What is the difference Cold Processed, Cold Pressed, & Cold Filtered Whey Protein?

What Does "Cold Processed" Mean?

What Does Cold Processed Whey Protein Mean?

Sometimes called “Cold-Pressed,” and historically stemming from a standard filtration process used in the dairy industry called “Cold-Filtered.”

The term “Cold Processed” used to describe whey protein can only be used appropriately in two ways. Although the heavily marketed buzzword has been shamefully diluted over time, even conflated with many other unrelated aspects of whey processing, we are optimistic that this article draws clear boundaries as to what precisely cold-processed whey means. 

The Best Cold-Processed Whey Protein Isolate - 

A "cold-processed" whey protein powder is made with great care to reduce exposure to harsh temperatures that can alter, denature, and potentially render non-bio-available the fragile micro & macro (protein fractions) nutrients.

Cold Processed Whey Protein Powder Explained - 

  1. In the context of the “undenatured” or “non-denatured” topic, cold processed refers to the entire process of whey protein powder production from farm to the sealed pouch and the processing environment in between relative to temperature exposure.
  2. The evolution of the word stems from cold-filtering or cold-pressed. These terms only refer to the process of using mechanical separation via mesh sizes and screens or membranes to isolate out to a greater degree unwanted, simple sugars (lactose), fats, and any impurities for that matter that hold a larger volume than the chosen mesh size. AGN Roots Grassfed Whey is processed to > 90% protein by product-volume using mesh filter sized to 125 microns. 

No matter how the term is used or misused, the critical processes involved include:

  • Pasteurization
  • Curdling
  • Cold Micro-Filtering
  • Drying

When all executed correctly without heating the whey past its permanent deformation threshold, the whey protein product has become successfully knighted, “cold-processed.”

Cold Processed Grass-fed Whey Purchasing Tip: If the source of the whey protein is disclosed and happens to be a grass-fed cheese manufacturing company, it’s essential to understand that the handling of the whey protein takes a back seat to the cheese processing goals. 

The pasteurization and curdling temperatures are dictated with ONLY the cheese products to be made by the fromager (cheese maker) in mind. Cheese manufactures don’t typically have processing equipment for whey protein powder and thus sell the liquid whey directly from the curdling vat. There are terrific assurances associated with whey sourced from a high-quality cheese manufacturer.

Learn More Here: “Native Whey - Fact or Fiction”

What are the Pasteurization Temperatures for Cold Processed Whey Protein?

Below is a chart the illustrates the pasteurization methods ideal for getting the most out of your milk’s nutrition.  Vat Pasteurization & HTST are the methods within the “Cold Processed” window.

Click Here for a High-Resolution Pasteurization Chart

Why do dairy suppliers choose to use the HHST or UP pasteurization methods –

There are a few reasons; however, the most obvious happened to be true.

  • To save money and optimize output. As you can see from the chart above, the hotter the process, the less time it takes to go through it, thus milk production increases.
  • Reduce the chance of any microbial contamination or growth in the downstream processes (shipping). The hotter the process, the more stable the end product and less likely it will spoil in transit.

Remember – Whey contains a lot more than just protein; There are many other potent nutrients in that pouch, substances that can improve your blood pressure, immune health, and cognitive function. The integrity of these substances intact is beneficial to your nutrition, so it’s your goal to get the most of it, especially if you are paying a premium for it.

However, because dietary supplements in the USA post-market regulated under the DHSEA, brands are incentivized to optimize their liability (reduce) at the expense of the nutrition content of their products. They much rather have you ingest a product so cooked, that getting sick from it is extremely unlikely, especially when the marketing of the product doesn’t need to reflect or disclose any of this information. Never mind that your body doesn’t recognize the cooked whey as nutrients to utilize. 

Is Whey Protein Made From Cheesemaking Denatured? 

No, there is nothing about the cheese-making process (curdling) that will damage the protein structures of whey.

The opposite, however, is very real. In another article, we expose the business drivers behind a popular trend being marketed by several brands as superior, which is the “native” whey process (whey extracted from milk without the curdling process).

There are several reasons why, as a consumer of whey protein, you want to know that your whey came from cheese manufactures.  Procuring the highest-quality milk is always step one for the cheese-making industry. When whey protein traces back to a particular cheese manufacturer (or not), you can infer a great deal about the quality of the protein you have purchased. In this case, both the consumer of the whey protein and the fromager have the same motivations, high-quality milk.

What Temperature is the Whey Protein Exposed to During the Cheese-Making Process?

Whey protein always starts its life as raw milk. The next step of the process is pasteurization to ensure microbial safety. With the pasteurization process, complete, specific enzymes (curdling agents) called rennet along with heat are added to the milk Vat to begin the curdling. The combination of rennet and low heat creates an environment conducive to the failure of the milk’s natural emulsion. As the emulsion failures, coagulation of the casein proteins and fat begin to form the curds. These curds will float in the solution of liquid whey when this process is over.

It is important to note, the hottest temperature of this solution during this curdling process is < 103°F depending on the desired cheese; for softer cheeses, the heat applied may only reach about 88°F at its peak. Relative to pasteurization, the temperature of the whey required for curdling is relatively minor and does not cause any damage or even small denaturing to any of the protein structures.

