My Experience With Switching From Pasteurized Milk to Raw Milk
My Experience With Switching From Pasteurized Milk to Raw Milk
Introduction
I’ve been drinking pasteurized milk for basically my entire life. Before I started this experiment, I usually drank around 250 mL of milk at night.
On 8 July 2026, I decided to try something different. I switched from pasteurized milk to raw cow’s milk, and at the same time I increased the amount I was drinking quite a lot.
Instead of around 250 mL a day, I started drinking roughly 1 litre every day.
I started writing this on 19 August 2026, so by this point I had been doing it for more than a month and had enough time to notice some changes.
Right now, my routine is roughly:
- 500 mL in the morning after waking up
- 500 mL in the evening
I haven’t intentionally changed much else. My sleep, hydration, exercise, and normal routine have stayed fairly similar.
So from my point of view, the biggest change has been the milk.
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How I Started
When I first started, I would drink the milk shortly after it was taken from the cow.
There wasn't really a waiting period.
More recently, I started leaving it out for around 30–45 minutes before drinking it. I’m doing this because I want to document what happens when the milk spends some time at room temperature.
I know that this doesn't make the milk safer. If anything, I understand that leaving raw milk out can give bacteria more opportunity to multiply.
I'm aware that I'm taking a risk by doing this.
I'm also not saying that because I haven't gotten sick, the milk must be safe. I haven't actually tested the milk for pathogens, so I have no way of knowing exactly what is or isn't in it.
I'm simply recording what I've been doing and what I've experienced.
At the beginning:
Milking → drink shortly afterward
More recently:
Milking → leave for around 30–45 minutes → drink
This is part of my personal experiment, not something I'm recommending other people do.
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The First Few Weeks
The beginning wasn't exactly pleasant.
When I suddenly went from drinking around 250 mL of milk a day to around 1 litre, my stomach definitely noticed.
I started experiencing:
- Loose stools
- Bloating
- A heavy feeling in my stomach
- Nausea
- Feeling like I might throw up
I was also going to the bathroom roughly four times a day.
At first, I wasn't sure what was causing it.
The obvious thing that stood out was the amount of milk. I had basically increased my intake four times over almost immediately.
So I think the sudden increase could have had something to do with it.
I can't prove that, though.
If I were starting over, I'd probably increase the amount slowly instead of jumping straight from 250 mL to 1 litre.
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My Stomach Eventually Got Used to It
The strange thing is that the problems didn't last forever.
Over the next few weeks, things slowly got better.
The loose stools eventually stopped.
The bloating went away.
The nausea disappeared.
The heavy feeling in my stomach became much less noticeable.
After roughly a month, I reached the point where I could drink the milk without feeling like my stomach was fighting me.
My bowel movements also changed.
At the beginning, I was going around four times a day.
Now it's roughly twice a day.
I honestly don't know why that changed. It could be related to the milk, the amount I’m drinking, my diet, or something else entirely.
So I don't want to make it sound like I discovered some definite effect of raw milk.
What actually happened was much simpler:
I started drinking a lot more milk, had digestive problems for a while, and eventually my stomach seemed to handle it much better.
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Drinking It Slowly Seems to Help
One small thing I've noticed is that the speed at which I drink the milk seems to make a difference.
If I drink a large amount quickly, my stomach feels much heavier afterward.
If I take my time and slowly drink it, I generally feel more comfortable.
Because of that, I prefer drinking the 500 mL slowly rather than finishing it all at once.
That's just something I've noticed about myself. I don't know if it would be the same for somebody else.
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Energy, Strength and Weight
The biggest positive change I've noticed is how I feel physically.
Before the experiment, I would have rated my energy around 6/10.
Now I'd put it around 8/10.
For strength, I previously would have said around 4.5/10.
Now I'd say roughly 8.5/10.
My weight also went from around 54 kg to 56 kg.
But there's an obvious problem with trying to blame all of that on raw milk.
I didn't just change the type of milk.
I also went from around 250 mL to around 1 litre every day.
That's a huge increase.
I'm getting significantly more calories, protein, fat, carbohydrates and other nutrients from milk than I was before.
So I can't honestly say:
"Raw milk made me stronger."
