When vinegar is added to hot milk and stirred for a while, it leaves behind lumpy blobs, which float up to the top after cooling.
When vinegar is added to hot milk and stirred for a while, it leaves behind lumpy blobs, which float up to the top after cooling. They can be moulded into different shapes and will harden in a few days. This happens because milk contains a protein called casein. Vinegar is an acid and when added to