What is an Emulsifier?

So asks reader Wale, and it’s just the sort of question I like to answer on a Wednesday morning. The short answer is that an emulsifier is a substance that keeps an emulsion stable. But then what exactly is an emulsion again?

Emulsions are combinations of liquids that don’t normally like to be combined. In the kitchen those liquids are usually oil (or melted fat) and water. Like the members of Arcade Fire and the Flaming Lips, they don’t like to mix with each other very much, yet they can be made to with effort. Shake a jar containing water and olive oil vigorously and you’ll get an emulsion: millions of tiny oil droplets inside the water phase. The problem is that it won’t last very long. After about a minute or so the oil droplets start to recombine and the two phases separate again.

What to do? Well it turns out that certain other compounds that can be added to an emulsion to keep it from breaking — to stabilize it, in other words. Lots of different types of molecules can be used as emulsifiers in an oil-and-water emulsion, but what they all have in common is that one end of them is water-loving (hydrophilic) and the other is fat-loving (lipophilic). When added to the emulsion, the fat-loving ends bury themselves in the oil droplets with their water-loving ends sticking out. The result is a coating around the oil droplet that repels other oil droplets, keeping them from combining with each other.

Neato, yes? Common kitchen emulsifiers include egg yolks and soy (which contain lecithin), mustard (which contains emulsifying seed gums) and honey (which contains, er…I’m not sure). Commercial ingredients companies produce bewildering varieties of emulsifiers, usually mono-and di-glycerides which unlike tri-glycerides have water-loving regions on them. But there are all sorts of others.

Most people only think about emulsifiers in applications like salad dressings, mayonnaise and hollandaise. In fact emulsifiers are critical in the baking world as well. Egg yolk lecithin turns a chewy open crumb like this into a tender tight crumb like this. In other words, they’re essential for creating texture. But they also play a preservative role as well, as large blobs of oil or fat oxidize (spoil) more quickly than lots of tiny, well-dispersed ones. Oh yes, the benefits of emulsifiers are legion. Best not to get me started, I could go on about food additives all day, and I have work to do.

38 thoughts on “What is an Emulsifier?”

  1. Hello Mr. Joe,

    Thanks for the post. Please I just want to beseech you to try more and add on the additives. I have a whole lot of concerns about the use of them and emulsifiers.

    I use an emulsifier here in Nigeria called Excel Sponge. It is gel like in nature and it can only be dissolved in eggs. One day I tried whipping it up with part of the eggs I want to use for baking and it whipped up like meringue. Soft to hard peaks. I then incorporated it into the butter/sugar mixture and it went well. Too much of emulsifier destroys the strength of a cake, making it crumbly and too little, well just fine I guess.

    What are the differences between emulsifiers, cake improvers, and cake stabilizers? Can they all be used in the cake at once?

    Thank you.

    Wale

    1. I forgot to mention that emulsifiers can be great foam stabilizers too, as they reduce the surface tension on bubbles, making them less prone to popping. As for the other questions, let me see what I can do!

      – Joe

  2. hi Joe,
    i was wondering, would you happen to have any recipe for a crust free sponge cake? say like the chinese kind.
    thanks
    Maudlyn

    1. Hello Maudlyn!

      Do you mean something like a steamed spongecake? I confess I’ve never tried that. Sounds like a great future project though.

      Sorry I’m no help!

      – Joe

  3. If your batter “breaks”, does it actually make any difference to the final product? Wanted to do an experiment, but never got to.

  4. Would lecithin help a pretzel dough from tearing Joe? I’m having that problem since switching from Barley Malt Syrup to Spray-dried Malt Extract and I don’t understand why it’s happening. I replaced the Syrup with 80% dry extract and 20% water btw.

    1. Hi Jim!

      Sorry for the delay on your question. I’m guess that lecithin probably won’t be a big help since pretzel dough is so lean, but it might be worth a try. What about adding in a little honey to replace some of those sugars and add some stretch?

      – Joe

  5. Thanks Joe, I’ll try it. As you predicted, the lecithin didn’t help. With 59.5% hydration it’s odd to watch my pretzel ropes pull apart. I do add quite a bit of sugar and lard to my formula, but that didn’t seem to matter when I was using Barley Malt Syrup. Something about this dry Malt Extract…

    1. So wait, they’re pulling apart during the shaping or the baking step. And you’re adding granulated sugar? Maybe send me a picture.

      – Joe

  6. They are pulling apart as I am rolling out the ropes. And yes, granulated… should I be using powdered sugar. Is the granulated “cutting” the dough? Hadn’t thought about that…

    1. I think I’m starting to see the problem. My guess is that on the one hand the malt powder is absorbent, and when you add granulated sugar, which is hygroscopic, a lot of moisture is being taken up by those two ingredients. What if you used corn syrup or honey in place of the granulated sugar? My feeling is it’ll give the dough more elasticity.

