Why is there oil in my almond milk? A guide to natural separation and stabilizers

January 5, 2026 •

4 min read

According to a 2021 report, non-dairy milk now accounts for 10% of the total milk market in the US, so many consumers are familiar with seeing their almond milk separate. This oily or separated layer is often just a natural outcome of fats and water dividing, or it can be a sign of the oils and stabilizers added to commercial products.

Quick Summary

The appearance of oil or separated layers in almond milk is a normal phenomenon caused by the natural emulsion of fat and water. This effect is common in homemade versions and can also occur in store-bought products due to temperature changes or additives.

Key Points

Natural Emulsion: Almond milk is an emulsion of fats and water, which naturally separates over time, especially in homemade versions.
Commercial Additives: Store-bought varieties often contain added oils (sunflower, canola) and emulsifiers (lecithin, gums) to create a more stable, uniform texture.
Curdling in Hot Drinks: The most common reason for curdling is the interaction of cold almond milk with hot, acidic liquids like coffee.
Simple Re-Emulsification: For natural separation, a vigorous shake of the carton or jar will re-suspend the fats and solids.
Preventing Coffee Curdle: To avoid curdling in hot beverages, gently warm the almond milk first or add the hot liquid slowly to the milk.
Check for Spoilage: If the separation includes foul smells, persistent thick clumps, or a sour taste, the milk is likely spoiled and should be discarded.
Health Consideration: While some are concerned about added oils or additives, the quantity in commercial almond milk is often minimal. For a cleaner product, opt for brands with fewer ingredients.

The Science of Separation: Why Almond Milk is a Natural Emulsion

At its core, almond milk is an emulsion, which is a mixture of two or more liquids that are normally immiscible, like oil and water. In this case, it's the natural fats and proteins from almonds suspended in water. Emulsions are inherently unstable and, over time, gravity causes the denser particles to settle to the bottom and the lighter oils to rise to the surface. This is why a homemade almond milk, made only with almonds and water, will almost certainly show a distinct oily layer and sediment after sitting in the refrigerator. This is a completely normal process and does not mean the milk has gone bad. A simple shake of the carton or jar is all it takes to re-emulsify the mixture and restore its creamy consistency.

Store-Bought Almond Milk vs. Homemade: The Role of Additives

If you're accustomed to store-bought almond milk that seems to never separate, the reason lies in the additives used by manufacturers. Unlike pure homemade versions, commercial products contain ingredients designed to create and maintain a uniform texture and longer shelf life.

The Purpose of Added Oils and Stabilizers

Commercial almond milk frequently includes added oils, such as sunflower or canola oil, to boost its fat content and enhance the mouthfeel. These oils, along with stabilizers and emulsifiers, help to prevent the natural separation that would otherwise occur. Some common additives you might find on an ingredient list include:

Lecithin: Often derived from sunflower or soy, lecithin acts as an emulsifier to keep the fats and water mixed together.
Gellan Gum: This plant-based gelling agent is used to thicken the liquid and prevent ingredients from separating.
Carrageenan: Extracted from seaweed, carrageenan functions as a thickener and emulsifier. However, it has been linked to gastrointestinal issues in some studies.

For consumers seeking to avoid these additives, reading the ingredients label is crucial. Many clean-label brands now produce almond milk with just almonds, water, and salt. A quick shake is the only requirement before use for these additive-free products.

Comparing Store-Bought and Homemade Almond Milk


Feature	Store-Bought Almond Milk	Homemade Almond Milk
Ingredient List	Can contain added oils, emulsifiers, and flavors.	Typically includes only almonds, water, and optional salt/sweeteners.
Stability	Highly stable and uniform in texture due to additives.	Naturally separates into layers of oil and solids.
Shelf Life	Lasts weeks or months unopened.	Stays fresh for only 4-5 days in the refrigerator.
Oil Layer	Less likely to form a visible oil layer if additives are effective.	A visible oil layer is a natural, guaranteed outcome.
Flavor Control	Flavor is consistent across batches but can be masked by additives.	Flavor can vary slightly depending on the almonds used but is purer.

