The Science Behind Wine Glass Shapes

• The more I learn about wine, the more I realise how little I know.

As my other half makes homemade wine, we drink a lot of wine that doesn't have the benefit of tasting notes on the label, or even a label at all. Part of the fun of the first bottle of a new batch is working out which glass is best to drink it from. To do this, we need some understanding of why wine glasses are different shapes.

There are four features to a wine glass which each serve critical roles. From the bottom to the top they are...

The base

The base quite possibly is the easiest of all the parts to understand. It makes sure the glass doesn't tip over. Don't cry over spilt milk, but spilt wine is another story.

The stem

The stem serves two distinct purposes.

The first is to allow the drinker to hold the glass without touching the bowl. If you hold a wine glass by the bowl you risk heating the wine from your body temperature. It's not ideal, especially for wines that need to be served cool or cold. If you feel your wine is too cold, cupping the bowl is the most effective way to warm the wine up.

The second is holding the glass by the stem will keep the drinker's hands away from the rim of the glass. Our hands have their own unique scent which most of the time is increased in intensity through the use of fragrant soaps, lotions and perfumes. These scents can overpower, mask or change the aromas from the wine so the design of the stem allows these scents to stay as far away from the drinker's nose as possible while still allowing for adequate control of the glass. Some professionals even go as far as to hold the base rather than the stem for this reason.

The bowl

The bowl of the glass is where the wine is settled.

The best glasses have a wider bowl than rim to allow for proper swirling. The swirl releases volatile aroma compounds and creates a vortex in the centre of the glass towards which these compounds are drawn. When the drinker then puts their nose in the glass after the swirl, they sniff in a concentrated amount of the aromas directly out of the glass. This allows for even the most nuanced of aromas to be detected.

The larger the bowl, the more surface area the wine can cover. The more surface area the greater amount of volatile compounds can be released. Keep in mind that a wine glass usually shouldn't be filled to more than one-third the total height of the bowl in order to have proper swirling room. Otherwise you risk losing your wine in a wild swirling accident and again, avoid spilt wine at all costs!

The rim

This rim is the point where the wine makes contact with the taster's mouth. The thinner the rim of the glass, the more seamless this transition is and the more the taster can focus on the perception of the wine in their mouth and less on the feel of the glass.

White wine glasses

White wines are typically served in smaller bowled glasses. 
Smaller glasses:

• Preserve floral aromas
• Maintain cooler temperature
• Express more acidity in wine
• Deliver more aromas (even at cooler temperatures) due to proximity to the nose

There are exceptions of course, full-bodied white wines like oak-aged Chardonnay, White Rioja, and orange wines are better with a larger bowl.

The larger bowl, originally introduced by Riedel as a “Montrachet” glass , better emphasises a creamy texture because of the wider mouth.

Red wine glasses

The choice of a red wine glass has a lot to do with mitigating the bitterness of tannin or spicy flavours to deliver a smoother tasting wine.

After a few years of tasting wines from different glasses, we’ve noticed that red wines tend to taste smoother from a glass with a wide opening. Of course, the distance to the actual fluid affects what you smell.

Large "Bordeaux" glass

This glass shape is best with bolder red wines, such as Cabernet Sauvignon, Cabernet Franc, Merlot or Bordeaux Blends.

• Delivers more aroma compounds vs. the burn of ethanol from being further from nose
• Larger surface area to let ethanol evaporate
• Wider opening makes wines taste smooth

"Burgundy" glass

A great choice for lighter more delicate red wines with subtle aromas. The large round bowl helps collect all the aromas. Try this glass shape with Pinot Noir, Gamay, Burgundy, Valpolicella blends, and even Nebbiolo!

As a general rules of thumb — a wider opening de-emphasises overpowering aromas; a narrower opening concentrates subtler ones.

And, of course, decant, decant, decant!

Andrew Rastello, the assistant wine director at Eleven Madison Park in New York, pours from a 200-page wine list into 17 different Riedel shapes. He says:

“For a customer to have a different glass for red Burgundy, versus Napa Cab, versus Bordeaux — it’s a luxury, but I believe it makes a drastic difference to the experience of the wine."