Microphotography of Raw and Processed Milk

A Pilot Study

Raw milk is a colloid, in which fat globules of various sizes are dispersed within a watery phase of dissolved proteins, carbohydrates, vitamins, electrolytes and minerals, along with low levels of probiotic bacteria such as lactobacillus. The purpose of this pilot study is to examine whole milk—raw and processed— to look for any differences in its colloidal structure that can be seen using an optical microscope. In particular, we looked for differences between unpasteurized raw whole milk compared to whole milk that is pasteurized (heated to 170 degrees F for nineteen seconds) or ultrapasteurized (heated to 280 degrees F for two seconds, using superheated metal plates and steam, and then chilled). We also looked at the effects of homogenization of milk. Milk samples were observed under the microscope over a large range of magnification and two types of illumination, bright field and dark field.


Five types of commercial fresh whole milk were sampled, as follows:

1. Ultrapasteurized, homogenized whole milk

2. Organic pasteurized (not ultrapasteurized), homogenized whole milk

3. Organic pasteurized (not ultrapasteurized), unhomogenized (“cream top”) whole milk

4. Raw whole organic milk, brand “A”

5. Raw whole organic milk, brand “B”

The milk was purchased and sampled on the same day and kept under the same refrigeration until minutes before sampling. Because milk is a heterogeneous liquid, each milk container was gently inverted in the carton or bottle several times in a similar fashion to mix it just before sampling. Using a pipette, a small volume (50 microliters) of milk was placed on a clean glass microscope slide. A glass cover slip was placed over it to spread out the droplet. This constituted a sample slide. Sample slides were made just before observation and photography under the bright-field microscope and again just before dark-field observation, so that all samples observed were individually and similarly prepared just before microphotography.

The following magnifications were used with bright-field microphotography, in which the sample was illuminated from below with a tungsten lamp: 75x, 175x, and 350x.

The following magnifications were used with dark-field microphotography, in which the sample was edge-illuminated with a xenon lamp using a dark-field condenser: 500x, 800x, 1200x, 2100x, and 4200x. We achieved higher magnifications than the usual limit of light microscopy by means of digital optical enhancement. Altogether eight different magnifications, ranging from 75x to 4200x, were used to examine each milk sample.

Representative photographs were taken at least in triplicate for each power of magnification. Thus, at least twenty-four digital micro-photographs per type of milk were produced and compared, for a total of one hundred twenty photographs.


The one hundred twenty photographs were visually examined and qualitatively compared to examine the colloidal structure of the different types of milk at different magnifications and illumination.

Figure 1 shows raw milk at 175x under bright field, which shows a distinct colloidal structure of aggregates of the fat globules (white) amidst aqueous regions (dark). By comparison, Figure 2, which shows pasteurized unhomogenized milk also at 175x, shows much smaller aggregates of fat globules and a more uniform colloidal structure. Figure 3, which shows pasteurized, homogenized milk, and Figure 4, which is ultrapasteurized, homogenized milk, both at 175x, show no discernible colloidal structure at this magnification, as a virtually uniform gray field is seen. The horizontal scale for Figures 1 to 4 is 1.33 mm (millimeters) for the full width of each microphotograph.

FIGURE 1 Raw milk magnified 175 times


FIGURE 2 Pasteurized, unhomogenized milk, magnified 175 times


FIGURE 3 Pasteurized, homogenized milk magnified 175 times


FIGURE 4 Ultra-pasteurized, homogenized milk, magnified 175 times

Figures 5, 6, 7, and 8 show raw milk; pasteurized, unhomogenized milk; pasteurized homogenized milk; and ultrapasteurized, homogenized milk respectively. All photographs are 800x magnification.

Here, too, the raw milk shown in Figure 5 exhibits the most detailed ultrastructure, with greater variation in density of structure and material in regions throughout the photograph. Figure 6 showing pasteurized unhomogenized shows a less detailed structure at the same magnification compared to raw milk in Figure 5. A visual comparison of Figures 5 and 6 (unhomogenized milk) to Figures 7 and 8 (homogenized milk), shows how homogenization breaks down fat globules to a size that is no longer distinguishable at this power of magnification. Here the horizontal scale for these 4 figures is 0.29 mm (millimeters) for the full width of each microphotograph.

FIGURE 5 Raw milk magnified 800 times


FIGURE 6 Pasteurized, unhomogenized milk, magnified 800 times


FIGURE 7 Pasteurized, homogenized milk magnified 800 times


FIGURE 8 Ultra-pasteurized, homogenized milk, magnified 800 times

Figures 9 and 10 compare raw milk and ultrapasteurized, homogenized milk at 4200x. The horizontal scale for these 2 figures is 0.055 mm (millimeters, 55 micrometers) for the full width of each microphotograph.

The heterogeneity in size of the fat globules is seen for the raw milk, ranging in size up to 7 micrometers in diameter, with many in the range of 3 to 5 micrometers. However, the fat globules are smaller, more homogeneous in size, and indistinct in the processed milk, ranging in size only up to 2.3 microns, and with mostly smaller fat globules present.

