction, filtration, and drying to create the final product, all while adhering to strict quality control measures.

Key Points

Diverse Sourcing: Protein companies obtain protein from both animal sources, like milk and eggs, and a variety of plant sources, including soy, peas, and brown rice.
Manufacturing Complexity: Raw ingredients undergo extensive processing, including filtration, concentration, and drying, to produce the final powder.
Quality Control is Critical: Reputable brands employ strict quality control measures, including third-party testing, to ensure purity and label accuracy.
Ethical Practices are Important: Many companies are responding to consumer demand by adopting ethical sourcing, using sustainable farming, and ensuring animal welfare.
Varied Absorption Rates: Different protein sources have distinct digestion rates, with whey being fast-absorbing and casein offering a slower, sustained release of amino acids.
Plant Blends for Complete Profiles: To ensure a complete amino acid profile, many plant-based protein powders are formulated as blends of different sources like pea and rice.

Sourcing and Processing of Animal-Based Proteins

Whey Protein

Whey protein, a widely popular and fast-digesting protein, is derived from cow's milk. The journey begins at dairy farms, where milk is collected from cattle. The milk is first pasteurized to eliminate harmful bacteria. In the subsequent cheese-making process, enzymes are added to the milk, causing it to separate into solid curds (used for cheese) and a liquid part—the whey.

The raw liquid whey is then transferred to a manufacturing facility for filtration and purification. This is where different types of whey are produced:

Whey Protein Concentrate (WPC): The liquid whey is passed through ceramic filters in a process called ultrafiltration to remove most of the fat and lactose. The resulting liquid is then spray-dried to form a powder that is typically 70-80% protein.
Whey Protein Isolate (WPI): This is a purer form created by further processing WPC to remove even more fat and lactose, yielding a powder that is 90% or more protein.
Whey Protein Hydrolysate (WPH): WPI undergoes an additional process that breaks down the amino acid bonds, making it pre-digested and easier for the body to absorb.

Casein Protein

Like whey, casein is another protein derived from milk, but it makes up about 80% of the protein content. Casein forms the solid curds during the cheesemaking process and digests much more slowly than whey. This slow-release property makes it a popular choice for sustained amino acid delivery, often taken before bed.

Egg Protein

For those who prefer a non-dairy animal-based option, egg protein is a common choice. It is made by separating the egg whites, which have the highest protein content, and then pasteurizing, filtering, and drying them into a powder. Egg protein is considered a high-quality, complete protein, meaning it contains all nine essential amino acids.

Sourcing and Processing of Plant-Based Proteins

Soy Protein

Soy protein is extracted from soybeans, which are first dehulled and defatted to produce soy flour. This flour is then further processed to create concentrates or isolates. Soy protein isolate, for example, is highly refined to achieve at least 90% protein purity.

Pea Protein

Sourced from yellow split peas, pea protein has grown significantly in popularity. The process involves:

Harvesting and cleaning the yellow split peas.
Milling the peas into a fine flour.
Using wet filtration to separate the protein from starches and fiber.
Concentrating the remaining protein paste.
Spray-drying the paste into a fine powder.

Brown Rice Protein

This vegan protein source comes from brown rice and is often combined with other plant proteins, like pea, to achieve a more complete amino acid profile. The rice undergoes a process of enzymatic separation to isolate the protein.

Other Plant Protein Sources

Many protein blends use a combination of different plant sources to provide a complete amino acid profile and appealing texture. Other popular plant-based sources include:

Hemp seeds
Chia and flax seeds
Pumpkin seeds
Cranberries
Artichokes

Quality Control and Ethical Considerations

Protein companies place a high priority on sourcing high-quality ingredients and maintaining strict quality control throughout the manufacturing process. Reputable manufacturers follow Good Manufacturing Practices (GMPs) and often engage in third-party testing and certification from organizations like NSF or UL. This ensures products are tested for contaminants, purity, and that the label claims are accurate.

Ethical sourcing is also a growing concern for consumers. Many brands highlight their commitment to fair trade, sustainable farming practices, and animal welfare. For example, some whey protein companies source their milk from grass-fed cows, avoiding the intensive factory farming methods common in the dairy industry. Consumers can look for organic certifications or transparent brand information regarding their ingredient origins to make informed decisions.

Protein Source Comparison


Feature	Whey Protein	Casein Protein	Soy Protein	Pea Protein
Source	Cow's milk	Cow's milk	Soybeans	Yellow split peas
Digestion	Fast	Slow	Medium	Medium
Amino Acids	Complete	Complete	Complete	Complete (when isolated or blended)
Best Used For	Post-workout recovery	Overnight recovery, satiety	Versatile, vegan option	Vegan alternative, hypoallergenic
Taste	Often neutral, can be flavored	Neutral, can be chalky	Neutral	Mild, sometimes earthy
Lactose Content	Varies (isolate is lower)	Contains lactose	Lactose-free	Lactose-free

Conclusion

Protein companies source their key ingredients from a diverse range of animal and plant-based origins, each with its unique sourcing and manufacturing process. From the ultrafiltration of milk to create whey to the enzymatic separation of yellow split peas, the journey from raw material to a final protein powder is a complex and highly controlled one. With growing consumer demand for transparency, many brands are also prioritizing ethical sourcing and sustainability in their supply chains. Understanding these origins and processes empowers consumers to choose the right protein supplement that aligns with their dietary needs, preferences, and values. For more information on dietary supplements, consult reliable health sources like Harvard Health.

The Journey to a Scoop of Protein Powder

The Milk-to-Whey Process

Milk is collected from dairy farms, often grass-fed for organic brands.
Milk is pasteurized to eliminate bacteria.
Enzymes are added to separate milk into curds (casein) and liquid whey.
The liquid whey undergoes filtration (e.g., ultrafiltration) to remove lactose and fat, concentrating the protein.
Concentrated liquid whey is spray-dried into a fine powder.
The unflavored powder is blended with flavors and other additives before packaging.

The Pea-to-Powder Process

Yellow split peas are harvested and cleaned.
The peas are ground into a fine flour.
Wet filtration is used to separate the protein from starches and fiber.
The protein solution is concentrated and then spray-dried.
The final powder is tested, blended, and packaged for sale.

Frequently Asked Questions

No, protein powder can be sourced from both animals and plants. Common animal sources include milk (for whey and casein) and eggs, while plant-based options are derived from soybeans, peas, brown rice, and hemp.

Whey protein is separated from milk during the cheesemaking process. After milk is coagulated with enzymes, the liquid part (whey) is separated from the solid curds (casein), then filtered and dried into a powder.

Whey isolate undergoes more filtration than whey concentrate. This extra step removes more fat and lactose, resulting in a purer powder with a higher protein percentage (90%+ for isolate vs. 70-80% for concentrate).

Reputable companies adhere to Good Manufacturing Practices (GMPs) and use processes like third-party certifications from organizations like NSF or UL. They test batches for contaminants, purity, and label accuracy.

Common plant-based protein powder sources include yellow split peas, soybeans, brown rice, hemp seeds, and various other seeds and legumes.

While some plant proteins like soy are complete on their own, many plant-based protein products combine multiple sources (e.g., pea and rice) to ensure a complete amino acid profile.

Ethical sourcing involves ensuring that ingredients are produced responsibly and sustainably. For animal-based protein, it may involve sourcing from grass-fed farms with better animal welfare standards. For plant-based, it can include fair trade and sustainable farming practices.