The most unsatisfying taste is probably lukewarm tap-water, amirite?

Stick your finger in your ear then lick your finger.

Lukewarm tap water is my primary source of water. I don't generally like cold things. I never put ice in my drinks. I drink warm beer and don't chill white wine.

What about your own lukewarm saliva. Your mouth already tastes like it. So you wouldn't perceive a change in taste.

Re-frozen melted ice cream

Have you ever tasted Sunny Delight?

Especially if you live in Flint, Michigan.

Melt icecream. Melt to the point you can't do anything but to eat it.

Have you tasted Dasani?

Piss?

Not when you are hungover