Single Rocks Glass: 6–9 oz

The standard rocks glass — also called an old fashioned glass — is the everyday size for a neat pour or whiskey on the rocks. It's smaller and more proportionate in the hand than a double old fashioned, with a heavy base and straight sides built for a single large ice cube or a couple of standard cubes. If you only own one whiskey glass, this is probably it.

Double Old Fashioned (DOF): 12–14 oz

The double old fashioned — often abbreviated DOF — is the larger sibling of the standard rocks glass, typically in the 12–14 oz range. Our own 13.5oz rocks glass sits right in this category. The extra capacity exists mainly for ice: the DOF is built to accommodate the large single ice cubes and spheres that have become standard in modern craft cocktail culture, since a single large cube melts slower and dilutes the drink less than several smaller ones. It's also the more practical choice for cocktails that involve muddling or stirring, which is why it's become the more common size in bars and home collections despite being less traditional than the single rocks glass.

Single rocks glass — 6–9 oz.

Double old fashioned — 12–14 oz, built for large ice.

Glencairn glass — 6–6.5 oz, built for nosing.

Glencairn Glass: 6–6.5 oz

The Glencairn is a different category entirely — a nosing and tasting glass rather than an everyday drinking glass. It was designed by Raymond Davidson of Glencairn Crystal, drawing on the shape of a traditional sherry copita, and debuted publicly at WhiskeyFest in Chicago in 2001. Despite its 6–6.5 oz overall capacity, a typical tasting pour is closer to three-quarters of an ounce.

The shape does real sensory work: a bulbous bowl lets you swirl the whiskey, and a tapered, chimney-like top funnels the aroma toward your nose while venting off sharper alcohol fumes — which is why it's endorsed by the Scotch Whisky Association and shows up on tasting panels far more than at a casual bar. It's also stable enough to tilt and roll for examining color and legs without spilling.

Quick Comparison

If you're buying a gift and aren't sure which to choose: the double old fashioned is the safest general-purpose pick for most whiskey drinkers, while a Glencairn is the better choice specifically for someone who cares about tasting and nosing over casual sipping.

Frequently Asked Questions

What's the difference between a rocks glass and a double old fashioned glass?

Mainly size. A standard rocks glass runs about 6–9 oz, while a double old fashioned is roughly 12–14 oz — built with the extra capacity to accommodate large ice cubes or spheres without overflowing.

Why is a Glencairn glass smaller if it's meant for "serious" whiskey drinking?

The Glencairn is designed for nosing and tasting rather than a full casual pour — its tulip shape concentrates aroma toward the nose, so a smaller working volume (around three-quarters of an ounce per pour) is actually the point, not a limitation.

Can I use a double old fashioned glass for cocktails, not just whiskey?

Yes — its larger capacity and sturdy base make it a common choice for whiskey cocktails that involve muddling or stirring, like an actual Old Fashioned or a Negroni, in addition to serving whiskey on the rocks.

Is a bigger whiskey glass always better as a gift?

Not necessarily — it depends on the recipient. A double old fashioned suits most everyday whiskey drinkers, but a whiskey enthusiast focused on tasting and nosing single malts will likely get more use out of a Glencairn.

All three sizes have a legitimate place on a home bar — the single rocks glass for everyday pours, the double old fashioned for cocktails and modern ice, and the Glencairn for genuinely tasting what's in the glass. Personalizing whichever one fits the occasion just makes it a better gift.