What is A2 versus A1?

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July 17, 2025

What is A2 milk?

Let’s talk science for a minute

All mammals produce milk, which naturally contains fats, carbohydrates, and proteins. The proteins in milk are mainly of two types: whey and casein.

What’s the Deal with Casein in Milk?

If you've ever looked into the components of milk, you’ve probably come across casein—a major milk protein.

In fact, casein makes up about 80% of the protein in cow’s milk. Within casein, there are several sub-types, and one of the most important is called beta-casein, which accounts for roughly 30% of the total protein.

Now, here’s where it gets interesting.

Not All Beta-Casein Is the Same

There are two main forms of beta-casein: A1 and A2. The difference between them comes down to a small genetic variation—but that small change can affect how the protein is digested in the body.

Here’s the fascinating part:

Almost every mammal species on the planet naturally produces only the A2 type of beta-casein.

Goats, sheep, camels, even humans—all A2.

Except Cows. Yes, Cows!

Due to genetic variation in modern dairy herds, many cows—especially Holsteins—produce a mix of A1 and A2 beta-casein, or in some cases, only A1. This makes cows the only mammals known to naturally produce A1 beta-casein.

Digestion and the Release of BCM-7

When you digest A1 β-casein, your body may release a compound called β-casomorphin-7 (BCM-7)—a peptide that has drawn attention in health research.

BCM-7 is a bioactive peptide, meaning it can interact with the body in various ways. It’s classified as an opioid peptide, which means it can bind to opioid receptors in the body, potentially affecting things like:

Gut motility
Inflammatory response
Immune function
Neurological activity

On the other hand, A2 β-casein is digested differently. Because of its slightly altered protein structure, A2 milk is far less likely to release BCM-7 during digestion (Sodhi, Monika et al.)

Why This Matters

Most store-bought milk in the U.S. comes from cows that produce a mix of A1 and A2 proteins—or only A1. That means BCM-7 may be released when drinking conventional milk.

Some people with mild dairy sensitivities report fewer digestive issues when switching to A2-only milk, with research suggesting that BCM-7, not lactose is the culprit behind digesting cow’s milk, though research is ongoing. The key takeaway: that one small difference in the protein structure may influence how milk behaves in the body.

Where we stand

At Countryside Mercantile, the milk is sourced from Guernsey cows, which are distinguished not only by their A2/A2 genetic profile but also by their production of a diverse range of milk components. A detailed discussion of these qualities will be reserved for a future article.

References

Sodhi, Monika, et al. “Milk Proteins and Human Health: A1/A2 Milk Hypothesis : Indian Journal of Endocrinology and Metabolism.” IJEM, Sept. 2012, journals.lww.com/indjem/fulltext/2012/16050/milk_proteins_and_human_health__a1_a2_milk.37.aspx.

