Skip to content
logo The DIY portal for home and garden
Visible after the harvest

Why do some apples turn glassy?

Why do apples turn glassy?
Why do apples turn glassy? Photo: Franka Kruse-Gering/myHOMEBOOK

October 10, 2024, 10:54 am | Read time: 3 minutes

“So that you can still bite down hard tomorrow” was once the slogan of a toothpaste commercial. But if you suddenly discover glassy spots after taking a big bite of an apple, the bite will probably get stuck in your throat. myHOMEBOOK editor Franka Kruse-Gering explains what the so-called “glassiness” of apples is all about.

Share article

Glassy areas are particularly noticeable on freshly harvested apples. The transparent areas usually appear around the core and, as the name suggests, are reminiscent of glass. Who or what is to blame for these transparent areas in the apple?

Why does an apple turn glassy?

Glassiness in apples is not caused by pests or a disease, but by metabolic problems, writes the Bamberg District Association for Horticulture and Landscape Conservation. Too much sun and too high temperatures in the summer months can cause apples to produce too much starch or sugar. As a result, the apple stores too much water in certain areas, and these areas then appear glassy or watery.

However, another reason apples become glassy is an imbalance of leaves and apples. Glassiness can occur if an apple tree has too much foliage and too few apples in proportion. According to the Plant Protection Service of the Giessen Regional Council, however, it is not yet clear why exactly these metabolic problems occur.

Can glassy apples still be eaten?

The harvest is by no means lost if glassiness occurs. The apples taste as good as ever. The only drawback is the way they look when you cut them open. However, the glassiness is only clearly visible on freshly harvested apples. The longer the apples lie, the more the accumulated water spreads throughout the fruit.

How can you prevent glassy apples?

Glassy apples can affect anyone who has an apple tree in their garden. However, prevention is possible. Care should be taken to prune the tree regularly and professionally and to keep an eye on fertilization so that leaves and fruit can develop evenly.

In addition, some varieties tend to develop glassy spots. According to the Bamberg District Association for Horticulture and Landscape Conservation, this mainly affects trees that tend to produce sweet apples. Examples include “Alkmene”, “Goldparmäne”, “Gloster” and “Cox Orange.”

More on the topic

Turning glassy apples into apple sauce

Applesauce is not only quick to make but also healthy and sugar-free. This makes it ideal for children, too. Another advantage is that the glassy spots are no longer visible.

What you need:

  • You need about three kilos of glassy apples for this recipe.
  • You should already have 300 milliliters of water. Depending on how juicy the apples are, you may need a little more or less.
  • Preserving jars or old jam jars.

How to make apple sauce

  • Peel and core the apples.
  • The next step is to put the apples in a pan with the water and simmer for around 25 minutes.
  • Depending on the consistency you want, you can mash the overcooked apples a little or chop them up with a hand blender.
  • Finally, pour the hot apple sauce into the jars and leave to cool upside down.

This article is a machine translation of the original German version of MYHOMEBOOK and has been reviewed for accuracy and quality by a native speaker. For feedback, please contact us at info@petbook.de.

Topics #amazon Garden plants
Your data privacy when using the share function
To share this article or other content via social networks, we need your consent for this .
You have successfully withdrawn your consent to the processing of personal data through tracking and advertising when using this website. You can now consent to data processing again or object to legitimate interests.