If you follow this blog, you’ve probably already seen the pictures and videos: At the restaurant Alinea in Chicago, Chef Grant Achatz and his team serve a unique dessert: a chef unrolls a silicone mat on the diner’s table and then serves various sauces and components right on the mat, no plate required.
The spectacular design and plating of the dessert make it unique. How do they do it?
I first learned about this during Chef Achatz’ presentation at the Harvard Science and Cooking course: he mentions the dessert in this video at the 46 minute mark .
Look closely at the above picture. You’ll notice that the orange sauce forms squares, while the red and white sauces form rounded shapes. The two sauces are simply poured from the spoon onto the mat, so how come they end up in different shapes? Based on Chef Achatz’s explanation, it had something to do with a grid pattern in the mat, so I decided to investigate further.
The team at Alinea was kind enough to give me a sample of the mat after their talk. I looked at it under a microscope, as shown above (the ruler has 1-mm markings).
I tried re-creating the Alinea recipes in my lab. Most liquids, including ethanol and glycerol, actually formed squares, not circles! It turns out the edges of the liquid tend to run along the grid lines of the mat, which minimizes the surface area of the drop. The mystery then became how the Alinea chefs create their circles.
At Alinea, the honey-milk sauce that formed circles was actually a gel that had been set into a solid and then blended to form a viscous liquid. With some experimentation, I was able to create the same effect using a simple agar gel.*
In the above photo, you can see drops of the blended gels with different agar concentrations. The first row is 0.6% by weight, the second row is 0.3%, and the third row is pure water. Notice how the pure water samples form squares on Alinea’s special mat. A second set of drops replicates the experiment in the background.
The elasticity of the fluid gels seemed to be the key factor for maintaining a round shape. Based on this preliminary research, it seems that the spreading behavior of the sauces could be replicated by using different combinations of hydrocolloids with any sauce – not just chocolate or honey. Meaning, you can get different shapes on the mat just by changing the concentration of the gel! This experience left me with an even deeper admiration for the chefs at Alinea and their openness to serendipity.
If you have done any similar experiments, please let us know in the comments.
* Agar is basically vegetarian gelatin. It’s made from algae, and is used in everything from ice cream to microbiology. Check out our ingredients guide for more information.