Think you know the right way to pour a glass of wine? Take a look at the four glasses and choose the one you think is filled correctly before reading the answer. While they all contain wine, only one is considered the ideal pour. Many people assume a fuller glass is better, but wine is meant to be enjoyed differently.

The correct answer is Glass #3. It may not look as full as the others, but it actually contains the ideal serving. Wine glasses are designed with a wide bowl so the wine has room to interact with the air, allowing its aromas and flavors to develop. The extra space also lets you swirl the wine gently without worrying about spills.

Glass #4 is filled too high, leaving almost no room for swirling or releasing the wine’s aroma. Glass #1 contains too little wine and resembles a tasting sample rather than a normal serving. Glass #2 is closer to the ideal, but it still fills the glass more than experts generally recommend for most wines.

A standard serving of red wine is about 5 ounces (150 ml), which usually reaches the level shown in Glass #3. Filling the glass only partway improves the tasting experience by giving the wine room to breathe and making it easier to appreciate its aroma. So, if you want to pour wine like a pro, remember that leaving a little empty space is actually part of serving it correctly. Did you guess the right answer?