What Is the Alcohol Content of Rum Cake?

Wondering if rum cake is boozy? We break down alcohol by method, realistic per slice ranges, and simple rules of thumb, plus a quick calculator. Scroll to the bottom for the short answer recap.

A standard drink equals 14 grams of pure alcohol. That gives us a clean yardstick for real-world serving sizes, not just percentages.

Rum Cake Science

Alcohol does not vanish in the oven. How much remains depends on timing and heat exposure.

• Rum in the batter loses alcohol during the bake. Longer time at heat means less alcohol left, but it takes real time to drop meaningfully.
• Rum in a post-bake syrup keeps more alcohol, especially if the rum is stirred in off heat and the syrup is poured over a warm cake.

Those two steps explain why most recipes that both bake and soak end up near that quarter-drink-per-slice range.

A practical example

Picture a 10 to 12 slice Bundt. Use about 4 ounces of 80-proof rum in the batter and 4 ounces in a syrup that is heated, then the rum is stirred in off heat and poured over. After typical bake and soak steps, the whole cake often carries roughly three standard drinks total, which nets out to about 0.25 drink per slice.

What actually changes content?

• When the rum is added. Batter loses more during the bake. A post-bake soak retains more.
• Time and temperature. More time at heat lowers alcohol, but it does not drop to zero.
• Slice size. Same cake, smaller slices, less per serving.
• Resting and storage. Some evaporation continues as the cake rests, but it is not a magic eraser.

Baker forums and experienced home cooks agree that soak-style cakes taste “boozier” than batter-only versions. That lines up with what we see in the kitchen and with controlled cooking data. Batter reduces, soaks retain.

The everyday takeaway

If your rum cake uses rum in the batter and a warm syrup soak, expect about 0.2 to 0.5 drink per slice for a 10 to 12 slice cake, with most landing around 0.25. Batter-only cakes usually sit lower, often 0.1 to 0.2 per slice. Ingredients, methods, and resting time will nudge that number up or down.

Mini Calculator: Estimate Alcohol per Slice

This compact tool runs in plain HTML and JavaScript.

Short answer: Most classic rum cakes land around a quarter of a standard drink per slice when you bake rum in the batter and finish with a warm rum syrup poured on after baking. If you skip the syrup and bake all the rum into the batter, you are usually well under a fifth of a drink per slice.

FAQs

Does alcohol completely cook off in rum cake?

No. Some alcohol remains. The amount depends on bake time, temperature, and whether you add a post-bake soak.

Is there a single ABV number for rum cake?

Not a useful one. Cake is not a uniform liquid. Converting to standard drinks per slice is clearer.

Can one slice make you feel it?

Typical soak-style slices sit near a quarter of a drink. Most people will not feel noticeable effects from one slice. Heavy soaks or multiple slices will raise the total.