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I own two of your books, but have not yet succeeded in certain techniques. For one, I'd like to make some intensely flavored vegetable bubbles, e.g. celery bubbles, or foam. If I simply boil celery in water and reduce it, I don't get much flavor.
Then adding to this watery liquid xanthan gum and versawhip at the high end of the range of ratios you suggest results in no bubbles or foam, either using the aquarium pump or the whipping siphon. What's the right way?
Thanks, Dave McA
Hi Dave, that's a really good question. There's a few different ways to make vegetable bubbles and foams but there are basically two components to master: extracting the flavor from the vegetables and creating the foam itself.
You have several options when trying to create flavorful liquids based on fruits and vegetables.
If you have a juicer, that's the easiest way to get pure, really strong liquid out of vegetables. Simply run the vegetables through the juicer to pull out the liquid. You can also roast or grill the vegetables first for added flavor.
I've had very good success using a juicer for cucumbers, peppers, carrots, apples and even green beans. I know Alinea makes a celery juice by blanching celery in salt water for 30 seconds then juicing it.
This is often the method I'll turn to make flavorful vegetable liqiuds. You can either use a blender or food processor to puree the vegetables directly (adding water if needed) or for harder vegetables, you can first cook them before pureeing. To cook them, you can either roast or grill them, or for a more pure flavor you can steam or boil them in a small amount of water.
If you are going to create a foam from the liquid or want a more refined flavored you should strain the solids out of the puree before foaming.
For a more concentrated, flavorful liquid, I've found that a pressure cooker is a great way to go. It really breaks down the vegetables and extracts all their flavor. You can also add some baking soda if you want the vegetables to caramelize.
Sample Recipe: Pressure Cooked Carrot Soup
Another way to create flavorful vegetable liquids is by creating an infusion. Simply heat up some water or other liquid with the vegetables in it, then let them steep for 20 to 30 minutes.
This works best for very strongly flavored vegetables. I've used it with great success for chile peppers, horseradish, ginger, and herbs. You can also make infusions in the whipping siphon, which can extract even more flavors.
Sample Recipe: Orange-Cinnamon Infused Bourbon
When making a flavorful liquid out of vegetables there are a few things to keep in mind.
The amount of flavor in the vegetable makes a big difference when creating flavored liquids. It's a lot harder to make a really strong celery liquid than a really strong habanero pepper liquid. For milder vegetables you want to make sure you're using as little liquid as possible and are maximizing the extration of flavor, either through heating or pureeing.
You need a certain amount of liquid when making foams or gels. You can't foam a coarse paste, it has to be a watery liquid. Some vegetables have a lot more water in them to start with and the flavors can be extracted more easily.
Things like bell peppers, cucumbers, watermelon, and other water-based vegetables probably will not need any additional liquid added. Dry vegetables like potatoes, carrots, and beans will need more water or liquid added to them.
Once you have the flavorful liquid you can foam it in all the usual ways. The main types of foams are:
These are very light and dry foams and can be hard to use with vegetable-based liquids. Because they are so dry, very little flavor is actually contained in the foams. They are best made with very strong liquids like vinegars, soy sauce, and hot sauces.
These foams are denser than the airs and bubbles and contain more flavor. They work with most vegetable liquids, though the flavor of some of the blander vegetables don't stand out as much. They are typically made with an immersion blender or, more commonly, a whipping siphon.
Sample Recipe: Blueberry Froth
Dense foams are full of flavor and can be made from any vegetable-based liquid. They're usually the texture of whipped cream and can carry even the blandest flavors. They are made with a whipping siphon or electric whisk.
Creating flavorful foams from vegetables is definitely possible once you understand the basic steps in the process. What are your favorite vegetable foams and how do you go about making them? Let us know in the comments below!