      – Joe

  7. Joe, with your explanation in mind, I went back to making Syrup from Dry Malt Extract, (by boiling to near “thread stage” 2 parts water to 1 part Extract by weight) and, held back a little sugar. My dough is no longer breaking… yippee (and many thanks!)

    Now I just need to figure out the best way to bake-in or pre-top some Cinnamon/Sugar so I can heat-seal package them to sell.

    BTW, regarding emulsifiers, the powdered soy lecithin (.83%) made my pretzels noticeably softer (which is great in combo with VWG for chew).

    1. Very interesting all the way around, Jim!

      Regarding the pre-topping, I’ve been thinking about that. It’s a tricky one. I was thinking about pearl sugar the other day. That doesn’t melt easily and could be baked on with some egg wash. You might even be able to infuse that with vanilla bean pods or something like that. Too out there?

      – Joe

  8. Again, thanks. With a 58.34% hydration, 1.77% VWG, .59% Lecithin powder, and 4.73% each of Lard and Malt Syrup (plus more sugar) dough, nothings too “out there” for me Joe! Before your post, I concocted a butter/cinnamon-sugar/vanilla paste (applied at the tail end of the bake) which I’m pleased with. But, of course, I will try your suggestion as well. Fish well amigo…

    1. Thanks, Jim!

      So far so good. The weather is perfect and the fishing is very good. Caught some speckled trout today which were the food of the gods!

      Cheers,

      – Joe

  9. I tried your Pearl Sugar Pretzel idea today (I made the sugar) and sent you pics… it worked beautifully Joe. It’s a fun take-off on a salted pretzel and an inspired idea. I’ll stick to my paste though. But for the holidays, what could be better than a salted (looking) pretzel that’s really topped with little sugar bombs in disguise.

    1. Got them, Jim. They look great. Keep me up-to-date on your progress, please. I’ll be curious!

      – Joe

  10. Joe, so I’m now good-to-go with your inspired Pearl Sugar idea. Makes for a great two-for topping… a pretzel with candy on top! How cool is that? I’m having a girl (one to start) hit the streets with them in a basket — bagged in clear (un-sealed) plastic bags — and it will be fascinating to see whether a culturally unfamiliar food attracts buyers. But there’s one other issue I’m having… since these will be consumed at air-temperature… how might I help keep the crust crispy for more than a couple of hours? A crispy crust with a soft crumb is just about everyone’s goal for bread products, I know. But do you have any ideas on how to help these pretzels stay crusty? Btw, I am using the egg wash as a glue for the Pearl Sugar. And I don’t have a steam-injection oven… so it’s just a standard 10-minute bake at 250C.

    1. Hey Jim!

      That’s a toughie. That crust is of course why even roaming pretzel vendors have those little heater carts…to keep that crust. The only thing I can think of is a crunchy candy-like coating, but that’s going to make them pretty sweet. Any used Central Park-style pretzel carts knocking around down there? 😉

      But I’m most gratified that you’re testing the pearl sugar idea. I wish you all the luck in the world!

      – Joe

      1. Thanks Joe. My one day/night experiment in cold soft pretzel sales convinced me that it’s a bad idea. “Gotta be hot!” That’s my new motto. (And yet another potential teaser for your Cosmo remake… ). LOL. Love the Pearl Sugar though…

  11. Ooh…please continue. I am enjoying it. This is the best explanation, easy to understand piece of work. I found buttery cake that was very soft and didn’t seem to have pores on it. It’s densed, yet very soft. I wonder if emulsifier is responsible for this texture?

    Thanking you in advance.
    Rita

    1. Hi Rita!

      Indeed it does sound like the work of an emulsifier, what commercial bakers call a “high ratio” cake. There’s more on that here:

      http://joepastry.com/2013/on-high-ratio-cakes/

      You can find recipes for these types of layers in the left side menus under “Pastry Components” and then “Cake Layers”. There’s more information in the recipe posts as well. Let me know if you have any questions!

      Cheers,

      – Joe

    1. Hello Khazan. I’m not sure I understand. Do you want to know where to get emulsifiers?

      – Joe

  12. Hi Mr Joe,

    I have been trying to bake brownies that are crispy on the outside and soft and chewy (not gooey) on the inside – something like that of Mrs Brownie’s. I have tried many recipes but never quite got what I wanted it to be. I thought it was due to emulsifier but after reading, I realized that egg is an emulsifier. What could have gone wrong?

    1. Hi Kenneth!

      Describe to me a little more in detail what you’re after. When you say crispy on the outside, do you mean the top of the brownie? Or around the outside edge?

      – Joe

          1. Thanks, Joe. The brownies in the picture look gorgeous! Thanks for sharing so generously. I will certainly try it and will let you know how it went.

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