What is buttermilk? Definition, benefits, uses, and differences

What is buttermilk ? It is a fermented milk (a Breton specialty) with a fluid texture and a slightly tangy taste, obtained by lactic fermentation (and sometimes likened to buttermilk depending on the country/recipe).

• more digestible for many people (lactose partially consumed by fermentation)
• tangy flavor that can replace yogurt or lemon in cooking
• ideal texture for pancakes, crepes, fluffy cakes
• interesting for varying fermented foods on a daily basis
• often lighter than cream in some preparations

In practical terms, buttermilk serves both as a fermented beverage and as a "technical" ingredient: it provides acidity, creaminess, and natural fermentation. Here's the gist, without the jargon.

Buttermilk: a simple definition (and why it's called "fermented")

Buttermilk is fermented milk : lactic acid bacteria (beneficial bacteria from the lactobacillus/streptococcus family, depending on the strain) are added, which transform some of the lactose into lactic acid. This acidification:

• gives it a slightly tangy taste
• thickens the texture slightly
• may improve digestive tolerance in some people.

Not to be confused with “turned” milk: here, fermentation is controlled and desired.

Origin: a Breton specialty (and its cousin “buttermilk”)

Traditionally in Brittany, buttermilk is linked to rural customs and the value placed on milk. In Anglo-Saxon culture, the term "buttermilk" is often encountered. Depending on the context, "buttermilk" can refer to:

• the liquid remaining after churning the butter (traditional version),
• or a fermented milk “buttermilk type” (the most common modern version in stores).

In practice, in France, lait ribot = fermented milk sold as such. In translated recipes, “buttermilk” generally refers to a tangy fermented milk (similar to ribot), but not always strictly identical.

Taste, texture, shelf life: what to expect

• Taste : mild, slightly tangy (less acidic than a highly fermented kefir, often milder than plain yogurt).
• Texture : fluid to slightly thick, pours easily.
• Colour : white, homogeneous.
• Storage : Keep refrigerated, like fresh dairy products; once opened, consume quickly (follow the label).

What this changes: it is easy to drink, but above all it is very practical for “soft” cooking.

Possible benefits (without excessive promises)

Buttermilk is not a "cure," but it can be beneficial as part of a balanced diet, particularly because it is a fermented food. Research on fermented foods suggests possible links to the gut microbiota and digestive health, but the effects depend on the specific products, strains, and quantities consumed.

• Digestive tolerance : fermentation can reduce some of the lactose, which helps some sensitive people (but is not suitable for everyone).
• Microbiota : Fermented foods are being studied for their potential impact on microbial diversity and certain inflammatory markers; a general public benchmark is presented by Harvard Health (scientific source).
• Protein and calcium content : according to the brand, it remains close to that of a classic fermented milk.
• Culinary alternative : replaces cream/yogurt in some recipes, with less fat.

Note: If you're looking for a "probiotic" effect, the product must contain a sufficient quantity of live cultures, which varies. Information on probiotics and their limitations is summarized by the NCCIH (scientific source).

Table: Buttermilk vs. yogurt vs. kefir vs. milk (useful differences)

How to use buttermilk (drinking + cooking)

1) As a drink

• Natural, fresh, by the glass.
• With a pinch of cinnamon or vanilla (if you like).

In practice: start with a small portion if you are not used to fermented milks.

2) In “soft” cuisine

• Pancakes / waffles : the acidity reacts with the bicarbonate → lighter texture.
• Cakes : replaces some of the milk/yogurt for a more moist texture.
• Crepes : a softer version, slightly tangy taste.

In practical terms: if a recipe calls for 250 ml of milk, you can often try 250 ml of buttermilk, then adjust the sugar/salt to taste.

3) Sauces and seasonings

• Cold “yogurt” type sauce (herbs, garlic, lemon) but more fluid.
• Light creamy vinaigrette base.

