Leaving dishes overnight in the dishwasher should not ruin them. Dishwashers are designed to hold dishes for extended periods between cycles, and a short delay between running the dishwasher and unloading it should not cause any significant damage.
However, there are a few considerations to keep in mind:
Odor and bacteria: Leaving dirty dishes in the dishwasher for an extended period can result in odor and the potential growth of bacteria. To minimize this, it's best to scrape off excess food particles before loading the dishes into the dishwasher. If you are unable to run the dishwasher immediately, you can also rinse the dishes to remove any leftover food.
Stains and residue: Some food particles, particularly those with strong pigments or high acidity, may leave stains or residue on the dishes if left for too long. It's generally recommended to run the dishwasher within 24 hours to avoid any potential staining or difficulty in cleaning.
Moisture and mold: Extended periods of moisture can create a favorable environment for mold growth. If the dishes are not dried properly before loading them into the dishwasher or if the dishwasher has a prolonged delay between cycles, there is a slight risk of mold developing. To prevent this, ensure that the dishes are dry before loading them, and consider using the dishwasher's drying function if available.
In general, it is best to run the dishwasher as soon as it's full or within a reasonable timeframe to maintain cleanliness and prevent any potential issues. However, leaving dishes overnight in the dishwasher occasionally should not cause significant damage, as long as you take the necessary precautions to minimize odor, bacteria, stains, and moisture-related issues.