Foods that Cause Natural Stone Etching

If you have already installed natural stone worktops or you are planning on installing stone surfaces, it’s important to know how to care for these surfaces. Just as you need to know how to clean your worktops, you also need to keep in mind that there are a few substances that are particularly harmful in terms of etching.

The pH factor

When you work with different ingredients in your kitchen, you might not be aware of the fact that different foods have different pH levels. The lower the pH, the more acidic the substance. 7 is considered to be neutral on the pH scale but this also does not mean that alkaline substances cannot cause harm too. Of all the foods out there, alcohol (like wine), fruit juice, tomatoes, vinegar and pasta sauce have a pH level of between 2 and 3. If you find this surprising, here are the pH levels of some foods that you commonly use in your kitchen:

  • Wheat flour: 5.5 – 6.5  
  • Butter: 6.1 – 6.4  
  • Peas: 5.8 – 6.4  
  • Pumpkin: 4.9 – 5.5  
  • Sweet potatoes: 5.3 – 5.6  
  • Sugar: 5 – 6  
  • Molasses: 5 – 5.5  
  • Honey: 3.9


Since there is no way of avoiding the use of these or similar ingredients in your kitchen, it’s important to remember that prevention is the best approach. Always use chopping boards and coasters. Clean up spills thoroughly as soon as they happen to prevent the acidic properties from causing etching. Seal the stone surface regularly for added protection.

Of course, etching may still occur no matter how careful you are. In this case, it’s good to note that your stone worktops are not totally ruined. There are ways of repairing etch damage. The type of repairs needed will depend on how bad the etching is. If the surface is rough to the touch, it means that the etching has penetrated the stone and, in this case, you should have your worktops professionally restored.