Homemade Toasted Marshmallow Soda, 63 Cents
The first cold weekend of November is bonfire season, and the drink I want next to a fire is the one that tastes like the thing you are toasting over it. This toasted marshmallow soda is a two-step build: scorch a pan of marshmallows, melt them into a brown-sugar syrup, and pour it over sparkling water with a splash of cream. It tastes like the crust of a s'more, and at my local prices the whole batch of eight glasses costs $5.04.
The syrup (makes about 1.5 cups, 8 servings)
- 8 oz marshmallows (most of a 10 oz bag), plus a few more for garnish
- 1 cup granulated sugar
- 0.5 cup brown sugar, packed
- 1 cup water
- 1 tsp vanilla extract
- A pinch of salt
Spread the marshmallows on a parchment-lined sheet pan and broil for 1 to 2 minutes, watching the whole time, until the tops are deep golden brown. Some dark edges are the point; black all over is burnt sugar, and it will read bitter in the glass. Scrape everything, toasted tops and all, into a saucepan with the sugars, water, and salt. Simmer 4 to 5 minutes, stirring, until the marshmallows fully melt. Off the heat, stir in the vanilla. The syrup will look thin hot and thicken as it cools.
Per the FDA's guide to storing food safely, refrigerate syrups promptly in a clean, covered container; I keep this one up to a week, and the FoodKeeper guidance is the reference I check for anything I plan to hold longer.
The build, glass by glass
Fill a 16 oz glass with ice. Add 3 tablespoons of syrup, pour in 8 oz of well-chilled sparkling water, and stir once, gently, so you keep the fizz. Float 1 tablespoon of half-and-half on top and finish with a marshmallow you toasted over the fire, or under the broiler, on a skewer. If you liked the technique in our vanilla cream soda comparison, this is the same syrup-first method with a toasted top note doing the work the vanilla did there.
What it costs
Prices are my local shelf prices this week, the same convention I used in the grapefruit soda myth test.
| Ingredient | Batch cost |
|---|---|
| Marshmallows, syrup + garnish (about 9 oz of a 10 oz, $1.24 bag) | $1.12 |
| Granulated sugar, 1 cup | $0.48 |
| Brown sugar, 0.5 cup | $0.36 |
| Vanilla extract, 1 tsp | $0.40 |
| Sparkling water, 2 litres | $1.98 |
| Half-and-half, 1 cup total | $0.68 |
| Salt and water | $0.02 |
| Batch total (8 glasses) | $5.04 |
| Cost per glass | $0.63 |
Figure 1: Cost per glass at the author's local prices. Canned and cafe prices are the author's local shelf and menu prices, November 2026.
Three things that go wrong, fixed
The syrup seizes into candy threads. Your marshmallows were toasted too dark or the pan was too hot. Keep the simmer gentle and stir constantly; the marshmallow dissolves rather than fries.
The drink tastes flat-sweet. It needs acid and salt, not more sugar. The pinch of salt is already in the syrup; add a squeeze of lemon (about 1 teaspoon per glass) and the whole thing wakes up.
The cream curdles into flecks. Your lemon went straight onto the cream. Stir the lemon into the soda first, then float the cream last, and it stays smooth.
Two variations worth the jar space
Salted version. Add a second pinch of flaky salt to each glass and skip the cream. The drink turns from dessert toward something closer to a salted caramel soda, and it pairs better with actual food.
Hot version. Stir 2 tablespoons of syrup into 8 oz of hot milk for a toasted marshmallow steamer. It is the same jar of syrup doing a completely different job on a cold night, which is exactly why I make a double batch.
Make the syrup on Sunday, keep it in a jar, and you have a bonfire drink, a Thanksgiving-week dessert soda, and a very good use for the half bag of marshmallows already open in the pantry, all week, for about the price of one cafe glass.
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