If you want to see something surprising, add something alkaline to a red wine stain – you’ll see it turn blue.
This is just another example of a pH-dependant colour. Unlike the beetroot, however, one of the colours is not clear.
So we have to be a little more aggressive, and in this case it means oxidising the stain to bits. We could use bleach for that, but that’s far too aggressive and damages fabrics.
So we’ll use Preen Oxy-Action. It contains peroxide. Just spray it onto the stain, wait a couple of minutes and you’ll see it disappear before your eyes. Then just throw it in the wash and the job’s done.