Is Vinegar Flammable? Can It Catch Fire?

Vinegar is a standard ingredient in most homes. Whether it is kept in the kitchen cupboard or the cleaning cupboard, we manage to find plenty of jobs for this useful liquid, and have done so for many thousands of years.

These days there are many different varieties of vinegar available, some with distinctive flavorings, colorings and uses, however, the most distinctive quality of all types of vinegar is surely the smell.

Vinegar has a potent and sharply acidic smell, and it has led many people to wonder whether it is in fact a flammable substance?

After all, vinegar is made from alcohol, which can be highly flammable. Luckily, you have not been dousing your dinner in flame fuel all these years, as vinegar is not a flammable substance and it will not catch fire.

Read on to find out how it is made, why it is not flammable, and how the many different varieties of vinegar compare.

Will Vinegar Catch Fire? Is It Flammable?

What Is Vinegar Made Of?

Vinegar is a mixture of acetic (ethanoic) acid and water. It will sometimes contain small amounts of other flavorings and colorings in the form of phenolic acids, aldehydes and flavonoids depending on what type of vinegar it is.

Acetic acid is a highly flammable substance, so it is understandable why people would suspect vinegar to be the same.

However, vinegar is not flammable because it has a very low percentage of acetic acid compared to a high percentage of water. Water does not catch on fire, it actually extinguishes flames, meaning it is definitely not flammable.

Most cooking vinegar contains 5-8% acetic acid  and 92-95% water. As you can see, the balance is strongly swayed towards the non-flammable ingredient, which is why vinegar is perfectly safe to use near heat and flames. 

Can Vinegar Catch On Fire?

Normal household vinegar will not catch on fire, and nor will other specialist vinegars designed for cleaning or culinary purposes. This is because the flammable component in vinegar is so diluted by the water content that it loses its flammable properties. 

Acetic acid is the main active ingredient in vinegar that gives it that fermented flavor we all know and love.

Acetic acid makes up between 5% and 8% of vinegar, and is a highly flammable substance, with a flashpoint of 104 degrees Fahrenheit. This means, when it is heated to 104 degrees Fahrenheit it will catch on fire… but only in its pure form. 

Because vinegar is made of 92-95% water, the acetic acid is diluted and the substance is not flammable.

Of course, if you were to heat vinegar to an exact temperature, so that the water content evaporated and all that was left was acetic acid, then technically you could cause it to catch flame.

However, this would be very difficult to achieve, as the temperature would have to be highly controlled to ensure that the acetic acid didn’t vaporize with the water.

In essence, you would have to be a talented scientist and create a super controlled environment in order to make vinegar catch on fire.

Is It Dangerous To Boil Vinegar?

Although vinegar will not catch on fire, it still isn’t a great idea to boil it, and we can’t really think of a reason why you would want to. Vinegar fumes can be harsh on the nose and eyes, and there are not any notable benefits to boiling a pan of vinegar in your kitchen.

You will only waste a handy ingredient and make your house smell funny. Although it is not dangerous to boil vinegar, it is not beneficial either and you should only do so if you are in a well ventilated kitchen or area.

If that hasn’t convinced you, you might be interested to know that vinegar is corrosive when it is boiled. This is because the PH of vinegar is affected by heat, so the acetic acid element of the liquid will cause pans to rust and corrode.

Unless you choose to use a glass container (which is not affected by the increased acidity of vinegar) then you could end up ruining some perfectly decent pots and pans by boiling vinegar in them.

Whatever happens, never boil vinegar over a coal fire because the carbon monoxide created by the heated coals can be dangerous and highly toxic to humans.

Are Vinegar Fumes Good For You?

Some websites and articles online claim that vinegar fumes help to disinfect your house, however this is an internet myth and has no scientific basis whatsoever.

Even though vinegar is sometimes used to clean surfaces and lift bacteria, vinegar fumes are not strong enough to disinfect your home, and will only make your walls and furniture smell bad.

They will not help to erase flu or other viruses from the air or from the surfaces in your home. There may be great health benefits to drinking apple cider vinegar in warm water (more on that later), but there are no known health benefits to vinegar fumes.

Are Vinegar Fumes Bad For You?


On the whole, vinegar fumes are safe to inhale in small amounts, however you should not inhale them over a prolonged period of time or in large amounts.

Put simply, it is perfectly safe to inhale vinegar fumes during everyday use in the kitchen and around the house. This is because the fumes are not strong, neither are they highly concentrated or toxic. 

If you were to be exposed to highly concentrated vinegar fumes over a long period of time you could be negatively affected however. This would only ever be in very extreme situations where the vinegar fumes in the air deprived you of the oxygen your body needs.

For example, if you worked in a vinegar plant all day every day, then you would need to wear the appropriate protective masks and goggles, but these would no doubt be provided by your employers.

Is Cleaning Vinegar Flammable?

Vinegar that is marketed as ‘cleaning vinegar’ or ‘household vinegar’ is actually very similar to cooking vinegar, otherwise known as ‘spirit vinegar’ or ‘white vinegar’. The only difference is that household vinegar is slightly more acidic than cooking vinegar.

It has about 6% acetic acid compared to 5% in kitchen vinegar. This is so that it can lift bacteria and marks off glass and stainless steel surfaces effectively. In Great Britain, newspaper is used to rub vinegar onto surfaces to achieve a crystal clear finish. 

Despite the slightly higher acid content, household vinegar is still far too weak to be flammable and is perfectly safe to have around the house.

Is Cider Vinegar Flammable?

Apple Cider Vinegar is famous for its health benefits, especially when it is unpasteurized and still contains ‘the mother’ (a form of healthy bacteria). When a teaspoon is mixed with warm water and drunk daily, it has been said to improve digestive and general health.

However, apple cider vinegar is chemically very similar to all other vinegars, and only gets its flavor from the apples that are fermented to create alcohol, which then goes through a second fermentation to create acetic acid.

The proportion of acid to water remains incredibly low (only 4-5%) and therefore apple cider vinegar is not flammable.

How Is Vinegar Made?

Traditionally, vinegar was made by letting alcohol (usually beer or wine) ferment for a very long time until it became acetic acid.

When this acid was mixed with water and other flavoring it created vinegar which could be used in sauces, as a condiment, and also as a preservative when pickling food. 

This process of natural fermentation can take months (and even a year) to complete. These days, vinegars made this way are highly expensive.

Cheap vinegar (or spirit vinegar) is made through a much speedier fermentation process that was developed in the 20th century and cuts the fermentation time down to 1-2 days!

Source materials for vinegar are varied, but are usually fruits, grains, alcoholic beverages, or sugar.

When Was Vinegar Invented?

The first records of vinegar date back to the Babylonian period, around 3000 BC! That is over 5000 years ago! There are also records of the ancient Egyptians using vinegar to preserve foods, and the ancient Romans were well known to use it in their culinary repertoire.

So, as you can see, this distinctive ingredient has been around for many, many centuries and it is used all around the world by all different cultures and culinary traditions. It is well established as a safe and useful substance. 

The word ‘vinegar’ actually first entered the English language from the old French word Vyn Egre. This translates as ‘Sour Wine’, which seems fitting for something that has such a distinctive sour taste.

In Conclusion

Vinegar is a wonderful ingredient to have in your home. It helps to keep surfaces clean and shiny, and it is great for making vinaigrettes, dressings, sauces and condiments.

Although it does contain acetic acid which is a flammable substance, the acid content is so low in vinegar that it is not flammable and is perfectly safe to keep at home and use near heat and flames.

However, you should always be safety aware and extra careful whenever you are cooking or working near fire.