Noticing the difference from non washing to washing them.

I wash mine for 5mins in my thermomix in the simmering basket speed 5 with water level just covering the bottom of the basket.

I always add a dash of non filtered apple cider vinegar to mine.

If you don’t have a thermomix just grab a large bowl place grapes into the bowl. Fill with water to cover the grapes and add a dash of apple cider vinegar.
Gently move the grapes around with a spoon every now and then. And allow to soak in water for 5 mins.

Below is what the grapes looked like before washing, the water after and the grapes after the 5mins.

Before Washing

Water after Washing

After Washing