How to make culinary foam

May 7, 2007 1:35 PM

How do I make culinary foam?

I'm experimenting with some ideas culled from molecular gastronomy, and I'm having a tough time getting my foam to work. I'm using agar-agar and a whipper, but I can't seem to get it right. What is the right ratio of agar-agar to liquid? What are the right steps for producing foam with a good body to it? Any experienced advice would be greatly appreciated.

posted by rush to Food & Drink (9 answers total)

A whipper meaning a handheld mixer, or meaning an N₂O siphon? Using the latter, I've never had any recalcitrance from my foams, as long as there's a little fat in the liquid.

You can also try whipping a liquid with a stick blender and skimming off the resulting foam topping -- I believe technically that's an air.
posted by Eater at 2:18 PM on May 7, 2007

Best answer: If nobody pops in with a long detailed answer, you want Chapter 11 of On Food and Cooking. I'm not at home right now, or I'd look it up for you, but your library is bound to have it.
posted by LobsterMitten at 2:45 PM on May 7, 2007

I was just musing with a friend if you could use the new foaming handsoap dispensers to do this. You know, washed out of course, and with a liquid-enough base material (carrot juice, for example).
posted by cocoagirl at 3:35 PM on May 7, 2007

I believe Eater's got it. Nitrogen siphons are the way to go (the one by iSi is very popular), or you can get a less stable version with a stick blender. With a good siphon, you won't need the agar with a lot (or even most) liquids.
posted by mostlymartha at 3:53 PM on May 7, 2007

Best answer: Whippers are what iSi calls their "foamers."

Have you tried watching iSi's tutorial videos? They have some sample recipes and problem-solving tips there.
posted by junesix at 4:04 PM on May 7, 2007

In the good old days (as a kid) you just stuck an egg beater into cooled JELL-O Gelatin liquid and produced lots of fine froth that would set up in the fridge. While it was crap it was much better than the Miracle Whip crap.

Whats with this agar-agar and nitrogen nonsense? Foam can be created and worked with old-school gelatin. If you don't have the skillz to do this then all you are looking for is the latest technique which seems to be much more difficult, I guess because it is the latest.
posted by MonkeySaltedNuts at 5:39 PM on May 7, 2007

You can "make" foam with a stick blender, but for it to hold, you need a gelatin. Lecithin is quite common and is easy to find at supermarkets and GNC (it's used for nutritional supplements/drinks, I guess). This is what restaurants will normally use.

Egg beaters won't be as efficient as a stick blender, but will probably work. With a stick blender, just hold it at an angle, so only half of the blade end is in the liquid, then blitz away and you'll have foam. Just be careful when skimming the foam that you don't get any liquid.
posted by BradNelson at 10:07 PM on May 7, 2007

Is your name Marcel from this season of Top Chef on Bravo? :)
posted by santojulieta at 5:16 AM on May 8, 2007

Response by poster: Thank you to everyone for their help - I think I've got it now. It was a combination of learning more about how the agar actually works (thanks, LobsterMitten), combined with one of the troubleshooting tips on the iSi site (thanks, junesix).

Temperature!
posted by rush at 8:15 AM on May 8, 2007