I've had a couple of Kelcogel's gellan blends for quite some time, and just like so many other things faced with limited amounts of time they were forgotten and buried. After reading (or viewing) Chef Sean Brock's photo of onion puree made with gellan I felt it was time to go deep into the vaults and retrieve our little LeSanctuaire bags of the Kelcogel product... specifically gellan f.
After searching the internet and finding a few more applications that went under the radar before, it was time to play with even more textures that were possible with Gellan F. Chef Brock apparently set the onion puree with gellan f, then pureed it. After reading the patent's description, it seemed it was possible to get various textures using the gellan through the use of mechanical means as well. This is due to gellan f's submission to shear force... in other words, even very brittle gels made from gellan f have palatable textures because they tend to 'liquefy' when chewed (or when force from the mouth is applied). Different textures were derived depending if liquids were allowed to set unagitated or if shear was applied during the set period. Guidelines were also stated for temperatures... blend in cold, activate at 212F (boiling), gel set beginning at 70F (room temp) down to 40F (refrigeration).
I made one gel using the left-over roasted ginger apple puree (which was a fairly thin liquid like apple juice after being strained) with 5% gellan f added. This beginning percentage was derived from the examples on the freepatents website.
Just from my experiences, this looks like a lot of powder compared to base liquid. I went ahead anyway and did 2 samples at this ratio. One was left to set still at room temperature, and the other was agitated during the set period. Lacking any better equipment to perform this task, we left it in the Vita Mix at slow speed.
Nice vortex. This, however, did not really work since the friction of the blender never allowed the gellan to reach the gel state. When the mix was spooned out or stopped, the texture was of clumped up hard brittle gel, and not the 'mousse' type texture the procedural notes stated it would be. To understand the way gellan f begins to set, think of the gellan added product as a liquid alginated substance and the cooler air around it as a huge bath of calcium chloride solution. It will gel from the outside and work its way internally. When attempting to blend this 5% sample in a blender after being fully set, I ended up with a useless thick paste... experiment failed. I really can't imagine any use for the gels set with such a high percentage being of any culinary use. One of the keys to hydrocolloids is to use as little as possible to achieve the desired texture. So considering that, we went with a significantly lower amount.
I used the notes from one of the other applications on the patent site, which was 1% gellan f. This was supposed to yield a set gel that turned to liquid when force was applied (as in sucking through a straw, chewing). The way that gellan reacts to applied force is what makes it interesting for achieving different textures (even moreso than agar agar being manipulated during the set period).
Here is a gel at 1% (minus the bite I took out of it). It is completely set. When scooped out and blended, the texture is a smooth 'slightly' fluid gel... like pie filling.
Smooth texture, great mouthfeel (even at 1%), no off flavors added, and the heat-resistant benefit of gellan f. Notice it remains unchanged after being directly blowtorched for 45 seconds straight from 2 inches away. Just warm applesauce now with a slight amount of melting.
Sean Brock stated .45 percent for food purees which are obviously thicker from the beginning. This 1% was used for a more liquid gel although that amount can probably be lowered a bit.
I tried one more sample using a flavored tomato liquid. We plan on having a warm tomato jelly going with pork belly for an upcoming Rising Star Chefs even in Mar Lago this March. The following recipe was used and the percentage is again lowered (this time to .7%).
735g oven roasted roma tomatoes (sharked and halved), 18g clear agave nectar, 5g fresh basil, 1.5g crushed black pepper, 2g sea salt. Puree and strain the mixture and add .7% gellan f (for my recipe, 492g tomato liquid with 3.4g gellan f). Shear the gellan in completely with a hand blender, bring it to a boil for 1 minute, pour and allow to set.
The gel will set while still very warm. At this point, puree the gel in a blender.
With .7% a fairly stiff fluid gel is achieved. It may be possible to go down to .5%, but although the set seems very hard and brittle, the resulting purees are a broken down fraction of that. The gellan textures are much more affected by mechanical means than by temperature. Once the blend is made, the soft gel can be refrigerated and does not 're-set.' It will remain at the texture above (and this is a warm gel during the time of the photograph).
I have to favor Chef Brock's method for this technique (setting then blending). It seems unnecessary to rely on shearing before the set point (unless you have some seriously specialized lab equipment other than a VitaPrep). The manipulation of texture with gellan f reminds me of agar agar due to the variety of texture that can be achieved.
Now I'm so gellan, I'm like Magellan.
