Why Do Sugar Substitutes Leave an Aftertaste? (Explained)

To maintain our health and fitness levels, more and more of us decide to eliminate sugar from our diet. Sweet flavors can be achieved using several natural and artificial sweeteners instead of sugar.

Sugar substitutes are low in calories and have a low glycemic index. However, many people complain that some sweeteners cause an unpleasant taste in addition to sweetness. The purpose of my article is to explain why some sugar substitutes cause an unpleasant aftertaste.

The aftertaste of sweeteners is most often described as bitter or metallic. According to several studies, sugar substitutes cause an aftertaste because they activate not only the sweet taste receptor on our tongue, but also the bitter taste receptors.

We only have one sweet taste receptor, compared to 25 bitter taste receptors. Some people have more sensitive receptors for bitter tastes. They therefore have a more pronounced and stronger perception of the unpleasant aftertaste. The reason people perceive flavors differently is due to genetic differences.

Sweeteners that cause a bitter or metallic taste include Stevia, aspartame, saccharin, cyclamate, and acesulfame-K.

Sugar substitutes are regularly added to low-calorie and diabetic products. Confectionery and beverage companies use several sweeteners in combination to complement each other and offer the best possible taste.

However, many people still don’t like drinks made with different sugar substitutes because of their pronounced aftertaste.

Natural sweeteners

Natural sweeteners are sweet-tasting compounds produced from plants.

Adding sweetener to the cup


Sugars are considered natural sweeteners. These include beet sugar and cane sugar (sucrose), fruit sugar (fructose), malt sugar (maltose), milk sugar (lactose), and dextrose.


Sugar alcohols

The group of natural sweeteners also includes sugar alcohols, which occur in nature but can also be produced artificially. Their calorie content and glycemic index are lower than those of sugar. Sugar alcohols include xylitol, erythritol, isomalt, sorbitol, and mannitol.


Stevia is also a natural sweetener produced from the leaves of the Stevia rebaudiana plant. It is native to Paraguay and Bolivia but can be grown in many parts of the world.

 Steviol glycoside is a sweet powder-like substance extracted from Stevia. It contains zero calories and does not affect blood sugar levels. The disadvantage of stevia is that it causes a bitter taste.

Stevia plant
Stevia plant

Does stevia leave a bitter aftertaste?

Due to the natural chemical composition of stevia, it activates two bitter taste receptors in our mouth and thus causes a bitter taste.

Stevia contains zero calories and is not harmful to our teeth. It also does not raise blood sugar levels. Due to its content of steviol glycosides, stevia is approximately 300 times sweeter than sugar. However, many people are reluctant to consume it, as it leaves an unpleasant aftertaste when used in large quantities.

Experiments are underway with the selective cultivation and processing of the stevia plant, with the aim of increasing the sweet-tasting substances.


Monk fruit

Monk fruit sweetener is made from the luohan guo fruit native to China and is calorie-free. It has a distinctive taste different from sugar and causes a slight aftertaste.

Artificial sweeteners

Artificial sweeteners have a strong sweetening effect, but their caloric value is very low and they do not affect blood sugar levels. These include aspartame, acesulfame, neohesperidin, cyclamate, and saccharin. Artificial sweeteners tend to have a strong aftertaste.

Combined use of cyclamate and saccharin

Sugar substitutes have been on the market for a long time, and manufacturers are constantly working on combinations that can eliminate the aftertaste.

It has been known for decades that the combination of cyclamate and saccharin can neutralize the bitter aftertaste. However, they didn’t know much about the reason for this until the 2000s, when scientists discovered some bitter taste receptors.

Both cyclamate and saccharin actually block the bitter receptors activated by the other. Cyclamate is not approved for use in the USA due to its potential adverse effects. In the European Union, Canada, and many other countries, however, it has been classified as safe in the recommended amount.

What sweetener tastes most like sugar?

The sweetener with the most similar taste and texture to sugar is xylitol, also known as birch sugar. It is very easy to use as a sugar substitute, as it has the same sweetening power as plain sugar and does not leave an aftertaste.


Despite its name, birch sugar is not made from birch, but mostly from corn. It belongs to the group of sugar alcohols, which are natural components of some plants, including birch and some grains.

One of the beneficial properties of xylitol is its low glycemic index, which allows it to be consumed by diabetics in moderate amounts. In the preparation of cakes, creams, and cookies, xylitol is a good substitute for sugar, as it not only gives a sweet taste but also adds bulk.

With its antibacterial effect, birch sugar contributes to the health of our teeth, unlike simple sugar. It also contains fewer calories than sugar.

Among the disadvantages of xylitol, it should be mentioned that it can cause diarrhea when consumed in large quantities.

Xylitol, on the other hand, is very dangerous for dogs, even in small amounts it is deadly for them. Dog owners are therefore advised to ensure that their pets do not have access to it under any circumstances.

Final thoughts

Sugar substitutes are common both in-home use and in the industrial production of confectionery and soft drinks.


One of their good features is that they contain significantly fewer calories than plain sugar. Since they raise blood sugar levels only slightly or not at all, they can also be consumed by diabetics.

The disadvantages of sweeteners include the unpleasant aftertaste they cause, often described as bitter or metallic. This aftertaste is caused by the fact that sugar substitutes activate the bitter receptors in our mouth together with the sweet receptors.

Depending on the person, there are those who are less sensitive to this aftertaste, but for others, it causes an unpleasant experience. As mentioned above, xylitol is the most similar to sugar in taste and texture and does not cause an unpleasant aftertaste.



My name is Debora, the founder of My Delicious Sweets, and a qualified confectioner with broad experience in the confectionery industry. On my blog, I will share important, interesting, and fun facts about food, along with some of my favorite recipes.

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