adapted from Kitchn
Yield: About 24 marshmallows, based on how you cut them
For the Bloom (the process of softening gelatin in cool liquid)
1 1/2 Tbsp unflavored gelatin
2 tsp vanilla extract
1/3 cup flat dark beer
For the Sugar Syrup
1/4 cup flat dark beer
1/2 cup plus 2 Tbsp corn syrup
3/4 cup granulated sugar
pinch salt
Coating and Topping
10-12 oz milk chocolate
2-3 tsp canola oil (for thinning the melted chocolate), optional
1/2 cup pretzels, crushed
The best beginning is starting the night before. Open the bottle of beer and let it sit overnight. If you forgot...pour the beer into a bowl. Whisk to release as much of the CO2 (carbon dioxide) as possible.
Line an 8 X 8 inch baking dish or an 8.5 X 4.5 loaf pan with parchment paper and then spray with nonstick spray. Tape the edges of the paper to the sides of the pan. This keeps the paper in place as you spoon in the mixture. Or, spray your baking pan with nonstick spray.
Preparing the Bloom
Sprinkle the gelatin in the bowl of a stand mixer. Mix the flattened beer and vanilla together. Pour the mixture over the gelatin. Allow the mixture to stand for three to five minutes. Whisk until no lumps remain.
Preparing Sugar Syrup
Combine the flattened beer, corn syrup, sugar, and salt in a 4-quart saucepan or larger. (We opted for the larger pan to avoid the overflow of any unforeseen excessive bubbling!) Attach a candy thermometer to the side. Turn the heat to medium high. Bring the sugar mixture to a boil. As the syrup heats it will foam up to the top of the pan. Keep watch! When the mixture is between 225° F. and 230° F., let it bubble for another 5 minutes and then remove from the heat. Ideally the syrup should reach 240° - 250° F, but you may have trouble getting an accurate reading due to the foam. If your syrup starts to climb to 250° F., remove the pan from the heat.
With the mixer on low speed, carefully pour the hot syrup mixture down the side of the bowl into the gelatin bloom. Turn the mixer to high and whip for 8-10 minutes, until it is very thick and looks like glossy meringue. Pour the marshmallow into the baking pan or loaf pan. Let it cure, uncovered, for 10-12 hours or overnight.
Preparing the Coating and Topping
When the marshmallows are cured, rub the top with a little powdered sugar. Turn the marshmallows onto a cutting board. Rub additional powdered sugar on the top. Cut the marshmallows into about 24 squares of equal size. The number depends on the size of square you desire.
Melt the chocolate over a double-boiler or in 30-second intervals on HIGH in the microwave, stirring between each interval until the chocolate is melted. Should the chocolate be too thick, whisk in the canola oil a teaspoon at a time until the chocolate is thin enough to coat the marshmallows.
Coat the marshmallows entirely by using a fork to lower the marshmallow into the chocolate and using a chopstick to turn the marshmallows in the chocolate. Lift the marshmallows out and set them on wax paper. Quickly sprinkle the tops of the marshmallows with crushed pretzels and a tiny bit of sea salt before they dry.
Marshmallows will keep in a covered container for several weeks.
NOTE: This is a recipe that takes time. The beer should flatten overnight. The marshmallows must cure in the refrigerator 10 to 12 hours or overnight. Just a note so that you allow yourself the needed time.