A whisky sour is whisky, lemon, and sugar, shaken hard with ice. Sometimes there is egg white. Sometimes there is a float of red wine. The question of which glass it goes in has two right answers, and the choice between them is not about taste in glassware. It is about whether there is ice in the glass when you serve it.
Served on the rocks, the drink goes into a short, wide rocks glass over fresh ice. Served up, with no ice in the glass, it goes into a stemmed glass: a coupe, or the old sour glass the drink once had to itself. This guide covers both, where each came from, how egg white foam changes the decision, how much glass the recipe actually needs, and what a cut rocks glass does for a pale, cloudy drink. It sits beside What Glass for a Manhattan and What Glass for a Negroni, which work through the same question for two stirred drinks.
The short answer
Use a rocks glass if you want ice in the drink. Use a coupe or a small stemmed sour glass if you do not. Both are standard. The International Bartenders Association gives both in the same recipe: strain into a cobbler glass, or, if served on the rocks, into an old fashioned glass filled with ice. Wikipedia lists the old fashioned glass as standard drinkware and the serve as on the rocks or straight up.
Simon Difford, in his history of the sour at Difford's Guide, puts it plainly: modern whisky sours tend to be served on the rocks in an old fashioned glass, but the same drink could be shaken and strained into a stemmed sour glass and served straight up. As long as the glass is the right size, he writes, pretty much anything goes.
Where the sour glass came from
The sour is older than the whisky sour. Difford's Guide records the first mention of a Sour in 1856, on a handwritten list of mixed drinks at a saloon in Toronto, and the first written recipes in Jerry Thomas's 1862 bar guide, for brandy, gin, and rum sours. Thomas told the bartender to use a small bar glass. The oldest known mention of a whisky sour, Difford notes, comes from a Wisconsin newspaper, the Waukesha Plain Dealer, on 4 January 1870, and it is mentioned as if no one needed it explained.
The Oxford Companion to Spirits and Cocktails explains why a dedicated glass followed. By the 1870s, whisky had moved into first place among the spirits used for sours. At the same time, bartenders began straining the drink into a separate glass instead of serving it in the one it was mixed in. That needed a new vessel. Like the cocktail glass of the day, the sour glass was stemmed, to keep the hand from warming it. It was larger, the Companion says, some 150 ml against the cocktail glass's 90 ml, to fit the citrus and the water that dissolved the sugar.
The glass kept changing after that. Difford traces George Winter's 1884 handbook calling for "a fancy sour glass" for some sours, William Boothby in 1908 straining sours into a highball or punch glass, and Charles S. Mahoney's 1912 Hoffman House guide giving the whisky sour a claret glass. A 1935 edition of the Old Mr. Boston bartender's guide, quoted on the blog Bourbon Veach, strains it into a Delmonico glass, the other common name for the sour glass, according to the reference site Dimensions.com.
The sour glass you can still find today is small and footed. Difford's Guide describes it as narrow at the stem and tapering out to a wider lip, holding about 3 to 5 oz, or 9 to 15 cl, to the brim.
Rocks or up: what changes in the glass
On the rocks
A whisky sour on the rocks is the longer, more forgiving drink. The ice keeps it cold as you drink it, and the water it gives up slowly softens the lemon. That is why it suits a rocks glass: a flat, heavy base, straight or gently sloped walls, and enough room for ice and the pour together.
The ice matters more than it does in a stirred drink, because a shaken sour arrives already diluted from the shaker. Several recipe writers, including the cocktail site 12x75, make the same point: strain over fresh, large ice, not the broken shards left in the shaker. One large cube melts more slowly than a handful of small ones, which keeps the balance where you set it. Our guide to large ice and the rocks glass covers fitting the cube to the bowl, and How to Make Clear Ice at Home for Whisky covers making it.
Up
Served up, the drink is shaken cold and strained into a chilled glass with nothing in it. It is shorter, sharper, and best drunk while it is still cold. A stem is the point here. With no ice in the glass, the hand holding the bowl is the main source of warmth, which is the same reasoning the Oxford Companion gives for the first sour glasses being stemmed.
A coupe is the practical choice for most homes: a shallow, wide bowl on a stem, and a glass you can also use for a Manhattan or a daiquiri. A small sour glass works the same way if you have one. Chill either with ice water while you shake, then tip the water out before you strain. More in Should You Chill Whisky Glasses.
Egg white, foam, and ice
The IBA lists egg white as optional, a few drops, and notes that when it is used the drink should be shaken a little harder to bring up the foam. Many bars and recipe writers use more, and shake twice: once without ice to whip the white, then again with ice to chill. The food site Cookie and Kate notes that the egg white version is technically called a Boston sour, though most menus still call it a whisky sour.
