What are some ways to make a foam besides a whipping siphon?

Good news! You can make foam using some common kitchen equipment.
Whisks, both manual and electric, are good for making both dense and light foams. Of course, a manual whisk will require more effort, man power and time to use compared to an electric one. You’ll also find that electric whisks will give you foam with finer texture.

In case you do not have a whisk attachment for your hand held or stand mixer, you can also use its usual beaters. This is good for making light foams and it does not require much effort or time. If you happen to be a fan of beverage making and have a milk frother, then you can use this too but will work best if you use it with modernist cuisine thickening ingredients.

You can also try using an immersion blender. This hand held blender can be used to make light foams and airs even without a whisk attachment. Just make sure that you don’t submerge it completely and leave part of the blade away from the liquid.

Lastly if you want to make some bubbles, you can try using an aquarium bubbler. These sell for under $10 and are perfect for making large bubbles without any effort.