The Curdling Conundrum: Heat and Acidity in Your Coffee

Beyond simple settling, almond milk can appear to have an oily or curdled texture when added to hot beverages like coffee or tea. This is a different reaction caused by two primary factors:

Temperature Shock: Pouring cold almond milk directly into a hot liquid can cause the proteins to rapidly denature and coagulate, leading to a curdled appearance.
Acidity: Coffee is naturally acidic, and this acidity can cause the proteins in almond milk to clump together. This is why almond milk is more likely to curdle in a strong, acidic black coffee than in a milder, less acidic tea.

To prevent this, you can gently warm the almond milk beforehand or slowly add the hot coffee to the milk rather than the other way around. Using a barista-blend almond milk, which contains added stabilizers for this exact purpose, can also help.

How to Assess Your Almond Milk: Separation vs. Spoilage

While separation is normal, it's important to distinguish it from true spoilage. A separated but otherwise good almond milk will remix smoothly with a shake and have a normal, nutty scent. Spoiled almond milk, on the other hand, will exhibit distinct signs that go beyond simple separation. These include:

Foul Odor: A rancid, sour, or 'cardboard' smell is a strong indicator of spoilage.
Thick Chunks: Instead of a simple layer, you'll see persistent, chunky curds that don't reintegrate with shaking.
Off Taste: The taste will be sour and unpleasant.
Mold: Black mold forming on the surface is a clear sign to discard the product immediately.

Conclusion: Decoding the Oil in Your Almond Milk

The presence of an oily layer or visible separation in your almond milk is almost always a normal and natural result of its core composition as an emulsion of water and almond fats. For homemade versions, this is an expected outcome due to the lack of stabilizing additives. In store-bought brands, separation can still occur despite added ingredients, especially when exposed to heat and acidity. By understanding the natural science of these emulsions, you can quickly differentiate between harmless settling and true spoilage. The solution is often as simple as a brisk shake, allowing you to enjoy your beverage without worry.

For a deeper dive into how food additives are used in the industry, you can refer to authoritative resources like the National Institutes of Health(https://pmc.ncbi.nlm.nih.gov/articles/PMC4808858/).

Summary of Causes for Almond Milk Separation

Natural Settling: The normal separation of fats and water in an emulsion, common in homemade almond milk.
Added Oils: Manufacturers sometimes add oils like sunflower or canola to enhance texture and mouthfeel.
Emulsifiers Failure: The stabilizers added to commercial brands can become less effective over time or under certain conditions.
Heat Shock: Adding cold almond milk to hot liquids like coffee causes the proteins to curdle.
Acidity Reaction: The acidic nature of coffee and other liquids causes proteins in the milk to coagulate.
Spoilage: True spoilage is indicated by a foul odor, chunky consistency, and bad taste, not just a simple separation.

Frequently Asked Questions

Yes, separation is completely normal for almond milk, especially homemade versions. It is an emulsion of water and almond fats, and over time, the fats and solids will naturally settle to different layers. A quick shake will fix it.

Not necessarily. Natural separation is not a sign of spoilage. However, if the separation is accompanied by a foul or sour smell, a chunky texture, or a bad taste, it has likely gone bad and should be discarded.

Commercial almond milk can contain added oils like sunflower or canola, along with stabilizers, to maintain consistency. If the stabilizers become less effective over time or are absent, an oily layer can form. It can also be natural separation if the product has a minimal ingredient list.

Curdling in hot drinks is caused by temperature shock and acidity. Adding cold almond milk to hot, acidic coffee can cause the almond proteins to rapidly coagulate and clump together.

You can prevent curdling by gently warming the almond milk before adding it, or by pouring the hot coffee slowly into the milk. Using a barista-style blend of almond milk, which has extra stabilizers, also helps.

Many commercial almond milks contain additives like gums, lecithin, and carrageenan to prevent separation. While generally considered safe by regulators, some studies and reports have raised concerns about potential gut issues, particularly with carrageenan.

Yes. Separation is a normal, harmless process where the components of the emulsion settle over time and can be mixed back together by shaking. Curdling is an irreversible reaction, often triggered by heat or acid, that causes proteins to clump permanently.