It can be quite jarring to wash a fresh bowl of grapes only to have them smell like a swimming pool. While your first instinct might be to blame a heavy bleach wash at the grocery store, the reality is usually a bit more "scientific."
Here are the three primary reasons why grapes can smell like chlorine:
1. Sulphur Dioxide Treatments
This is the most common culprit. To prevent mold, decay, and "nesting" (where one bad grape ruins the whole bunch), producers treat table grapes with Sulphur Dioxide during storage and transport.
The Reaction: While Sulphur Dioxide isn't chlorine, it has a sharp, pungent, and chemical-like odour that many people’s brains categorize as "chlorine-like" or "bleach-like."
The Solution: A thorough soak in cold water with a tablespoon of baking soda usually neutralizes this residue.
2. Natural Compounds (Methyl Anthranilate)
Certain varieties of grapes, particularly Concord or "slip-skin" grapes, contain a natural ester called Methyl Anthranilate.
This compound provides the classic "grape" flavor used in sodas and candies.
However, in high concentrations or when the grape is slightly overripe, this chemical aroma can take on a sharp, medicinal, or cleaning-fluid scent that mimics chlorine.
3. Tap Water Absorption
Grapes have porous skins. If they are washed or sprayed at the supermarket with highly chlorinated municipal tap water, the skin can absorb some of that odour.
If the grapes were slightly damp when packaged in plastic bags, the chlorine gas from the tap water gets trapped, concentrating the smell inside the bag.
Is it safe to eat them?
Generally, yes, provided you wash them correctly. The smell is usually a surface issue rather than a sign of internal rot.
How to get rid of the smell:
- Baking Soda Soak: Mix 1 teaspoon of baking soda in a bowl of cool water. Soak the grapes for 5–10 minutes.
- Vinegar Rinse: A 3:1 water-to-vinegar solution helps break down chemical residues and kills mold spores.
- Air Dry: After washing, let them sit out for a few minutes; many of the volatile chemical smells will evaporate.
