Why does glycerol taste sweet?

Question

My family uses it as a moisturizer and my curiosity led to my discovery that it tastes sweet. It finally makes sense to me now that in Arabic, the name of this compound is "حَلَويْن", which translates literally to "sweet-yne".

I know that glycerol is a polyalcohol consisting of a hydrocarbon chain of three carbons, each of them bonded to a hydroxyl. Apparently, the high proportionality of OH- groups in glycerol to its mass is what gives it its moisturizing effect (hydrogen bonds with water). I am also aware that glucose (C6H12O6) contains hydroxyl groups as well..

Is this at all relevant to the fact they both taste sweet?

What explains the sweet taste of a polyalcohol?

Answer 1

It's a sugar alcohol.  

Answer 2

And that is why ethylene glycol (antifreeze) is so deadly to dogs. It tastes sweet, too. In the course of evolution, those who could detect these hydroxy groups must have had an advantage over those who could not. Sweetness = ripeness and  concentrated food energy, and of course we and the plants coevolved. They tell us when the fruit is ready to be dispersed by making hydroxy groups and we animals carry the seeds of the fruit away from the parent plant to a new location. Cool!