There are several molecular gastronomy techniques that have been developed to incorporate air into liquids and creams to make them lighter. The two most popular are probably airs and foams. But now, get your fish tank air pump ready! The “bubbles with air pump” technique produces a result similar to “airs” but with larger bubbles. I believe this technique was developed by molecular gastronomy Chef Grant Achatz of Alinea in Chicago.
Airs are usually made by adding soy lecithin powder to a liquid and incorporating air using an immersion blender on the surface of the liquid. Foams are made by whipping or using an N2O siphon such as the ISI Whip with a liquid with high fat content (cream), egg whites, versawhip or methylcellulose to name a few.
The “bubbles with air pump” technique consists of injecting air using a fish tank air pump into a liquid with some viscosity. It works great with light syrups and juices by just adding a little egg white powder and Xanthan gum.
One of the advantages of this technique is that you can just leave the air pump running all the time so you always have bubbles ready to be served. Another interesting way of applying this technique is to fill the bubbles with smoke or herb, flower or spice vapor so the aromas are released when the bubbles burst.
If you don't have a fish tank air pump you could use for this, I recommend buying the inexpensive and silent Tetra Whisper Air Pump.