We sent our grass-fed raw milk to a university lab. Here's how it compared.

🔵Miller's Bio Farm 100% Grass-Fed Raw A2/A2 Milk
Our cows eat nothing but pasture and what they forage in our biodiverse pastures, no grain, ever. They're A2/A2 tested, meaning they produce only the A2 beta-casein protein. The milk is raw, meaning it goes from the cow to the bottle without any heat treatment.

🔴 Local Farm Raw Grass/Grain Milk
Also raw, also A2/A2, but the cows are supplemented with grain. We included this because we wanted to show what diet does to the nutrient profile, independent of the raw vs. pasteurized question.

⚫ Grocery Brand Whole Grass Milk, Pasteurized
A well-regarded, widely available organic pasteurized milk. Grass-fed, certified organic, but heat-treated. We included this to give a fair pasteurized comparison that's also pasture-based.

Part 1: Fatty Acids

Fatty acids are where diet shows up most dramatically in milk. What a cow eats directly shapes the fat composition of her milk, and that fat composition has real implications for human health.

Omega-6 to Omega-3 Ratio

This is arguably the most important number in the whole report. The ratio of omega-6 to omega-3 fatty acids reflects the balance between pro-inflammatory and anti-inflammatory fats in the diet. A lower ratio is generally associated with better long-term health outcomes, lower risk of cardiovascular disease, chronic inflammation, and autoimmune disorders. Many researchers suggest an optimal ratio falls somewhere between 1:1 and 4:1.

Our milk came in at 1.03, right at the lower end of what researchers consider ideal. The grain-supplemented raw milk came in at 4.15, four times higher. This is the clearest illustration in the entire dataset of what grain feeding does to milk: it drives omega-6 levels up substantially, shifting the balance away from the anti-inflammatory profile that makes grass-fed dairy so compelling.

The grocery store milk edged us slightly on this metric, their ratio of 0.83 reflects consistent grass feeding even in a pasteurized product. We're sharing that because it's true, and because it reinforces the point: grass-fed diet matters, whether the milk is raw or pasteurized. But raw milk preserves other things that pasteurization cannot, and we'll get to that.

Omega Balance Score

The omega balance score measures the relative contribution of omega-3s compared to omega-6s, a higher score is better.

Lower omega-6 and a favorable omega-3 ratio together paint a consistent picture: 100% grass-fed diet produces a more balanced fatty acid profile.

Total Saturated Fatty Acids

Our milk came in close to the pasteurized option and well ahead of the grain-supplemented raw milk on protein. Worth noting: raw milk protein is also undenatured, meaning the amino acid structures remain intact and more bioavailable than heat-treated protein.

The pasteurized milk is notably higher in fat, likely a reflection of breed and seasonal variation rather than pasteurization itself. Our milk sits comfortably in the middle, with a nutrient-dense fat profile that reflects our pasture-based system.

Carbohydrates & Sugar

All three milks were nearly identical, right around 4.66g/100g of carbohydrates and sugar (naturally occurring lactose). No meaningful difference here.

Calorie differences track closely with fat content, as you'd expect.

Cholesterol

Our milk was notably higher in cholesterol, which, for most people following current nutritional science, is not a cause for concern. Dietary cholesterol is a precursor for steroid hormones, bile acids, and vitamin D, and its relationship with cardiovascular risk is far more nuanced than older guidelines suggested.

Part 3: Minerals

This is where our milk really shines. Across nearly every mineral measured, our 100% grass-fed raw milk came out ahead.

A few highlights worth calling out:

Calcium: Our milk delivered 143mg per 100g, that's 14% more than the pasteurized grocery store milk and 17% more than the local grass/grain milk. For a food that most people drink specifically for bone health, this is meaningful.

Phosphorus: 105mg vs. 83mg for the local farm grass/grain milk, a 26% difference. Phosphorus works alongside calcium in bone formation and is also critical for energy metabolism and DNA synthesis.

Sulfur: Our milk led with 35.4mg. Sulfur is a building block for glutathione, one of the body's most important endogenous antioxidants, as well as for cysteine and methionine, two essential amino acids.

Potassium and Iron: The two minerals where the pasteurized milk edged us out. We're sharing this because the full picture matters, and both are genuinely important nutrients.

Part 4: Heavy Metals

We know this isn't the most appetizing section of a food newsletter. But it matters, and the results are worth sharing.

All three milks came back at zero for lead, arsenic, cadmium, and nickel, the heavy metals of greatest concern from a human health standpoint. Barium was identical across all three and well below safe thresholds.

Aluminum was the one area where our milk registered higher than the other two at 0.18mg/100g. It's worth noting that all values across all three milks fall well within the safe tolerable weekly intake established by food safety authorities (1mg/kg body weight/week), and aluminum is naturally present in soil and water at varying levels depending on geography. We flag it here because transparency means sharing everything, not just the numbers that flatter us.

Part 5: Phenolics & Carotenoids; The Lutein Finding

This was the most unexpected result in the entire report, and honestly the one we've been most eager to share.

The lab tested all three milks for a comprehensive panel of phenolic compounds and carotenoids, the antioxidant pigments associated with everything from eye health to cancer protection. Most came back at zero across all three milks, which is typical for dairy. But lutein told a very different story.

Both raw milks, ours and the local farm's showed meaningful levels of lutein. The pasteurized milk had none.

Lutein is a carotenoid well known for its role in eye health. It concentrates in the macula of the eye, where it filters harmful blue light and is associated with reduced risk of macular degeneration and cataracts. It's heat-sensitive, and pasteurization appears to have eliminated it entirely from the grocery store milk.

This is one of those findings that's hard to argue with. It's not about raw milk being dangerous or safe. It's about what heat does to a specific, beneficial compound. The lutein was there in the raw milk. It wasn't in the pasteurized milk. That's the data.

What It All Means

We set out to do an honest comparison, and that's what we got. Here's our plain-language summary:

100% grass-fed diet is the single biggest variable. The gap between our milk and the grain-supplemented raw milk, especially in the omega fatty acid profile, is striking. They're both raw. They're both A2/A2. The difference is what those cows ate. Pasture produces a more balanced, more anti-inflammatory fat profile. Full stop.

Raw milk preserves what pasteurization cannot. The lutein finding is the clearest example. Pasteurization is effective at reducing bacterial risk, but it also eliminates heat-sensitive nutrients. Whether that tradeoff is worth it is a personal decision, and we respect that. But you should know the tradeoff exists.

Our mineral density reflects our soil. Healthy pasture, managed regeneratively, produces mineral-rich forage. That forage becomes mineral-rich milk. The calcium, phosphorus, magnesium, and sulfur numbers reflect what happens when you take soil health seriously.

Transparency is non-negotiable for us. We shared every number in this report, including the ones where we didn't come out on top. Because that's what it means to actually be honest with the people who feed their families our food.

We'll continue testing. We'll continue sharing. And we'll continue doing the thing that makes all of this possible: keeping our cows on pasture, where they belong. 

What are your thoughts on this testing? 

All testing conducted by the Center of Human Nutrition Studies Lab at Utah State University, May 2026. Results reflect samples collected in May 2026 and are representative of that testing period.