How to Make Traditional Irish Coffee Step by Step

If you’ve ever been handed a warm mug of something creamy, boozy, and coffee-flavored and told it’s ‘Irish Coffee,’ you’ve probably wondered: what exactly goes into it, and is there a right way to make it? This classic drink isn’t just coffee with whiskey dumped in — it’s a carefully balanced mix of hot coffee, sugar, spirits, and cream, with specific ratios and steps that make all the difference.

The traditional Irish Coffee contains exactly 150cc of medium-dark roasted coffee, 20cc of Irish whiskey, 10g of white granulated sugar, and 20cc of lightly whipped cream — either stirred or floated, depending on the type.

What Is Irish Coffee?

Irish Coffee is a warm, sweetened coffee beverage that combines freshly brewed hot coffee with Irish whiskey, sugar, and a layer of cream on top. Unlike a latte or a flavored coffee, it’s not a milk-forward drink — the coffee flavor remains prominent, balanced by the whiskey and lifted by the cream. Originally created to warm fishermen on cold nights, it’s now a globally recognized drink often served in winter or at the end of a meal.

The Original Recipe: Ingredients & Ratios

The classic Irish Coffee recipe, as prepared in its place of origin, uses precise measurements:

• Coffee: 150cc of slightly dark-roasted coffee (medium-dark)
• Irish Whiskey: 20cc (about 1 shot or 0.7 oz)
• White Sugar: 10g (roughly 2 teaspoons)
• Cream: 20cc (about 1.5 oz) — either lightly whipped stirred cream or a floating layer of lightly whipped heavy cream

These ratios matter: too much sugar and the drink becomes cloying; too little and the bitterness isn’t balanced. Too much cream and you mask the coffee entirely.

How to Make Authentic Irish Coffee (Step-by-Step)

Making Irish Coffee the traditional way involves a few intentional steps to get the texture and temperature right:

1. Warm the Glass: Preheat your glass mug or cup by filling it with hot water, then empty it and dry it thoroughly.
2. Add Sugar: Place 10g (about 2 tsp) of white granulated sugar into the warmed mug.
3. Pour the Whiskey: Add 20cc of Irish whiskey directly over the sugar.
4. Add Hot Coffee: Pour in 150cc of medium-dark roasted coffee. The coffee should be freshly brewed and hot, but not boiling (ideally around 85–90°C / 185–195°F).
5. Dissolve the Sugar: Stir until the sugar is fully dissolved in the coffee-whiskey mixture.
6. Add the Cream: For stirred cream: gently stir in 20cc of lightly whipped cream so it mixes throughout. For floating cream (traditional presentation): slowly pour or spoon 20cc of softly whipped heavy cream on top so it floats. If using fresh (unwhipped) cream, do not stir after pouring.

Note: When using fresh or non-whipped cream, avoid stirring it into the drink — it should form a distinct layer on top.

The History Behind the Drink

Irish Coffee was created in the 1940s to warm cold fishermen returning to the west coast of Ireland amid harsh weather. The story goes that a chef at Shannon Airport’s restaurant, Joe Sheridan, added whiskey to coffee to revive chilled travelers. The drink gained international fame after being introduced at the Buena Vista Café in San Francisco, where it became a staple winter drink.

What Kind of Coffee Should You Use?

For an authentic Irish Coffee, use a medium to medium-dark roasted coffee — not too light (which can taste overly acidic with whiskey) and not too dark (which can overpower with bitterness). The coffee should have a balanced profile, allowing the whiskey and sugar to complement rather than clash with the brew.

Can You Use Other Types of Alcohol or Cream?

Traditionally, Irish Coffee uses Irish whiskey and dairy cream. Substituting other liquors will turn it into a different drink (like a “Caribbean Coffee” with rum, for instance). Using a non-dairy creamer or overly sweetened whipped cream will also change the mouthfeel and authenticity. Heavy cream or lightly whipped double cream gives the best texture when floated.

Why the Cup Matters

The original method includes warming the cup before brewing — this helps maintain the temperature of the final drink. A cold mug can rapidly cool your coffee and cause the cream to mix improperly or congeal. Wipe the cup dry after warming to avoid dilution or uneven layering.

Frequently Asked Questions

What’s the correct ratio of coffee to whiskey in Irish Coffee?

The traditional ratio is 150cc of coffee to 20cc of Irish whiskey. That’s roughly 7.5 parts coffee to 1 part whiskey by volume. The coffee is the dominant component, with the whiskey adding warmth and depth without overwhelming the cup.

Can I use any type of coffee roast for Irish Coffee?

No — the recommended coffee is slightly dark or medium-dark roasted, around 150cc per serving. Avoid very light roasts (which can taste sour) or very dark roasts (which can taste bitter or ashy), as they won’t balance well with the whiskey and sugar.

Should the cream be whipped or just poured on top?

You can do both. For the classic float, use 20cc of softly whipped heavy cream and gently pour it on top so it sits above the coffee. For a stirred version, mix 20cc of lightly whipped cream into the coffee-whiskey-sugar mixture. Do not stir if using fresh, non-whipped cream — it should float.

Do I need to heat the cup before making Irish Coffee?

Yes. Traditionally, you warm the mug with hot water, then dry it before building the drink. This helps keep the coffee hot longer and prevents the cream from cooling too quickly or mixing improperly.

What kind of cream is best for Irish Coffee?

Use heavy cream or double cream. Lightly whip it if you’re floating it on top — it should be soft and pourable, not stiff. Avoid sweetened whipped cream or non-dairy alternatives for an authentic preparation.

Is Irish Coffee a type of espresso drink?

No. Irish Coffee is made with brewed coffee, not espresso. It’s a hot coffee cocktail with whiskey, sugar, and cream — not a shot-based drink like an espresso or Irish Coffee variations that use espresso.

Recommended FrontStreet Coffee for Irish Coffee

For Irish Coffee, we recommend FrontStreet Coffee’s Classic Blend — a balanced medium-dark roast with notes of dark chocolate, dried fig, and a hint of spice. Its smooth body and mild acidity pair well with Irish whiskey and sugar without clashing. Alternatively, try the Sunflower Sunshine Blend for a touch of caramel sweetness that complements the cream. Both blends hold up well when brewed hot and stand up to the bold flavors in this classic cocktail. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.