It could have been the extra calories.
It could have been the extra nutrients.
It could have been the increase in milk itself.
It could have been the change from pasteurized to raw.
It could have been a combination.
There could also be something completely unrelated that I haven't noticed.
All I can really say is that after making the change, I noticed that I felt more energetic and stronger, and my weight went up.
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What About Salmonella, E. coli and Other Bacteria?
This is probably the part of the experiment that interests me the most.
I've seen people make completely opposite claims about raw milk.
Some people say the dangers are exaggerated.
Other people point toward organisms such as Salmonella, E. coli, Campylobacter, and Listeria and say that raw milk can be dangerous.
I don't want to automatically believe either side.
I want to actually understand what's going on.
For example, I want to know:
- How often raw milk becomes contaminated
- What organisms are actually found in contaminated samples
- How contamination happens
- How much the animal itself matters
- How much milking hygiene matters
- How temperature affects the milk
- How much time matters
- Whether contamination varies dramatically between batches
- What pasteurization actually changes
- What laboratory tests can and cannot tell us
The fact that I haven't gotten sick doesn't answer any of those questions.
It only tells me that I haven't noticed an illness so far.
That's a very different thing.
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The 30–45 Minute Waiting Period
The waiting period is one of the more unusual parts of what I'm doing.
I'm deliberately recording the fact that the milk sometimes sits out for around 30–45 minutes before I drink it.
I'm interested in what happens during that period.
But I don't want to make the mistake of assuming that because nothing happens that I can see, nothing is happening microscopically.
That's actually one of the reasons I'd eventually like to use proper testing.
Milk can look completely normal while microorganisms are present.
I also understand that intentionally leaving raw milk out isn't a safe storage method. If I were doing a proper food-safety study, I would want the temperature and time to be measured and the samples to be handled according to appropriate laboratory procedures.
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What Has Stayed the Same?
I've tried to keep the rest of my routine fairly normal.
I haven't intentionally changed:
- Sleep
- Hydration
- Exercise
- General lifestyle
- Normal daily routine
Obviously, I can't control everything.
I'm still a person living a normal life, not someone sitting inside a laboratory where every variable is controlled.
My diet can change slightly from day to day.
My sleep can vary.
My exercise can vary.
My stress can vary.
So I know this isn't a perfect experiment.
The main intentional change was the milk.
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What I've Observed So Far
As of 19 August 2026:
- I started on 8 July 2026.
- I switched from approximately 250 mL of pasteurized milk to around 1 litre of raw milk per day.
- My weight went from roughly 54 kg to 56 kg.
- I initially had loose stools, bloating, nausea and stomach heaviness.
- I was initially having bowel movements around four times a day.
- Those digestive problems gradually improved over roughly a month.
- I'm now going around twice a day.
- Drinking the milk slowly seems more comfortable for me.
- My self-rated energy went from about 6/10 to 8/10.
- My self-rated strength went from about 4.5/10 to 8.5/10.
- At first I drank the milk shortly after milking.
- More recently, I've been leaving it out for roughly 30–45 minutes before drinking it.
- I haven't noticed an obvious illness that I've attributed to the milk.
That's basically where things stand.
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What I Still Don't Know
There's actually a lot I don't know.
I don't know whether raw milk itself had anything to do with the increase in my energy.
I don't know whether my strength improved because of raw milk or because I started consuming much more food and calories through the extra milk.
I don't know exactly what caused my initial digestive problems.
I don't know why my bowel movements went from roughly four times a day to around two.
I don't know how much of my weight gain came from the milk.
And I definitely don't know what's happening microbiologically inside the milk.
That's probably the biggest unanswered question.
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What I Want to Do Next
At the moment, most of my experiment is based on observation.
I'd like to move beyond that.
If I can get access to the right equipment, laboratory services and information, I'd like to start collecting actual measurements.
I want to be able to look back at the data and say:
"This is what happened,"
rather than:
"I think this is what happened."
- Test the Milk for Microorganisms
The biggest thing I'd like to investigate is the microbiological side.
I'd want professional laboratory testing for organisms such as Salmonella, pathogenic E. coli, Campylobacter and Listeria, along with appropriate indicator tests.