A1, A2, beta casein, BCM-7, digestion, raw milk, cows

What To Do When You Have Too Much Raw Milk

I was visiting with a friend the other day about milk — how some weeks it seems to disappear faster than we can blink, and other times it ends up sitting in the fridge longer than we’d like. 🥛 When it comes to raw milk, every drop feels precious. It’s the good stuff — straight from the farm, and in my perspective, a lot of work— and the last thing I ever want to do is let it go to waste. So here are some things I do when I need to use up some extra milk. Hot Chocolate or Latte’s Something about the colder months just calls for a warm drink in hand — a cozy cup of hot chocolate, or a creamy coffee or tea latte made with fresh milk. ☕️ And when summer rolls around, an iced tea latte hits the spot just right — cool, refreshing, and a whole lot better than most of those sugary summer drinks. Easy Hot Chocolate Recipe 1 cup raw milk 1 TBSP raw cacao 1 TBSP honey or maple syrup 1. Heat milk with a coffee frother or on the stove.2. Once at desired temp, add the cacao and the honey (maple syrup) to taste.3. Mix or whip until combined Tea Latte 1 tea packet or loose leaf tea of choice ½ cup water (can use less depending on cup size) ½ cup raw milk (can use less or more depending on cup size) 1-2 TBSP honey or maple syrup 1. Heat water and steep desired tea.2. Add tea to a cup with honey or maple syrup.3. Froth the milk and add to tea. Waffles I never realized how much milk a batch of waffles can take until I started making them for my boys. Around here, waffles disappear faster than I can stack them! 🧇 So now, on slower mornings, I mix up a big bowl of batter with our fresh raw milk and cook them up by the dozen. Once they’re cooled, I tuck them into the freezer—ready for those busy mornings when chores are calling and hungry boys come running. Nothing fancy, just good, wholesome food made from the milk our cows worked hard to give us. The recipe provided is courtesy of Thankfulhomemaking.com, however, multiple waffle recipes work as they all tend to use a good amount of milk. Butter Milk Waffles 2 cups flour 2 TBSP sugar 2 tsp baking powder 1 tsp baking soda ½ tsp salt 2 ½ cups butter milk – (to make butter milk add 2.5 TBSP vinegar or lemon juice to the milk) 1/3 cup butter, melted 2 eggs 1 tsp vanilla 1. In a large bowl, mix together the buttermilk and melted butter. Add the eggs and vanilla and mix well. In another bowl, whisk together flour, sugar, baking powder, baking soda, and salt. 2. Add dry ingredients to the wet ingredients and whisk until just combined. Then let batter rest while you preheat your waffle iron. 3. Pour batter into waffle iron and cook until ready 4. Extras can be frozen nicely for later use. Yogurt Yogurt is one of our favorite ways to put extra milk to good use. It’s simple, wholesome, and so versatile — perfect as a base for smoothies, a stand-in for sour cream in recipes, or just enjoyed on its own with a drizzle of honey and a handful of fresh fruit. There’s something special about that creamy, homemade goodness straight from your own milk supply. 🥛🍯 There are multiple ways that yogurt can be made and simply without any special kitchen appliances, however, one of my favorite recipes includes the use of an insta pot and is fool proof. Recipe courtesy of FarmHouseOnBoone.com Yogurt ½ gallon whole milk (raw in this case) ¼ cup yogurt culture or plain yogurt 1. Pour the ½ gallon of milk in the insta pot and press the “saute” button. Heat the milk to 180 while whisking constantly.2. Once the milk reaches 180, turn off “saute” option and allow milk to cool back down to 115.3. Add in ¼ cup of plain yogurt or starter culture and whisk into milk.4. Set insta pot for 8-24 hours on the yogurt setting. 5. Once the timer goes off you can transfer the yogurt to a container and chill or to make a little thicker, strain in a cheese cloth for up to an hour. Smoothies Without a doubt, smoothies are one of the easiest (though not always the tidiest!) ways to use up extra milk — especially when you’re blending for a crowd of hungry kids. The best part? The flavor possibilities are endless. Here are a few of our family’s favorite go-to smoothie combinations that never fail to please. 🥛🍓🍌 Chocolate Peanut Butter Smoothie 1 cup whole raw milk ½ cup raw milk yogurt (or plain regular yogurt) ¼ cup peanut butter 1 frozen banana 1 TBSP cacao powder 1. Place all ingredients in a blender.2. Blend until smooth and incorporated.3. Transfer to a cup to enjoy. Berry Smoothie 1 cup whole raw milk ½ cup raw milk yogurt (or plain regular yogurt) ½ cup frozen berries of choice 1 frozen banana 1 TBSP chia seeds, flax seed, hemp seed or whatever you may like 1. Place all ingredients in a blender.2. Blend until smooth and incorporated.3. Transfer to a cup to enjoy. I know there are a hundred other ways to put that extra milk to good use, but we’ll stop here for today. Maybe in the next blog, we’ll chat about soups and cream bases — perfect ways to keep every drop of that milk working for you. Until then, if you’ve got a little extra in the fridge, give one of these ideas a try and keep that precious raw milk from going to waste. 🥛✨

Let’s Talk About Freshness: Why Raw Milk Isn’t Meant to Last Forever

Raw milk is a living, fresh food, not meant to sit in the fridge for months like processed dairy. Just like fresh raspberries, it’s natural for raw milk to change over time. When it starts to sour after a week or two, that doesn’t mean it’s “bad”—it’s simply evolving as nature intended. Unlike pasteurized milk, which spoils and molds, raw milk ferments safely thanks to its natural enzymes and beneficial bacteria. This souring process can even create delicious new products like clabbered milk, sour cream, or homemade cheese. To enjoy it at its best, drink raw milk within 7–10 days of purchase and store it properly: Keep it in the coldest part of the fridge (not the door). Always seal the lid tightly to slow souring. Avoid transferring it into new containers to prevent contamination. Raw milk doesn’t “expire”—it transforms. Embrace its freshness, flavor, and life-giving qualities by enjoying it close to the source—straight from the farm, the way nature intended.

What To Do With Raw Milk Cream?

Raw milk cream is one of the richest, most versatile parts of farm-fresh milk — perfect for everything from sweet treats to nourishing everyday meals. Its natural flavor and nutrients make it a staple in any traditional kitchen. You can turn raw cream into indulgent desserts like homemade ice cream, whipped cream, or butter, or use it in everyday ways such as coffee creamer, oatmeal, or smoothies. In the kitchen, raw cream adds richness to sauces, soups, baked goods, and cultured creations like sour cream, clotted cream, or European-style cultured butter. For convenience, raw cream freezes well, though fresh cream makes the best butter. ✨ Whether whipped, churned, or cultured, raw milk cream is a wholesome, flavorful ingredient that brings old-fashioned goodness to modern kitchens.

What is A2 versus A1?

More from the blog

What To Do When You Have Too Much Raw Milk

Let’s Talk About Freshness: Why Raw Milk Isn’t Meant to Last Forever

What To Do With Raw Milk Cream?

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