4) Marinades

The acidity and enzymes can slightly tenderize certain meats/poultry. Use it like buttermilk: spices + herbs + salt, then chill.

What can be used as a substitute for buttermilk (and how can it be made quickly)?

If you can't find any:

• Option 1 (simple) : plain yogurt + a little water to achieve a fluid texture.
• Option 2 (homemade buttermilk type) : milk + lemon juice (or vinegar) and let it rest for 5–10 minutes. This isn't true fermentation, but it replicates the acidity useful in baking.
• Option 3 : milk kefir (stronger taste, sometimes more fermented).

What this changes: in pastry making, the important thing is often acidity + texture; for the “fermented” interest, a real fermented product (buttermilk/kefir/yogurt) is better.

Common mistakes (and how to avoid them)

• Confusing buttermilk with expired milk : buttermilk is tangy but should remain pleasant, without an abnormal strong odor.
• Boiling it : at high heat, it can "split." It's best used cold or heated gently.
• Believing it to be lactose-free : it may contain less, but not necessarily zero.
• Overconsumption at once : if you are sensitive, increase gradually.
• Forget about overall balance : it's not a miracle product; it fits into a varied diet.

For whom is it useful (and for whom is it less suitable)

• Useful if : you are looking for an alternative to milk in baking, you like slightly tangy tastes, you want to vary fermented foods, you digest fermented milks better than milk.
• Avoid or adapt if : allergy to milk proteins (PLV), dairy-free diet, severe lactose intolerance (test carefully), digestive disorders sensitive to fermented products (on a case-by-case basis).

If you have a significant digestive condition, consult a healthcare professional. For an overview of nutrition and health, the WHO offers helpful general guidelines (scientific source).

How many to take and how often?

There is no universal “official dose”. A simple guideline:

• as a drink: 100–200 ml, 3–5 times per week depending on tolerance,
• In cooking: replaces milk/yogurt in a recipe, without trying to “force” it.

In practice: your digestion is the best indicator (bloating, discomfort, etc.).

FAQ What is buttermilk?

Is buttermilk the same as regular buttermilk?

Often very similar in usage. But “buttermilk” can also refer to the liquid from traditional churning. In stores, “buttermilk” is frequently a fermented milk such as buttermilk.

Does buttermilk contain probiotics?

It contains lactic acid bacteria; the "probiotic" effect depends on the strains and quantities. Check the label (live cultures, etc.). Reference: scientific source.

Is buttermilk good for digestion?

For some people, yes, because it is fermented and may be better tolerated than milk. But this is not always the case.

Can it be heated?

Yes, but gently. At high heat, it can coagulate. Best used in cold sauces, marinades, and pastries.

Can buttermilk be replaced with milk + lemon?

Yes for baking (acidity + reaction with bicarbonate). No for the "fermented" benefit, because it's not true fermentation.

Is buttermilk lower in calories?

It depends on the brand and the fat content. Compare the label to the milk/yogurt you use.

Is it suitable for children ?

In general, like a classic fermented dairy product, but adapt to habits, age and any allergies/intolerances (seek professional advice if in doubt).

What is the difference with milk kefir?

Kefir often involves yeasts and bacteria, can be more fermented, and is sometimes fizzy. Buttermilk is generally milder and simpler in flavor.

Key points to remember 

• Buttermilk is a fermented milk from Brittany, sweet and tangy.
• Great for pancakes/crepes/cakes and cold sauces.
• It may be better tolerated than milk by some, but not by everyone.
• If you don't have any: diluted yogurt or milk + lemon for baking.

If your goal is to improve your digestive comfort, you can also consult our page dedicated to digestion. For a holistic approach to well-being, see well-being. If you are experiencing associated fatigue, explore fatigue and energy.

Sources

• NCCIH — Probiotics: What You Need To Know
• Harvard Health — Fermented foods can add depth to your diet
• WHO — Healthy diet (fact sheet)
• PubMed — database of studies (search: fermented dairy, buttermilk, lactic acid bacteria)