*I feel like writing in English today. If you prefer reading my blog in Indonesian, please bear with me this one time 🙂
So, this is IAP. And IAP is always a great time of the year, when I actually feel like at MIT, the place with endless knowledge and quirkiness waiting to be pursued. This year, besides taking several writing classes (2, actually: 1. Because I didn’t pass my Graduate Writing Exam 2. Because there is this cool class about graduate student blog which I am excited about, I also took “Learning Science through Cooking”.
Oh boy, that was an amazing class. I got to taste liquid nitrogen ice cream (again), (so much) chocolate -including chocolate caviar, and vauquelin.
Let’s start with something easy, shall we?
Vauquelin is quite easy, it’s basically a meringue but not quite the same. After you whisk a bowl of egg white (preferably copper bowl rather than stainless steel bowl), you can add a hint of lemon juice and a couple tablespoons of maple syrup, then microwave it for a couple of seconds.
The science behind turning egg white into foamy egg white that-doesn’t-fall-if-you-flip-the-bowl, is really interesting, though. Egg white is so rich of protein, but they are really ‘messy’. When we whisk it with whisker, we introduce air bubbles into the egg white, and allows the protein there to reorient themselves. The proteins which are hydrophobic will stick its tail to the air bubble, but the hydrophilic proteins will stick its tail to the ‘sea of egg white’. They build a ‘structure’ which is rigid enough not to let itself fall down when the bowl is flipped upside down.
Liquid nitrogen ice cream
This has always been a hook to incoming MIT students to comMIT and actually come to MIT. For me, somehow, I only eat this nitrogen ice cream during special times: 1. Orientation 2. Pretending to be a freshman during CPW 3. ESG graduation dinner (there was so much, I got 4-5 bowls of ice cream) 4. Last week, during this class.
Similar to the science of egg white, air bubbles are introduced to the ice cream batter by mixing and cooling it at the same time, to give that ‘creamy’ feeling, and no rigid ice structure was formed (like the popsicle, for instance). With ice cream maker, this process of stirring and cooling can take about 30 minutes.
However, it is much quicker using the liquid nitrogen.
Liquid nitrogen has a boiling point of -196 degrees Celsius. So, as soon as it gets out of dewar, it wants to evaporate, due to ‘really warm’ room temperature.
It instantly freezes the ice cream batter, but then it evaporates really quickly. It makes little ice crystals, but not enough to make it like popsicle. Then, we keep stirring it and pour some more liquid nitrogen, until it becomes creamy.
First thing’s first: don’t eat it when it’s still steaming cold. It can freeze your tongue, and you would not like that.
There is something amazing about chocolate. Not only the taste, but also the chemistry behind it.
Chocolate crystals are apparently like human. Depending on how much they are heated up (to what temperature) they will behave accordingly. It can become really soft (which you don’t want, because melted chocolate is just so icky), but it can become hard but smooth (and melt only when it’s inside your mouth @ ~35-37 degrees C).
Tempering is the way to go. Once you get a batch of liquid chocolate (which will soon be cooled and become your chocolate bars), you need to give them ‘good chocolate’, the one that is hard but smooth. This will provide as a ‘template’ for the chocolate crystal in the sea of chocolate to act the same way.
Apparently, if you don’t do tempering, you get that really-soft-chocolate, which is icky (and worth less, thus unprofitable).
It’s the same as human, right? We act based on our ‘template’, which can come from our environments, people around us. Without realizing it, we act the same way as them. So, it’s important to first and foremost: check on your environments, and what kind of people you are friends with.
Enough with the cliché, haha. So, we also got to try a lot of chocolate samples while in Taza, and look at the production process. Taza is the vegan, direct trade, organic, non-GMO, gluten-free chocolate company based in Somerville, which is just outside Boston and Cambridge area.
Last but not least, we also made chocolate caviar from hot chocolate. This process in molecular gastronomy is called spherification. We can mix any liquid (in this case, hot chocolate), with sodium alginate, and drops it into a cold solution full of calcium chloride. Just like how air is mixed with oil, a spherical ball is formed almost instantaneously. However, you need to wait long enough until a nice layer of ‘jelly’ is formed in outer part, but it is still liquid inside. So, when you chew it, it still bursts and gives you that ‘caviar sensation’.
How long do you need to wait? According to what our instructor, Dario Marrocchelli said:
You can drop the liquid (hot chocolate) using syringe (costs about $12), or ‘rapid caviar maker’ (costs about $70).
Sorry for the blurry images. I was too excited when I took the class 🙂
So, I hope I gave you a nice introduction in how science is behind our kitchen as well. I would like to suggest you reading The Food Lab by J. Kenji Lopez-Alt (which the picture I showed on this blog several months ago). My instructor, Dario, also suggested another book: On Food and Cooking: the Science and Lore of the Kitchen by Harold McGee.