Problems with steaming soy milk and pouring latte art

I can make a nice microfoam with both brands of soy milk I use (Earth Balance unsweetened and Organic Valley unsweetened) but when I pour to make latte art, it is too thick and floats, creating poorly defined shapes at best.

I heard about a Pacific brand soy milk made specifically for making lattes called Barista Series, Soy Blenders. I looked it up on and start reading people’s comments. People seemed to really like it and pointed out that it was able to withstand higher temperatures than other soy milk. I found the information and photo below on the pacific foods web site and they too claim that it can withstand high temperatures.

 Pacific Barista Series™ Original Soy Beverage (Formerly Plain Soy Blenders)

Pacific Barista Series™ Original Soy Beverage (Formerly Plain Soy Blenders)

Specially formulated to withstand high temperatures and deliver consistently smooth, velvety microfoam. It performs as well as (or even better than) dairy – perfect for latte art.

  • Organic soymilk (filtered water, whole organic soybeans)
  • Natural cane sweetener
  • Dipotassium phosphate
  • Expeller-pressed canola oil
  • Sodium citrate
  • Natural Flavor
  • Sea salt
  • Carrageenan

I did further research on the subject of soy milk curdling at high temperatures. There was a a difference of opinion on the cause. Some said that it was due to excessive heat while others claimed that it was caused by acidity. I researched further and found this study that showed that it was acid alone that caused curdling un-influenced by heat!

On Barista I found this useful comment by Jacoby Steele. Soy doesn’t have the same consistency as milk, or the nutritional make up- so it really shouldn’t be treated exactly like cow’s milk…  I’ve had success with keeping the tip of the wand to a 45* angle like you’d do for a capp, and barely submerge the tip.  You want to have constant texturing until about 100* and then barely submerge it to keep everything moving.  Soy foam has a bad habit of separating quickly if you don’t let it mix (or swirl) under the wand as long as possible. and don’t steam it over 130*. I’m lactose intolerant and i can pour decent latte art with the technique i just described without curdling.
Here is another comment on the same page that might be helpful. Reply by Chris Holden on April 18, 2012 at 9:35am So if anyone is interested in the science, by adding soymilk to hot coffee you are basically following the recipe for making tofu! Heat + coagulant + soymilk = tofu, though usually a salt such as magnesium chloride (nigari) is used as a coagulant rather than an acid. Lemon juice can actually be used and although coffee is not sufficiently acidic to make usable tofu, it will make a mess of your drink. Typically temperatures of around 170F+ are used for tofu production, though again, anything over 120F coupled with an acid could be enough to spoil your drink. Some soy creamers may contain a stabilizer to prevent this and the variations people experience are usually down to additives of some kind in their soymilk, though I can’t recommend one in particular. Otherwise you are fighting the laws of chemistry I’m afraid! (I do actually make my own tofu regularly for Japanese cuisine and find the art & science of it almost as interesting as that of coffee!)