There are many different types of foams you can make using different modernist ingredients and foaming methods. This foam resembles bubbles and is made with xanthan gum and Versawhip that has been aerated with an aquarium pump. It's a pretty unique way to make bubbles and they are very interesting.
These bubbles are large and visually interesting. They also carry a surprising amount of flavor. I originally wanted to make these to use with a peanut butter panna cotta for a take on a PB&J but it can be used on many different dishes. You can also substitute the grape juice for just about any other fruit or vegetable juice.
If you like this recipe you can get more than 80 other recipes from my book Modernist Cooking Made Easy: Getting Started. The book covers many of the popular modernist techniques such as gelling, spherification, and foams. It also explores modernist ingredients like agar, sodium alginate, tapioca maltodextrin, and xanthan gum. It is all presented in an easy to understand format and I think it's the best way to learn about modernist cooking.
Also, if you are just getting started experimenting with molecular gastronomy and modernist cuisine then I highly recommend one of these molecular gastronomy kits. They have everything you need to do many different dishes.
1.0 grams xanthan gum, 0.25%
Combine the grape juice with the Versawhip in a narrow, deep container and blend with the immersion blender to combine. Add the xanthan gum and blend until it is evenly distributed. You can set the mixture aside like this for several hours.
When ready to serve, connect a clean piece of plastic hosing to the aquarium pump and place the other end in the mixture. Turn on the pump and let it create bubbles until there are enough for you to use.
Let the bubbles sit for 1 minute to stabilize and then spoon them out onto your dish.