(Forbes) - Chilean love poet Pablo Neruda kept an array of multi-colored glasses at his beach house in Isla Negra, believing their color impacted the taste of his wine.

The effect of color on taste relates to psychology. However, the way the shape of a glass impacts taste relates to physics. Well, almost.

Unlike a martini glass (which slopes outward), or glasses with vertical sides, the sides of a wine glass bow inward toward the rim. Unlike other shapes, this concentrates alcohol aromas around the rim. This means that when we point our nose toward the center of a glass, the harshness of gaseous ethanol, or alcohol, is reduced, making wine aromas more distinct.

We know this because, according to a 2015 report in Chemistry World, Japanese researchers mapped this concentration distribution of alcohol leaving a glass and found that both temperature and shape impacted this invisible flow.

The intensity of wine aromas also strongly correlates with the ratio between the diameter of the glass cup (the widest part of a glass) to the diameter of the opening.

But how does shape impact taste?

When you drink, you tilt your head differently, depending on the shape of your glass. With wide rimmed glasses, you lower your head, but when drinking from narrow rims you tilt your head back. These different positions change the speed of wine hitting your tongue, as well as where it hits.