Foam is where the two serves pull apart. Cookie and Kate recommends serving the egg white version up in a coupe, because pouring it over ice cubes breaks up the foam.
A foamed sour still works on the rocks if you prefer it that way. Use one large cube rather than many small ones, so the foam settles on a flat surface of drink instead of catching on a pile of ice. Strain slowly, and let the drink rest for a moment so the foam rises into a single layer. In a rocks glass, the foam sits in a straight-walled ring at the top and the cube shows through beneath it.
If raw egg is a concern, 12x75 suggests carton pasteurised whites or aquafaba, the liquid from a can of chickpeas, at the same measure. Without foam, the rocks glass is the easy choice.
How much glass a whisky sour needs
The IBA specification is 45 ml of bourbon, 25 ml of fresh lemon juice, and 20 ml of sugar syrup. That is 90 ml of liquid before the shake. Shaking adds water, and egg white adds foam. The Oxford Companion's figure for the early sour glass, about 150 ml, shows how little room the drink needs when it is served up.
On the rocks, you also need space for ice. The Home Bartender glassware guide describes a double rocks glass, around 12 to 14 oz, as the size that fits a big single cube with room to spare, and that is plenty for a full sour. Too large a glass and the drink sits low, the foam spreads thin, and the cube looks stranded. Too small and the foam rides up to the lip. See also What Size Whisky Glass Do You Need.
The New York sour and the red wine float
The New York sour is a whisky sour with a float of dry red wine on top. The Oxford Companion dates the drink to the 1880s and first attests it to Chicago, where it was known by other names, including the Southern or Continental sour. The name New York sour, the Companion says, was in use in Boston as early as 1885.
Most modern recipes serve it in a rocks glass. The versions published by Liquor.com, from the distiller Allen Katz, and by PUNCH both strain the drink over fresh ice in a rocks glass and then pour the wine slowly over the back of a bar spoon so it settles on top. The Oxford Companion's own recipe strains it up into a chilled cocktail glass instead, and notes that egg white and ice both blur the sharp line between the red and the gold beneath it.
Either way, the glass needs straight, clear walls high enough to show the layer. That is a job a rocks glass does well. Pour the float last and serve it straight away.
Why a cut rocks glass suits a sour
A whisky sour is not clear. Fresh lemon juice clouds it to a soft, pale gold, and foam adds an opaque cap. In a plain glass, that reads as a flat yellow block. In a cut glass, the facets break it up. Where the cutter has opened a clear face in the wall, light passes through the drink and comes back brighter. Where the wall is cut into a fine lattice, the drink reads as a pattern of small lit points. The object is still. The light is doing the moving.
Colour changes the drink too. A deep overlay at the rim frames the foam with a band of colour. A clear foot lets the gold show at the base, where the drink is deepest. For a New York sour, a clear upper wall matters most, because that is where the red line sits.
A cut rocks glass also has the weight a shaken drink over ice wants. The heavy base keeps it steady on the table. For a longer look at how weight and cut work together, see Thin Tumbler vs Cut Rocks Glass.
A few common questions
Does a whisky sour go in a rocks glass?
Yes, when it is served on the rocks. The IBA gives an old fashioned glass filled with ice for that serve, and it is how most modern bars pour it.
Is a whisky sour served with ice?
It can be served either way. On the rocks it goes over fresh ice. Up, it is shaken cold and strained into a chilled stemmed glass with no ice.
What glass is best for a whisky sour with egg white?
A chilled coupe shows the foam best, because ice tends to break it up. If you prefer it on the rocks, use one large cube and strain slowly.
What is a sour glass?
A small footed glass, narrow at the stem and wider at the lip, made for sours served up. It is also called a Delmonico glass.
Glasses for a whisky sour on the rocks
- Cobalt Facet Whisky Glass: 201-300 ml, asa-no-ha lattice in the upper bowl and broad clear facets through the mid-body, so the pale gold of the drink reads through the blue.
- Pine Wind Whisky Glass: 201-300 ml, pine green at the rim with tall clear facets that drop through the mid-body like petals.
- Ruby Daisy Whisky Glass: 320 ml, deep ruby over the upper bowl, a row of clear oval scallops, and a clear foot where the drink is deepest.
- Smoke Flame Whisky Glass: 201-300 ml, smoke walls opened by broad diagonal clear facets over a thick base.
Each of these listings is Edo Kiriko: handmade crystal, hand-cut in Tokyo, as its product page states. View all glassware in Whisky Glasses.
Related reading: What Glass for a Manhattan: Coupe, Nick & Nora, or Rocks · What Glass for a Negroni: Rocks, Coupe, or Tall · Old Fashioned vs Rocks Glass