What does Cold Processed Whey Protein Mean?
Sometimes called “Cold-Pressed”, and historically stemming from a common filtration process used in the whey protein industry called “Cold-Filtered”, cold processed can be used in a few ways.
- In the context of the “undenatured” or “non-denatured” topic, cold processed often refers to the entire process of whey protein processing and the temperatures the milk and later whey proteins are exposed to as a function of damaging the more fragile micro nutrients and protein fractions.
- The evolution of the word actually stems from cold-filtering or cold-pressed. This only refers to the process of using mechanical separation via mesh size and screens or membranes to isolate out further unwanted, simple sugars (lactose), fats, and any impurities for that matter that hold a larger volume than the chosen mesh size.
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.
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.
Coagulation (Curdling) –
Typically, whey protein starts its life as milk that has been exposed to heat and curdling agents. This heat was used in conjunction with a rennet to initiate coagulation of the casein proteins and fat which together will form a curd. These curds will float in the solution of liquid whey when this process is over. The typical highest temperature of this solution is < 103°F depending on the desired cheese, for softer cheese, the heat applied may reach about 88°F at its peak. This said, the heat required for this process, is relatively minor and does not cause any major damage to the nutrients that naturally occur in whey.
Cold Filtration / Cold Pressed
From liquid Whey Protein Concentrates as low as 60% protein by volume to > 90% Whey Protein Isolates
Filtration Process – There are essentially two methods used to filter or separate liquid whey into greater concentrations.
Method #1 – Ion Exchange
Ion exchangers essentially use the surface charge characteristics of the protein to isolate them out from everything else. The method has been around for a long time is extremely clever however over time has been subject to much scrutiny over the topic of denaturization. The theory is sound, however the way the theory is executed is the source of the potential problems. Acids have to be added to the solution to adjust pH in order 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, base is added to restore the desired pH. Although the theory is that the Acid + Base will cancel and essentially react out, this unfortunately is where the process becomes less beneficial that method #2. Whatever acid or base doesn’t chemically react out, is in most cases left behind in the final product. This said, the pH adjustment range itself when compared to other foods is fairly common, meaning the changes in protein are not considered denaturation as part of the pH adjustment process, but rather reversible and still intact.
In conclusion, the majority of whey protein found in 5lb tubs has undergone this method of filtration. Although there is variance in the quality of the filtration, for the most part it’s a sound 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.
Method #2 – Cold Pressed (Cold Filtered)
This method involves mesh screens and is solely mechanical. Micro-filtration does not involve changing the properties of the whey solution on a molecular level by any means nor does it involve adding any chemicals to the whey 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 greater in size (fats, sugars, carbs) are filtered out. This is a preferred method by most, and is definitely the simplest method less prone to human errors or mistakes.
At AGN Roots we rely on cold filtration via micro and ultra-filtration screens and do not filter our Grassfed whey via the ion-exchange method.
~ AGN Roots Grassfed Whey Team