Ask a Vegan Baker

What a quandary you have there Pammy!

Few things are more frustrating than having a staple food that you prepare often, get plagued by inconsistencies when you least expect it. It looks like you’re on the right track by taking advantage of xanthan gum; it’s great at stabilizing liquids by providing thickening and minor emulsification.

You’re doing the right thing by blending the soy milk, adding the xanthan gum and slowly drizzling the oil to the blender vortex until the liquids mix and thicken. It’s difficult to determine why your soy milk and canola oil came out of emulsification. Below I’ll go into a few strategies that may increase the reliability of your emulsions.

How emulsifiers work

But first let’s go on a brief overview on the science of emulsification: Most of us know that water and oil are immiscible, meaning, they repel each other. But why? Water molecules are polar, meaning they have two poles: a positive charge on one side of the molecule and a negative charge on the other side. Oil molecules are non-polar, meaning they have positive and negative charges dispersed throughout the molecule. These polar and non-polar molecules repel each other much in the way that two magnet ends of the same charge do.

In contrast to this repelling tendency, the water molecules and the oil molecules are super attracted to themselves. So much in fact, that they don’t want to have anything to do with their opposite. SO self absorbed- gross. This causes water and oil to each go into a shape where they have the smallest surface area between themselves, which results in them forming into large globs. Since oil is lighter than water, the oil glob floats to the surface, above the water glob. The repelling force that’s causing these two liquids to be immiscible is known as interfacial tension (this is similar to surface tension, but between two liquids instead of between a liquid and a gas).

If you can reduce this interfacial tension, you can convince these two liquids to not be so self absorbed and get out of the house and hang out (I mean c’mon guys). This is typically done by adding an emulsifier, a substance which works as a mediator between the two. I used to joke to myself that emulsifiers are the food equivalent of the great mediator Nelson Mandela (but then, I’m a huge dork). Emulsifying molecules have a polar side and a non-polar side. The polar side allows water to bond and the non-polar side allows the oil to bond. This reduces the interfacial tension enough to the point of where the water and oil consider hanging out, if only they could disperse a little more our of their globs.

Blending or whisking breaks the water and oil molecules up to the point of where they’re easily able to bond to the emulsifier and align into a contiguous liquid.

Common causes of emulsifier problems

Before an emulsion is started, the water and oil is whisked or blended so they’re dispersed into tiny droplets. After you add the emulsifier such as lecithin or xanthan gum, the emulsion starts. It first gets thicker because the water and oil molecules are packed together rather tight. As you add more of the water or oil, there’s more space between the droplets. As more and more of one liquid is added, the space between the droplets gets larger and larger until the point of where there’s a tipping point; it’s easier for the like liquids to bond back to themselves than it is for them to maintain the bond with the emulsifier. Your emulsion is now broken. Nelson Mandela was unable to make things work out despite his best efforts.

It’s possible that your emulsion is breaking because you’re pushing the limits of the emulsion. In this case, just a little too much of oil over water, or vice versa could be just enough to hit the breaking point. If you’re close to this emulsification limit, a minor variation in your method just might be enough to create inconsistencies between preparations. You might want to consider scaling back the oil slightly to see if it results in a higher emulsion success rate.

I highly recommend looking into different emulsifiers, particularly lecithin, which is a considerably more powerful emulsifier than xanthan gum. You can still use the xanthan gum for its thickening properties, but utilizing lecithin is breaking out the big guns in the emulsification war. Back in the day, there used to only be soy lecithin but due to the soy backlash, sunflower lecithin is now available. They should both work the same but I personally don’t believe that soy lecithin (and soy products for that matter) are as harmful as some people claim. So if you’re not a soy conspiracy theorist, save your money and just go for soy lecithin. If you are a soy conspiracy theorist, more power to you and sunflower lecithin shots for all!

Lecithin also comes in liquid form and granule form. I highly recommend the liquid form over the granule form, as the granule form tends to never really disintegrate into whatever I’m mixing. It almost seems like lecithin granules were created to be a cruel joke to whoever is unfortunate enough to stumble upon them.

I’d love to hear how you get this sorted out Pammy. Please let me know if you find a solution that works for you!

-Mattie