In general, whey protein made from the process of cheese-making is the best path to ensuring ALL macronutrients endemic to grassfed whey make their way into your product!

Cold Processing vs. Ion Exchange (Making Whey Protein Isolate)

From liquid whey protein concentrates as low as 60% protein by volume to greater than 90% protein by volume Whey Protein Isolates. There are two standard methods used to filter or separate liquid whey into higher concentrations.

Method #1 – Ion Exchange

Ion exchangers primarily use the surface charge characteristics of the protein to isolate them out from everything else. The method has been around for a long time and is exceptionally sophisticated. Over time the Ion-Exchange method, however, has been subject to much scrutiny over the topic of denaturation.

Learn more: What is undenatured whey protein isolate? Visit our “undenatured whey protein explained” article.

The theory of “protein denaturation” is logical and has gained traction as a marketing buzz word. The term “undenatured” in this application, however, is inappropriate. For other reasons, the ion-exchange method used to filter grassfed whey protein has taken a back seat to cold membrane processing, but denaturing the whey protein is not one of them.

Acids have to be added to the solution to adjust pH to secure the attraction between the protein molecule’s surface charge and the resin separation containers located as part of the ion exchanger. After the separation occurs and the macro ingredients (Carbs & Fat & Lactose) have washed out, organic bases (usually a nitrogen compound) are then used to restore the desired pH. Although the theory is that the Acid + Base will cancel and mostly react out, this, unfortunately, is where the process becomes less beneficial than method #2 (cold processing via mesh filter). The remaining acid or base components that don’t chemically react out will remain in the final product.

Does Cold Processed Whey Protein Taste Better than Ion-Exchanged Whey?

If whey protein has exposure to denaturing elements such as a lousy ion-exchanger or operator, the resulting end product will undoubtedly taste less like fresh dairy and more like a salty chemically processed substance. M best whey protein isolates are sold 100% flavorless and without sweeteners. With today’s advancements in flavor systems and masking agents, if the product is not unflavored, any ability to gauge how the whey is processed will be lost.

Does the Ion-Exchange Method Denature Whey Protein?

As far as the impacts on the fragile grassfed whey protein structures resulting from a full swing in pH. The pH swing (range of pH change) in comparison to other food processing is quite common. If the pH change is precise with tight tolerance for error, there is virtually no risk of damaging the protein structures. Like all chemical processes, however, the human element of the process does carry the potential of getting it wrong and shocking the protein into a denatured state. While some pH denaturation is elastic and therefore reversible, there is no realistic way for the consumer to know if the ion-exchange method was applied with precision or not other than by taste, which is most often chemically masked. If you have the option, we recommend the traditional cold-processed method; it’s very much error-proof.

Is Acid Used In The Ion-Exchange Method?

Yes, hydrochloric acid and chemical reagent sodium hydroxide are added to the wet-whey to trigger the pH adjustment needed for the protein release.

In terms of the minimal amounts of acidic agents applied (hydrochloric acid) to the whey protein to reduce the pH, there is potential in this step for denaturing to occur.  If this execution of this step is correct, the pH of the solution is gently dropped over time to smoothly ionize the targeted components for extraction without reshaping the tertiary or quarternary structure of the proteins.

Does Ion-Exchanged Whey Protein Isolate Impact Glutathione Benefits?

When the pH drops, some of the amino acids are susceptible to taking on charge (becoming ionized). The nature of the ion-exchange method is to filter out the negatively charges particles with the Cation exchange membrane and the positively charged particles with the anion exchange membrane.

If Cysteine, the amino acid that plays the most critical part of the body’s production of Glutathione becomes ionized, it can, unfortunately, be filtered out.

The Ion-exchange method is known to form an unusual amino acid called “lysinoalanine.” This Amino Acid isn’t made out of thin air but rather scavenges necessary components from other amino acids with cystine as a prime target.  This phenomenon endemic to the ion-exchange method can then eliminate Cysteine from whey protein, leaving you without the vital ingredient to increasing your glutathione levels. 

Learn More about AGN Roots Grassfed Whey and our industry-leading cysteine concentrations in our “What is Glutathione?” FAQ.

Are Grassfed Whey Protein Macro -Nutrients (Protein Sub Fractions) Impacted by the Ion-Exchange Method?

The natural predisposition of the vital protein fractions β-lactoglobulin,α-lactalbumin, and BSA (Bovine Serum Albumin), is to carry a negative charge. The anion exchange membrane is positively charged and attracts these fractions. On the other hand, lactoferrin has the tendency to be positively charged and thus accumulates on the cation exchange membrane side. If this is accurate, it would mean the protein fractions become split from each other, severed electrochemically.

In conclusion, the majority of whey protein found in 5 lb. Tubs have undergone this method of filtration (excluding Native Whey). Although there is variance in the quality of the filtration, for the most part, it’s a fair process and is efficient, fast, and inexpensive. The most popular draw-back is more cringe-worthy than anything else around the involvement of harsh acids. Our concern would be regarding the ability to design around a pH that can target all the micro-nutrients with precision and accuracy without leaving behind critical protein fractions, both major and minor.

