Yes — use rum instead of bourbon 1:1 in baking. The recipe asks for bourbon — a pecan pie, a chocolate cake, a bread pudding — and you have rum. The swap is 1:1 in baking, and it is one of the easiest in this family, because both are dark, sweet, barrel-aged spirits. What changes is the accent: vanilla and oak give way to molasses and dark fruit.
How much rum to use
| Bourbon in the recipe | Rum to use |
|---|---|
| 1 tbsp | 1 tbsp |
| 2 tbsp | 2 tbsp |
| 1/4 cup | 1/4 cup |
| 1/3 cup | 1/3 cup |
| 1/2 cup | 1/2 cup |
| 3/4 cup | 3/4 cup |
| 1 cup | 1 cup |
The ratio is 1:1 in baking. All amounts above are approximate — measure with a tablespoon or a measuring jug, and taste as you go.
Worked example 1: a pecan pie
A pecan pie asks for 2 tablespoons of bourbon in the filling. Use 2 tablespoons of dark rum instead and the pie will be a little sweeter and fruitier, with a molasses depth that suits pecans very well. The bourbon's vanilla and oak are gone, but the rum's caramel notes fill the same space, and most people will not be able to tell which spirit you used. This is the swap's best case: a rich, sweet filling where either spirit is an accent, not the star.
Worked example 2: a chocolate cake
A chocolate cake asks for 1/4 cup of bourbon in the batter. Use 1/4 cup of dark rum instead and the cake will be a touch sweeter and a touch fruitier, with the rum's molasses leaning into the chocolate's bitterness. It works beautifully, because chocolate is a strong flavour that welcomes either spirit. If the cake is very dark chocolate, the rum is arguably the better choice.
Worked example 3: the wrong recipe — a bourbon caramel sauce
A caramel sauce asks for 1/4 cup of bourbon, and the bourbon is the flavour the sauce is named for: its vanilla and oak are the point, and the sauce is served in small amounts where that flavour is front and centre. Rum makes a good caramel sauce, but it is a rum caramel sauce, not a bourbon one, and anyone who ordered bourbon caramel will notice. The lesson is that a swap is free when the spirit is an accent, and it is a different dish when the spirit is the name.
What changes when you use rum
Flavour depth is what changes, not volume. Spirits swap 1:1 in baking, where the alcohol mostly bakes off and leaves behind caramel, vanilla and oak notes, but each spirit leaves a different fingerprint. Rum is sweet and molasses-rich, with a warm, dark fruit character that suits fruit cakes, chocolate and anything with brown sugar. Bourbon is drier and spicier, with vanilla and oak from the barrel, and it leans into pecan, chocolate and caramel. Extracts are a different animal altogether: they are concentrated flavour without the alcohol, so a tablespoon of extract stands in for a quarter of a cup of liquor, and they cannot carry flavour through a long bake the way real spirits do. The second change is moisture — a quarter cup of rum adds liquid that a tablespoon of extract does not, so a batter can end up slightly drier when you go the extract route. The third change is cost and keeping: a bottle of rum lasts years in the cupboard, while an open extract loses strength over time.
When not to substitute
Do not use rum where bourbon is the named flavour — bourbon caramel, bourbon balls, and anything where the bottle is the point. Do not use a light rum here: dark rum is the only good match, because light rum is too thin. And do not use rum in a dish where bourbon's dryness matters, such as a savoury bourbon glaze for ham, where rum's sweetness can tip the balance.
Method and source
The ratio comes from the CookScale substitution data, which records that extracts are concentrated — one tablespoon of extract replaces about a quarter cup of liquor — and that spirits swap 1:1 in baking. This is a volume swap, so no density figure applies. Treat the result as approximate: rums vary from light and grassy to dark and syrupy, and bourbons vary in sweetness, so the same swap can taste different from one bottle to another. The data warns not to use an extract where the liquor is the main flavour, because the alcohol carries flavour that extract cannot, and that is the rule that decides most of these swaps. In a fruit cake that simmers in rum for weeks, there is no extract substitute at all.
Practical guidance
Buy a small bottle of dark rum and a small bottle of bourbon and keep both for baking — they last for years and a little goes a long way. Measure spirits with a tablespoon, not by eye, because a free pour easily doubles the amount and can make a batter too wet to set. If a recipe asks for rum and you are baking for children, remember that most but not all of the alcohol bakes off; a cake baked for an hour keeps very little, but a rum butter sauce added at the end keeps much more. Extracts belong in the fridge door once opened, and if one smells flat, it is. When a recipe says flambé, never substitute an extract — it will not ignite, and the dish will miss the whole point.
Use dark rum, not light, and keep the amount the same — 1:1, no maths needed. If the recipe is a sweet filling, the rum's extra sweetness is an asset; if it is a savoury glaze, add a squeeze of lemon to keep it from tasting too sweet.
Buying and storing
A bottle of rum or bourbon keeps for years in the cupboard, even once it is open, because the alcohol preserves it — so buy a small bottle and it will last through dozens of bakes. Store it upright, away from heat and light, and keep the cap on tight, because alcohol evaporates and a half-empty bottle loses strength over time. Extracts are the opposite: an open bottle of rum extract loses its strength within a year, so buy the smallest bottle you can and keep it in the fridge door. If an extract smells flat or weak, it is, and no amount of extra extract will fix a cake — buy a fresh bottle.
Frequently asked questions
Can I use rum instead of bourbon in baking?
Yes, 1:1, and it works very well in most baking. Dark rum is the right match — it brings molasses and caramel notes where bourbon brings vanilla and oak. The dish will be a little sweeter.
Is rum or bourbon better in pecan pie?
Both are excellent. Bourbon is drier and more oaky; rum is sweeter and fruitier. Most bakers would be happy with either, and the pecans and brown sugar do most of the work.
Can I use rum instead of bourbon in a chocolate cake?
Yes, 1:1. Rum's molasses character leans into dark chocolate very well, and many bakers prefer it. Use dark rum for the best result.
Does rum work instead of bourbon in a savoury glaze?
It can, but rum is sweeter than bourbon, so a savoury glaze can tip too far towards sweet. Add a squeeze of lemon or a splash of vinegar to balance it.