Molecular gastronomy – oil and viscosity
It’s been awhile since I’ve posted material here on molecular gastronomy. I’m happy to announce that my absence was based on my recent trip to visit Molecular Chefs Jose Andres and Masterchef Ferran Adria!!!
I learned way too much and can’t wait to share with you ALL!
Another great piece of news I’ve got is my new molecular kitchen device.
Here is my new Toy: The Thermomix
Now to bore you with the MAD food science I learned while away. FYI, there are some great recipes past the science if you want to just scroll down. Enjoy!
Oil and viscosity
Molecular viscosity : v = l x c
elasticity: E = kBT/l³
When talking about the elasticity you got to imagine a spring. Imagine how the spring stretches and you will obverse its elastic constant. What makes foods soft, squishy or flow easily is critical to all aspects cooking. It is for this reason that we must examine the properties of elasticity and viscosity when dealing with food.
Here is an example of the elasticity of a raw thaw steak:
Elastic constant of a steak
E = F ⁄ A L ⁄ ΔL
E= 8,000 Pa
The amazing formula is as follows:
E =kT ⁄ l³
Elasticity / / (volume)
Before Cooking (RAW) 8×10³ Before 8.1 nm Before 8.1 nm
After Cooking (Cooked) 5×10⁴ After 4.4 nm After 6.8 nm
The stiffness of a material depends on the length between bonds .
Energy of bonds times their density
Stretching bonds to deform the solid
Units – Energy density
A material is a liquid if the molecules can move around each other
The fundamental quantity that governs this is the time that it takes for molecules to move around their neighbors.
If it takes a long time to move by each other, the material is very viscous.
If it takes a short time, the material is less viscous.
Example: Olive Oil
It takes longer for the molecules to move through olive oil than water because it has a higher viscosity.
length²/time v = l x c
where v = length
c = length ⁄ time
Very important Equations:
Molecular viscosity: v = l x c
elasticity: E = kBT ⁄ l³
Let’s look at the viscosity of hot oil
Hot oil flows faster than cold oil
Viscosity decreases with increasing temperature
Molecules move around each other more easily
Let’s look at how using a thickener helps make liquids thicker
Xanthan Gum makes liquids thicker
Xanthan Gum (E415): makes food thick and creamy; also stabilizes foods to help solids and liquids stay together
You could see Xanthan Gum is sauces, low fat or non-dairy, and dressings.
The reason thickeners works?
Thickener is a polymer
Polymer forms network in the water
This forms a solid gel
Note: The bonds in gels are not permanent
Molecules can move
Molecules must disentangle to move
This is important because it means if you form a gel you could easily manipulate it by shredding it in a thermomix or blender.
doing this will change the viscosity by either a small percentage or a large one.
Let’s get into some recipes with some molecular ingredients:
Soft Creamy Jelly
You will need:
100g of water, fruit juice, or wine.
100g of olive oil (extra virgin)
You will need to bring water to boil and stir in iota, whisking constantly. Take the saucepan out of the warmer and slowly add the olive oil, stirring constantly.
Pour mixture into molds and allow to cool.
Once it has set you could slowly remove the olive oil jelly from the mold
Finally, serve on bread with tomato and jamon iberico.
For the next recipe you will make Olive oil gummie bears
You will need:
150 g extra virgin olive oil
7.5g xanthan gum
7.5g locust bean gum
For the procedure you will need to use your thermomix at speed 3, veroma 100 C for 5min. Mix all ingredients.
Once the mixture is complete transfer to piping bag and pipe little goblets over cornstarch.
Completely cover with a thin layer of cornstarch.