FIGURE 9 Raw milk magnified 4200 times


FIGURE 10 Ultra-pasteurized, homogenized milk, magnified 4200 times

There is an apparent trend seen in these examples shown and all of the photographs taken, that the most highly processed milk— ultrapasturized and homogenized—shows the least distinct colloidal structure and the most homogeneity using the optical microscope. By contrast, raw milk shows the most distinct colloidal structure under the microscope at all magnifications observed, and this was the case for both commercial brands of raw milk. The raw milk ultrastructure consisted of a variety of sizes of milk fat globules, as seen under the highest powers of magnification, and in addition, patterns of organization of these globules when viewed under lower magnifications that appeared to be fractal in nature, that is, self-similar at various powers of magnification.


Raw whole milk is a natural colloid which has a structure that can be seen across a range of magnifications under a light microscope. In this regard, it is like a living system that shows an organized structure seen under the microscope at the same levels of magnification that living cells show organized structure, too. Thus, raw milk appears to have an organized yet complex and heterogeneous structure, as do living organisms, that is, the property of organized heterogeneity in various domains of order.

Pasteurization as well as homogenization alters the colloidal structure of milk, rendering it a less complex and more homogeneous liquid. Such milk has lost its structural complexity.

We could not distinguish any differences between pasteurized milk and ultrapasteurized milk from the microphotographs. Moreover, the milk that was pasteurized at the lower temperature but unhomogenized looked similar to raw milk at high magnifications as the heterogeneous size of the fat globules, ranging from about 2 to 7 micrometers, were similar.

It must be said that the optical microscope has limitations and cannot distinguish particles smaller than about 0.2 micrometers. Thus, any structure about this size or smaller cannot be resolved by light microscopy.

During sample preparation, it was noted that organic whole milk that is pasteurized but unhomogenized could not be completely mixed by hand mixing or shaking. Chunks of fat similar to butter were floating at the surface of the milk or stuck to the milk container, despite gentle inversion of the milk or even vigorous shaking for minutes. Thus, it appears that pasteurization itself has permanent effects on the fat globules of whole milk, making much of the fat congeal and separate from the watery phase of the milk, much like butter.


A colloid is a unique state of condensed matter in which small particles are dispersed in a liquid phase such as water. Milk is a complex aqueous colloid: a micro-structured aggregate of water, fat globules, various proteins, carbohydrates, electrolytes, vitamins and minerals. This may be compared to the colloidal state of the living cell itself, composed of similar constituents, which used to be called protoplasm, the primary material inside the living cell, as shown in the amoeba in Figure 11. Moreover, raw milk and blood (see Figure 12) look remarkably similar at high magnification.

FIGURE 11 Amoeba observed under dark-field microscopy, which has a similar colloidal structure to raw milk.


FIGURE 12 Normal healthy blood magnified 4200 times.

Scientific research shows that this colloidal state is dynamic, ubiquitous and appears to be integral to life’s functions. In fact, some natural colloids, such as proteins and fat particles in water, even display life-like responses to certain stimuli. That is, aqueous colloids—sols and gels—show some typical properties of living organisms, such as sensitivity to geo-cosmic rhythms (Piccardi, 1962), including circadian rhythms of day and night and solar rhythms such as the sunspot cycle of eleven years. Colloids can also absorb energy, such as light, and self-organize into larger, more complex forms, similar to living systems (Zhao et al., 2008). Some pioneering scientists working at the frontiers of water research think that many of the mysteries of life are intimately related to properties of aqueous colloids and water interfaces with membranes, a topic that is under considerable research activity at present (Pollack et al., 2006).

In light of the apparent relationship between colloidal structure and living function, let us reflect further on the results of this study. We have observed that pasteurization, ultra-pasteurization, and homogenization impact the colloidal structure of milk, altering its organizational integrity. Heat, as is used in pasteurization, is well known to denature the quaternary structure of proteins, deactivate enzymes, destroy vitamins and kill microbes. Homogenization affects the integrity of the fat globules, rendering them smaller and more uniform, and thus, alters raw milk’s colloidal ultrastructure, too. In summary, we have observed that processed milk loses “organized heterogeneity,” a term synonymous with the living state. Thus, whereas raw milk may be considered “alive,” processed milk is seen to be “lifeless.”


Piccardi G. (1962) The Chemical Basis of Medical Climatology. Springfield, IL: Charles C. Thomas, Publ.

Pollack GH, Cameron IL, Wheatley DN (editors) (2006) Water and the Cell. Dordrecht, Netherlands: Springer.

Zhao Q, Zheng J, Chai B, Pollack GH. (2008) Unexpected effect of light on colloidal crystal spacing. Langmuir 24:1750-1755.


This study was funded in part by the Weston A. Price Foundation. The author would also like to acknowledge Harry Jabs, who made helpful comments and edits of earlier drafts of this paper.