To learn more about protein fractions and all the benefits of the macro-nutrients within our grassfed whey - “What are Protein Fractions?.”

Method #2 – Cold Pressed (Cold Filtered)

This method involves mesh screens and is solely mechanical. Micro-filtration does not include changing the properties of the whey solution on a molecular level by any means, nor does it involve mixing any chemicals with the whey protein through the process. The process pressurizes liquid whey across a series of membranes designed to allow only specific micro-sized nutrients and smaller through, while particles more significant in size (fats, sugars, carbs) are filtered out. Cold filtering is undoubtedly the preferred method by most and is the most risk-averse, less prone to human errors or mistakes.

The Best Cold Processed & Undenatured Grassfed Whey Protein Isolate AGN Roots Grassfed Whey - 

At AGN Roots, we rely on cold filtration via micro-filtration screens (125 microns) and do not filter our Grassfed whey via the ion-exchange method.  All our grassfed whey is continuously run through the filtration process until the entire active system is > 90% protein.  

How is Whey Protein Dried, Dehydrated, Atomized?

Whey protein structures (macronutrients) are much more stable and protected while suspended in a liquid.  As we know, milk is fragile and can quickly perish for any number of reasons.

Dehydrating or drying whey protein into a powder form allows the finished product to withstand the test of time and last much longer than the original wet whey in terms of preservation.

In general, the removal of moisture down to levels below 6% eliminates the growth of unwanted micro-organisms.

There are three stages of low-temperature spray dryers. The first stage of spray drying is the atomization of the wet whey solution. Hot air is controlled at a temperature of 105°F with minimal tolerance and is introduced to the recently atomized whey particles moving in a counter-current fashion.

Atomization within the spray drying process is similar to the homogenizing process of dairy products. Pressure is used to push a non-uniform liquid through a small volume nozzle which forces temporary dispersion. This mechanism maximizes the available contact area between the water phase of the whey and hot air. Ensuring the atomized whey is uniformly exposed to the warm air is key to retaining nutrient properties sensitive to localized heat.

The second stage of the process includes the formation of dry particles. The droplets of whey begin to vaporize, and the dry matter becomes isolated.

The third and final stage is around collection and packaging. This process takes advantage of the low-temperature air and is commensurate with standard dehumidifying technology.

In summary, almost all dairy powders undergo some spray drying process. Similar to the other whey protein processes, the details matter.

The total time the whey is actually inside the dryer is a matter of seconds. The full exposure time of the droplets to hot air is minimal and optimized for an evaporation rate of water and the final desired moisture level when exiting the dryer chamber. 

Due to the limited exposure the atomized whey spends in the dryer, it’s essential to know that a temperature equilibrium between the air temperature and the inlet temperature of the whey coming from the micro-filtering lines doesn’t exist. To achieve temperature equilibrium between the inlet air and fragile macro-nutrients, exposure time in the dryer would require a substantial increase. The significance of total exposure time and specific heat of the various particles allows the effective temperature felt by the weakest bonds and macronutrients to be well below any denaturing threshold capable of impacting nutritional value.

Whey protein concentrates (WPCs) that contain a significant component of lactose (sugar) compared to a whey protein isolate (WPI) are very susceptible in this stage to denaturation. The denaturation of WPC during this drying stage is due to the crystallization of sugars triggered by the rapid change in temperature over a short time. When lactose in WPC reaches, it’s “glass” transition temperature due to either making contact with the dryer walls or the hot air inlet temperature tolerance being too loose; like all melted sugars, it will form crystals. 

Once crystallization is reached, reversing the process is not likely. The heat retained by the lactose becomes enough to damage the protein then and render it denatured. If you are set on consuming WPC; be sure to find a source that includes a pressurized or vacuum dryer designed to dry sugars.  

Thank you!

~ AGN Roots Grassfed Whey Team

[1] Membrane vs. Ion Exchange – Which Process is Best for Whey Protein Powder?.
Milk Specialties Global;  July 2013;
[2] Selective separation of the major whey proteins using ion-exchange membranes
Goodall S, Grandison AS, Jauregi PJ, Price J.
J Dairy Sci. 2008 Jan;91(1):1-10.
[3] Sternberg, M, and C Y Kim. “Lysinoalanine formation in protein food ingredients.” Advances in experimental medicine and biology vol. 86B (1977): 73-84. DOI:10.1007/978-1-4757-9113-6_5
[4] “Spray Drying of Dairy Products: a Review.” New Food Magazine, 20 Apr. 2017, www.newfoodmagazine.com/article/2090/spray-drying-of-dairy-products-a-review/.
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1 comment

Reading “Super Huamn” by Dave Asprey, he recommended taking Grass-Fed Cold-Pressed Whey Protein Powder. It made sense to me, I was always suspect of generic whey protein and figured there must be a higher quality version out there, and as far as I could tell, Grass-Fed dairy and meat products are far superior to industrial meat & dairy. That was clear to me, but the cold-press was not something I quite understood yet. Nonetheless, this article has been very informative on the cold-press process. Thank you!

John P.

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