September 23, 2026, 1:07 pm | Read time: 3 minutes
As soon as the windows are cleaned, the first streaks, dust deposits, or rain marks often reappear. A new household tip is supposed to help: a dash of glycerin in the cleaning water. myHOMEBOOK asked an expert if this trick really works.
Elke Messerschmidt from the Competence Center for Home Economics explains why glycerin actually has special properties and why some professionals recommend it for window cleaning.
What is Glycerin Anyway?
Glycerin is a colorless, odorless, and slightly syrupy liquid used in cosmetics, pharmaceuticals, and various household products. Chemically, it is a form of alcohol.
According to Messerschmidt, glycerin has good dirt-dissolving properties. Therefore, it is occasionally recommended as an additive for window cleaning. Although the expert has not used the product herself, she is familiar with the recommendations from professional practice.
Why Glycerin Could Keep Windows Clean Longer
The actual effect of glycerin is not in the cleaning itself but in the film that remains on the glass pane after cleaning.
“When you clean windows with glycerin, this layer binds the humidity. This means a thin, even, and transparent water film forms, acting like a protective layer over the glass pane,” the expert explains. This film remains relatively long. The reason: Glycerin is significantly more viscous than water and evaporates very slowly. “Since glycerin has a relatively high viscosity and, unlike water or ethanol, hardly evaporates, this film remains stable for a long time,” Messerschmidt adds.
This may prevent new dirt from settling on the glass surface as quickly. At least, the re-soiling of the windows is slowed down.
Related: When You Should Never Clean Windows
How to Use Glycerin
If you want to use glycerin for window cleaning, you should not apply it undiluted to the pane but mix it with the cleaning water. The recommended amount depends on the specific product, the expert explains. Consumers should always follow the manufacturer’s dosage instructions.
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Where to Buy Glycerin
If you want to try the household trick, you don’t have to search long. Glycerin is widely available, such as:
- in pharmacies
- in some drugstores
- online
The expert recommends paying attention to the specific product description and following the manufacturer’s application instructions.
How to Store Glycerin Properly
To ensure the product retains its properties as long as possible, it should always be tightly sealed after opening. Additionally, it is advisable to store it in a cool and dry place. Direct sunlight and significant temperature fluctuations should be avoided as much as possible.