I wouldn't want to rely on a microscope alone for this.
A microscope can show things such as cells, particles or microorganisms that are large enough to be observed, but it generally cannot tell me reliably whether a particular bacterium is a dangerous pathogen.
For that, I'd want proper laboratory methods.
Depending on the laboratory and the question being asked, that could include methods such as:
- Culture-based identification performed by qualified laboratories
- PCR-based testing
- Quantitative PCR where appropriate
- Other molecular detection methods
- Appropriate biochemical or molecular identification
- Microbial enumeration or indicator testing
PCR especially interests me because it can detect genetic material from specific organisms.
However, PCR results also need to be interpreted properly. Detecting DNA doesn't necessarily mean that a particular organism is alive or capable of causing disease.
That's another reason I'd want the testing done by a qualified laboratory rather than trying to interpret everything myself.
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- Microscope and Microscopy Equipment
If I eventually get into the microscopy side of the project, I'd want equipment such as:
- A good-quality compound microscope
- Appropriate objective lenses
- Microscope slides
- Coverslips
- Slide storage boxes
- Appropriate sample containers
- Pipettes and suitable laboratory consumables
- Disposable gloves
- Protective eyewear where appropriate
- A phone or camera adapter for photographing what I see
- Basic cleaning supplies for the microscope
A microscope could be useful for observing the general structure and contents of milk samples.
It could potentially allow me to compare samples visually and document differences.
But I wouldn't use microscopy as proof that the milk is free of dangerous bacteria. A normal-looking microscopic sample doesn't mean a sample is pathogen-free.
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- Temperature and Time Measurements
For the part of the experiment involving storage and the 30–45 minute period, I'd want much better measurements.
Useful equipment would include:
- Accurate digital thermometer
- Refrigerator thermometer
- Temperature data logger
- Timer
- Measuring cylinder or graduated container
- Accurate weighing scale
- Clean food-grade sample containers
- Labels and permanent markers
A temperature data logger would be particularly useful because instead of checking the temperature once, it could record changes over time.
That would let me keep track of things like:
Milking → refrigeration → removal from refrigeration → room-temperature period → consumption
with actual times and temperatures.
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- Sample Tracking
If I eventually start sending samples to a laboratory, I'd need a proper way to keep track of them.
Each sample could have information such as:
- Sample number
- Date
- Time collected
- Source
- Time refrigeration started
- Storage temperature
- Time removed from refrigeration
- Temperature at sampling
- Time sent to laboratory
- Test requested
- Laboratory result
I'd also want to keep a separate research log so I don't accidentally mix up samples or forget what happened to a particular one.
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- Nutritional Testing
Another thing I'd like to investigate is the actual nutritional composition of the milk.
Instead of assuming that raw milk has a particular nutritional profile, I'd like to know what the milk I'm actually consuming contains.
Depending on what testing is available, useful measurements could include:
- Protein
- Fat
- Carbohydrates
- Energy
- Total solids
- Other relevant nutritional components
I'd also want to compare this with the nutritional information for the pasteurized milk I used to drink.
This would help answer an important question:
Did I actually change the nutritional composition of my diet, or did I mainly change the way the milk was processed?
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- Body and Exercise Measurements
I also want to get better at measuring the changes in my own body.
I'd like to track:
- Body weight
- Energy
- Strength
- Exercise performance
- Sleep
- Milk intake
- Total food intake
- Bowel movements
- Stool consistency
- Bloating
- Nausea
- Other digestive symptoms
Some of these are subjective, but I can at least make the way I record them consistent.
For example, instead of randomly deciding what my energy feels like each day, I could record it at the same time every day using the same 1–10 scale.
For exercise, I could record actual performance rather than just saying that I feel stronger.
That would give me something more concrete to compare.
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- Data Analysis
Once I have enough information, I'd like to put everything into a spreadsheet.
I could then make graphs showing things like:
- Weight over time
- Milk intake over time
- Digestive symptoms over time
- Energy over time
- Strength over time
- Sleep compared with energy
- Exercise performance compared with milk intake
- Temperature and storage time alongside laboratory results
This would make it much easier to see whether something is actually changing or whether I'm just remembering the unusual days.
