There is a specialist tea shop in Liverpool called (unsurprisingly) the Mersey which can provide any sort of tea. If it's out there then Mersey has it. One day a man goes into the shop and asks to try their rarest tea. He is told that this is the famous Australian Koala tea from Coober Pedy and that he would be welcome to try a cup.
He is presented with a cup of dark but cloudy tea. The man finds it very palatable but there is something wrong with the texture. He is distreessed to find bits of hair and other unidentifed lumps in it so he points this out to the shop,s owner. The owner replies
"Surely you know that the Koala tea of Mersey is not strained."