Traditionally, buttermilk was a beverage made from liquid created when cream was churned into butter. These days, most buttermilk is made from milk and is used in baking, such as biscuits and pancakes. If you’re a baker, you may be wondering if buttermilk is a FODMAP safe ingredient. It’s really not, but there’s an easy workaround.
Buttermilk is not low FODMAP. A cup of cultured buttermilk, made from milk, contains around 9 grams of lactose. A cup of traditional buttermilk, made from cream, contains about 12 grams of lactose. Both of these amounts exceed suggested low FODMAP guidelines for lactose intake.
In this post, we’ll look at the three common types of buttermilk and how the process of making each affects lactose content. Then we’ll look in more detail at cultured buttermilk, the kind typically sold in grocery stores. The presence of bacterial cultures in cultured buttermilk results in a lower lactose content than that in regular milk.
Types of Buttermilk
Note: all links in this post open in a new tab, unless otherwise stated. To learn more about how research for this site is conducted, please visit the data and methods page.
The amount of lactose in buttermilk varies depending on how its made. Traditional buttermilk, made from cream, has fairly high levels of lactose. However, this isn’t the kind of buttermilk you’ll typically find in grocery stores.
Instead, most commercially produced buttermilk is cultured buttermilk. This is made from milk, not cream, and actually has lower lactose levels. We’ll learn why that is, then briefly look at acidified buttermilk, often made by home cooks.
Traditionally, buttermilk was made from cream, not from milk. You can learn more about this process in my post on butter, but here’s a quick summary.
In the past, milk was allowed to rest long enough for fat in the milk to separate and rise to the top. This thick, liquid fat is better known as cream. When cream separates from milk, much of the lactose is left behind in the liquid portion of the milk. As a result, cream has significantly less lactose than milk.
Once the cream was removed from the milk, it was churned. During churning, the fats in the cream clumped together, creating butter. So, after the churning process, there were two products: the solid butter and the leftover liquid. This leftover liquid is known as buttermilk.
FODMAPs, like lactose, are water soluble carbohydrates. This means they dissolve and remain in liquid, but not in solids, like fat. The result is that butter, which is nearly 100% fat, has very little lactose, while buttermilk has quite a lot. But this also means traditionally made buttermilk is naturally low in fat.
Most buttermilk for sale in grocery stores is not made this traditional way. In fact, the only cream-based buttermilk I could find is from a company called Kate’s Butter. Most buttermilk sold in stores is made from milk, not cream. This commercially produced buttermilk is often labeled “cultured buttermilk.”
These days, manufacturers make buttermilk by adding bacteria to milk. Because of this, buttermilk is considered a fermented dairy product, like yogurt and kefir. It’s often referred to as cultured buttermilk, owing to the bacterial cultures.
Bacteria used to create buttermilk include Lactococcus lactis and Lactobacillus bulgaricus, which are often found in yogurt and kefir, too. The bacteria breaks down lactose, turning it into lactic acid. This acid is what gives buttermilk it’s tangy taste. It also causes the proteins in the milk to solidify, which is why buttermilk is thicker than regular milk.1
The breakdown of lactose means buttermilk has less lactose than regular milk. We’ll look at a comparison in a bit.
Many home cooks make a quick, substitute version of buttermilk by adding an acidic ingredient to regular milk. Typical ingredients are vinegar, lemon juice and cream of tartar, which is a weak form of tartaric acid. This simple mix is known as acidified buttermilk.
The acid in the milk acts similarly to the bacteria used in making cultured buttermilk. The acid provides a tangy taste like that of real buttermilk. And the acid also causes the milk proteins to thicken, giving acidified milk the thicker texture of buttermilk.2
However, acids like vinegar and lemon juice don’t have the bacteria needed to breakdown lactose. So, unlike cultured buttermilk, acidified milk contains the same amount of lactose as regular milk.
FODMAPs in Buttermilk
Lactose is the only known FODMAP in buttermilk. However, the lactose content varies, depending on whether the buttermilk is made from cream or milk.