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- Proper Scientific Resources
Equipment isn't enough.
I'd also need good information.
I'd want access to:
- Peer-reviewed research papers
- Dairy-science research
- Food microbiology textbooks
- Food-safety guidelines
- Government food-safety information
- Public-health resources
- Laboratory testing standards
- Scientific databases
- Nutritional databases
I'd also want to learn how to read scientific papers properly.
If I find a study saying that raw milk contains a particular pathogen, I want to know how the researchers collected the samples, how many samples they tested, what testing method they used, and what the limitations were.
Otherwise, it's very easy to take one number from a study and misunderstand what it actually means.
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- Laboratory Access
This is probably more important than buying a huge amount of equipment myself.
For the microbiological part, I'd rather work with a properly equipped laboratory than try to culture unknown microorganisms at home.
Some of the things I'd want access to through a qualified laboratory include:
- PCR testing
- Microbiological analysis
- Pathogen screening
- Quantitative microbial testing where appropriate
- Professional sample preparation
- Proper controls
- Sterile laboratory equipment
- Appropriate incubators and analytical instruments
- Identification methods
- Professional interpretation of results
There are many pieces of laboratory equipment that I don't necessarily need to own personally.
It would make much more sense to have a professional laboratory perform tests that involve potentially dangerous microorganisms.
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- Other Laboratory Equipment I'd Like to Understand
If I eventually get more involved in laboratory science, there are a lot of instruments I'd like to learn about.
For example:
- Compound microscope
- Digital microscope camera
- Micropipettes
- Centrifuge
- Spectrophotometer
- PCR equipment
- Real-time PCR equipment
- Analytical balance
- pH meter
- Temperature data logger
- Refrigerator/freezer suitable for laboratory samples
- Appropriate sample storage equipment
There are also more advanced instruments used in professional microbiology and food science.
I don't necessarily need all of these for my personal project. Some would be unnecessary or far too expensive.
The point is to understand which instrument answers which question and use the appropriate professional service when I don't have the equipment or facilities myself.
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- Safety Equipment
Because raw milk can potentially contain harmful microorganisms, safety equipment matters too.
Depending on what I'm doing, that could include:
- Disposable gloves
- Protective eyewear
- Laboratory coat
- Appropriate cleaning and disinfection supplies
- Proper waste containers
- Food-safe sample containers
- Clearly labeled samples
- Safe refrigeration and transport arrangements
I would especially avoid attempting to culture unknown organisms myself.
There's a big difference between observing a sample under a microscope and trying to grow microorganisms from a sample.
The second can potentially increase exposure to pathogens and is something I'd leave to an appropriately equipped laboratory.
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A Better Version of the Experiment
If I were eventually able to restart the experiment properly, I'd want to make it much more controlled.
The biggest problem with my current experiment is that I changed two things at once.
I went from:
250 mL pasteurized milk
to:
1 litre raw milk
So if something changes, I can't tell which variable caused it.
A better experiment would keep as many things as possible consistent and change one variable at a time.
I'd also record everything rather than relying on memory.
That would include milk intake, body weight, food intake, sleep, exercise, symptoms, temperature, storage time and laboratory results.
Even then, it wouldn't be a perfect scientific study.
One person isn't enough to establish what happens to everyone.
But it would still be much better than simply drinking the milk and deciding that whatever I feel must have been caused by it.
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Final Thoughts
This experiment started as a pretty simple change.
I went from drinking around 250 mL of pasteurized milk every day to drinking around 1 litre of raw milk.
The first few weeks weren't great. My stomach reacted badly, I was going to the bathroom more often, and I had bloating and nausea.
Eventually, things settled down.
Now I feel like my stomach handles the milk much better. I've also noticed an increase in my energy and strength, and my weight has gone from around 54 kg to 56 kg.
But I don't want to jump to conclusions.
The biggest problem is that I changed the amount of milk at the same time as changing the type of milk.
So I can't honestly say that raw milk caused the changes.
As of 19 August 2026, that's where the experiment stands.
I've noticed some real changes in my own experience, but I still have a lot of unanswered questions.
And honestly, that's probably the most interesting part of the whole thing.