Left over from wallpapering. From a full 6 litres batch made today so nice and fresh.
It's in a plastic pot with a lid. Seems a waste just to get rid of it.
If you're local this is just what you need for that Bank Holiday papier mâché project :-)
As with all wallpaper pastes it contains a fungicide so use gloves with it, and best not to use it with small children who might lick their fingers or try to eat it...