FODMAPs in Traditional Buttermilk
As mentioned earlier, the only buttermilk I could find that’s made from cream is Kate’s Buttermilk. The Kate’s website lists the carbohydrate content of one cup of buttermilk as 12 grams. As I wrote in my post on FODMAPS in milk, lactose is the primary carbohydrate in milk. So, we can estimate that one cup of cream-based buttermilk has about 12 grams of lactose.
This is the same amount of lactose as in a cup of regular, whole milk. I know this may be confusing. You might have read that buttermilk has less lactose than regular milk. And heavy cream, from which buttermilk is made, has about half the lactose of regular milk. So, how does a cup of traditional buttermilk end up with as much lactose as regular milk?
Heavy cream is about 85% fat. This fat is used to make butter. When fat is removed from cream to make butter, most of the volume is removed, too. What’s left behind is the liquid buttermilk. Because the volume decreases so much when the fat is removed, it actually takes about two cups of heavy cream to produce one cup of buttermilk.
Since a cup of heavy cream contains between 6 and 7 grams of lactose, two cups will contain 12-14 grams of lactose. And, unlike cultured buttermilk, there’s no acid to help breakdown the lactose. This is why a cup buttermilk made the traditional way has about the same of lactose as a cup of milk.
FODMAPs in Cultured Buttermilk
The breakdown of lactose within cultured buttermilk reduces the total lactose content by about 25%, when compared to regular milk. As with regular milk, the lactose content varies slightly based on fat content. But in general, a cup of buttermilk contains about 9 grams of lactose, while a cup of regular milk contains about 12 grams.
The following table shows the lactose content of buttermilk and regular milk at different fat levels. For reference, whole milk has a fat content of 3.25%. Reduced fat has 2% fat, while lowfat has 1% fat. Skim milk is considered fat free.
Lactose Content in Milk versus Buttermilk (in grams)
As shown in the table, while cultured buttermilk contains less lactose than regular milk, it still contains a significant amount of lactose. The lactose levels found in buttermilk far exceed those recommended by low FODMAP researchers. They suggest limiting lactose to no more than one gram per serving.5 As the table suggests, one serving of cultured buttermilk contains nine times the suggested amount.
FODMAP Friendly Buttermilk?
Buttermilk isn’t as popular as other dairy products and consumption of buttermilk has slowly declined since the mid-20th century.6 Unsurprisingly, then, major dairy manufacturers don’t make lactose-free, FODMAP friendly buttermilk. I was unable to find any major milk brand that produces lactose-free buttermilk.
If you require lactose-free buttermilk, your best option seems to be making your own acidified buttermilk. You can do this by adding one tablespoon of vinegar or lemon juice to one cup of lactose-free milk. Let it sit 10 minutes to allow the acid to thicken the milk.
Conclusion: Buttermilk is a High FODMAP Food
Regardless of the type of buttermilk you buy, it’s likely high FODMAP. Traditional buttermilk made from cream is hard to find in stores and has a lactose content similar to that of milk. Cultured buttermilk is more common and has about 25% less lactose than regular milk, but is still too high in lactose to qualify as low FODMAP.
The only exception here is buttermilk made from lactose-free dairy milk or from a plant-based milk. However, I’ve never seen lactose-free dairy based buttermilk or vegan (plant-based) buttermilk in grocery stores. If you need lactose-free buttermilk, your best option may be to make your own using a simple recipe for acidified buttermilk.
Posts Related to “Is Buttermilk Low FODMAP?”
All dairy products start with milk, so it’s worth knowing more about the lactose content of milk, to understand how processing it into other products increases or decreases the FODMAP content.
And if you want to learn more about buttermilk’s origins as a dairy byproduct, check out my post on how (and why) butter is low FODMAP.
If you don’t want to cook with dairy milk at all, you can use almond milk instead. As I’ve described in another post, almond milk is a low FODMAP milk alternative. You can make acidified almond milk to substitute for buttermilk, similar to the process described earlier.
About the Author
Amanda Coleman, PhD, studies food culture and teaches a popular Food and Society course. Years of digestive problems led her to live low FODMAP. Now she uses her research and analysis skills to help others understand FODMAP essentials, so they can lead better, healthier lives.