Why Don’t Vinegar and Oil Mix?

Before getting in the details of why vinegar and oil do not mix, you first need to know a little bit about both of them.


Fermentation is the process of obtaining vinegar by turning sugars into acetic acid. You can also prepare vinegar from any other fruit or material that contains sugar. The most well-known vinegar include balsamic, apple cider, white, distilled, fruit, white or red wine, and rice vinegar.

Balsamic vinegar is made from grapes, and it has a syrupy texture and sweet flavor. The Reggio Emilia and Modena provinces of Italy are the traditional producers of Balsamic vinegar. The top of the range vinegar is market with DOC sign and aged for 12 to 25 years. Acetobalsamico, made of strong vinegar, concentrated grape juice, coloring, and sweeteners, is the less pricey version.


You can use Balsamic vinegar for sauces, salads, or dipping. Moreover, fruit vinegar is a product of fruit juice fermentation, which is without any additional flavoring. You can find cranberry, strawberry, gif, raspberry, or even date vinegar in the markets. The varieties of vinegar, in combination with oil, are ideal for salad dressing or dipping bread.

White or red wines are used to prepare wine vinegar and may vary in quality like all the other wines. Wine vinegar is suitable for marinades or dressing.


Edible oil

Edible oils are extracted from seeds, fruits, or nuts using mechanical pressure machines. You can also extract some oils by applying heat for better extraction. However, cold-pressed oil is of superior quality because this process preserves all the valuable properties and is suitable for salads and dipping.

When it comes to dipping and salad, olive oil is one of the most well-liked oils. But have you tried some nut oils like walnut, pistachio, hazelnut, or seed oils, such as pumpkin or sesame? If not, then buying one of them would widen up the field of your kitchen experiments.

What Happens When You Mix Vinegar And Oil?


When you mix oil and vinegar, it forms a temporary mixture that eventually gets separated into two layers after a few seconds. The reason why this happens is that both the liquids are immiscible. It means that these two substances cannot get mixed and form a permanent emulsion.

An emulsion is a suspension of any two liquids that do not stay mixed and do not form a permanent mixture, like vinegar and oil. Usually, when you pour oil into vinegar, the oil does not mix and float on the top of the vinegar. Vinegar is denser than the oil, but the prime reason why this occurs is that the vinegar is a polar substance, and the oil is a non-polar one.

The substances having dissimilar molecular structures hardly interact.  It is essential to whisk the vinegar and oil together to keep the separation of the liquids from occurring and result in the formation of a temporary emulsion. Still, after a short period, this emulsion will separate into two layers of the original liquids, one floating on the top of the other.

An emulsifying agent molecularly holds these two liquids together and forms a permanent emulsion. Although the combination of vinegar and oil and water and oil are the two classic examples of immiscible substances, there are several others as well, including chloroform and water and hexane and water. Alternatively, a few examples of miscible substances can be either grain alcohol and water or water and acetic acid.

So, Why Vinegar and Oil Do Not Mix?

Vinegar and oil do not mix because lipids are not soluble in water. Vinegar does not form a solution with vegetable oil since it is mostly water. The primary reason water and oils do not mix is that their molecules are attracted to others of their kind; both exclude each other. It means that water molecules attract other water molecules, and similarly, oil molecules attract other oil ones.

The reasons that molecules form bonds with some molecules and repel others relate to their molecular polarity. Some molecules have negative charges, some have positive, and some have both. So, the molecules with the same charge repel each other. Whereas the oppositely charged molecules attract each other and form bonds.

While water and oils do not mix to make a solution, some of their molecules can form solutions with both types of molecules; soap is an excellent example of a substance that bonds with both lipids and water. When you add soap in a container that contains both water and oil, the soap will form a bond with both the substances, making a homogeneous mixture.

However, the new mixture is called an emulsion, and it is not a solution; it represents a different kind of chemical combination. And this is the reason why soaps work so well in cleaning greasy dishes.

How to Mix Oil and Vinegar?

Using a lot of force is the only secret to mixing vinegar and oil. Because of the molecular structure, the molecules of oil and vinegar repel each other and are hard to mix. Fat molecules in the oil are hydrophobic, which means they are not attracted to water. On the other hand, the water molecules in the vinegar are hydrophilic, which means they are only attracted to water.

Once you successfully break the molecules apart using lots of force, the tiny droplets combine. A natural emulsifier, known as lecithin, keeps the liquid combined. Commercial producers use substances that have the same effect as lecithin, such as xanthan gum.

Mixing Technique

When it comes to preparing a classic vinaigrette, you have several options to choose from. It is typically made with 1 part vinegar and 3-parts oil. The following three methods combine the liquids for only a few minutes, and then they get separated again.

  • Whisk both the liquids in a bowl or container using a wire whisk.
  • Place the vinegar and oil in a jar with a tight-fitting lid and then shake it vigorously for about thirty seconds.
  • Blend the vinegar and oil using a food processor or countertop blender or an immersion.

Bottom Line

Both vinegar and oil are immiscible liquids, which means they do not get mixed. Their molecular charge and structure make them form bonds with a similar kind of substances. However, using an emulsifier agent or a lot of force, you can combine the two, but it is a very burdensome and effort-taking process.