This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly journal of the Weston A. Price Foundation, Summer 2012.

Beverly Rubik, PhD, is president and founder of the Institute for Frontier Science in Oakland, California. She is also a faculty member at several universities and maintains a consulting practice. For more information about her work, contact her at brubik@earthlink.net or call (510) 428-4084.

12 Responses to Microphotography of Raw and Processed Milk

  1. olga says:

    Hi Dr.Rubik.
    Thank you for your precious study on comparing all these types of milk . After this study, what kind of milk do you consume?
    Thanks for your precious time.
    Olga Clement.

  2. Erik says:

    It would also be helpful to examine VAT/low-temperature pasteurized cream top milk to see how much of a difference that makes. Multiple sampling from the temperature and time range for VAT pasteurization would also be something interesting to see the results.

  3. Barbara Dunn says:

    That’s very interesting! The next question would be:”How does the difference in milk structure effect our health?”

  4. Melody says:

    I like the info. I am curious to see the pictures with goat milk. Suspect simular but with less issue of fat separating prior to and possible after pasturizing. Thank you for sharing yor study.

    • Laurie says:

      I also would like to know more about raw goats milk.
      My family of 8 have been drinking it for 35 years and my children are all healthy and have no health issues. Now that my husband and I are older I have time to make cheese and yogurt and this topic interests me.

  5. Babs Moore says:

    From my understanding of all I have, read, and studied and now believe. No matter what it is, if its been processed from its natural form, your body cannot recognize it. Anything it doesn’t recognize or doesn’t need or use, stores as fat, and has no health benefit and can actually be harmful in other way’s. If its a, whole food in its natural form. You reap all those benefits. NO, I would never drink milk or use milk products that came from a farm where all the cows are crowed spending their life eating feed given to them and standing in their poop all day and night forever, or, in a building where they stand day in and day out, just to be milked….Thats why they have to give them, antibiotics. When, cows or chickens or pigs, are free range, and graze, etc. depending on the animals, never given any chemicals, to grow faster or produce more, etc…you will have, healthy animals. The milk, the egss, your own homemade butter, from the milk fat, is off the charts good. Your body, recognizes what it is and uses it full of all the things your body needs. The only reason meat is bad for you is because all thats done to it before you ever get it.

  6. rex says:

    would love to see kefir made from raw milk on your next test

  7. Jo says:

    This helps explain why my children are allergic to supermarket milk but are able to eat yoghurt made from raw milk and also from unhomogenised milk produced at a local dairy which pasteurizes at the lowest temperature possible.

  8. Alison Lambert says:

    Wonderful study, thank you. I’ve been hearing for years that homogenised milk can penetrate the body’s cellular structures, into places where it can do damage. Would like to know the truth of this but it makes a kind of sense.
    Does nature approve??
    I drank milk still warm from the cow as a child but even then didn’t like it once it had stood and cooled off. Now, I’m lactose intolerant and rarely touch it except in tea or made into yogurt.

  9. Joy Crocker says:

    My raw milk kefir is way superior to kefir made with homog and past milk. Not science just my observation over the year of making it. Looks better tastes better grows faster fatter kefir grains.

  10. Gary Fox says:

    Had milk from the farmers pot and full of cream. Never had a problem with it and still don’t. Perhaps if kids went back to basics and just drank the real deal the health benefits would out weigh the junk made by science?

  11. James Cutcliffe says:

    Back in 2007 I was intrigued with the incredible health benefits I enjoyed from drinking raw milk which came from two biodynamic dairy farms. I persuaded a live blood analysis to have a look at raw milk and the various commercial milks, we did so at 400 magnification I also looked at the milk from a friend who was breast feeding she was consuming commercial full cream milk and then had the breast milk from the farmers wife who was also breast feeding and we were amazed at the difference, I also looked at kefr milk of various ages, next we looked at yoghurts made by various members of our sunshine coast group and noted the similarities, we extended the yoghurt inspection to commercial ones and noted the lack of life even in the the best organic ones on the market here on the coast, there were 45 test including whey, the final was to look at milk that had not been refrigerated at all for 190 days, it spent its life in its bottle unopened sitting in full sun on the barbecue this sample had wonderful life smelt sweet and was turned into a cheese and consumed by 27 people at a workshop, no one had any ill effects.
    I wonder how many WAPF members remember the article in our magazine that spoke of the Mongolian peoples that used a wooden bucket to contain their milk and the elder of the tribe stated the bucket had never been washed in her long lifetime
    I submitted a DVD of my slides in my 07 report and had the pleasure of spending time with Beverly Rubik in 2010 conference where she explained what I had recorded
    Raw milk from pastured cows saved my life and that began in 2001 after I had been informed by several medical professionals that my time had come
    I had also worked for the smallest of the major dairies and became aware of many of the rules that govern commercial dairy products and am amazed at how delebrit the deception is in the promotion of their products

    thanks for your time James Cutcliffe

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