Many of us are now quite familiar with sous vide, and many have accepted it as a superior way to cook a steak when compared to the conventional method of cooking directly into the grill or skillet. It is indeed better. Though, what if we can make it even better? I wanted to test out a theory, which I just stumbled upon while doing an experiment that compares the differences between partial dehydration and freeze drying (this experiment should be done tomorrow). I was checking on the samples in the dehydrator when I noticed that the steak had developed a dry crust. I thought to myself “wouldn’t this brown better”? So I set out to test this thought.
I’ll share the results first, and delve on the details later below. In a nutshell, the dehydrated steak was much much better than the sous vide steak. The browning was absolutely even, and is a thicker layer. As a result, the steak had a beautiful thick, crisp crust. Also, with deeper browning there is more flavour. In the sous vide steak, the browning was really just on the surface. Also, in the sous vide steak, there are pockets of steam that formed under the steak, so some of the steak’s surface did not come in direct contact with the skillet.
Sous vide steak
Notice the various areas that are not browned, including the veined pattern.
Partially dehydrated steak
Almost no veined pattern, but the browning appears richer and deeper.
Now, this was something I knew should be considered between the 2 methods. Sous vide is hailed as the best way to keep meats juicy and tender due to the moist environment and the temperature control. Dehydration is obviously cooking in a dry environment, but the temperature is also well controlled. In fact, most dehydrators work between 55c – 60c. As expected, the sous vide steak held more moisture, but surprisingly, not by much. Weights were measured before and after dehydration and sous vide. The difference was only 2.5% with sous vide having 3.5% moisture loss, and 6% on the dehydrated steak.
So, here are my initial thoughts on why I got these results. But please keep in mind, these are my initial thoughts. I could be proven wrong. I welcome any discussion on the matters at hand.
First is the browning. The reason I think why partial dehydration results in better browning is that you are removing the moisture from the surface. Moisture prevents browning because water only goes up to a temperature of 100c, and you need a much higher temperature to start the maillard reaction (browning). Also, in the partially dehydrated steak, less steam is created between the steak and the pan, resulting in much more even browning, as well as more contact between surfaces. In the sous vide steak, surface moisture first had to be converted to steam before browning can occur. The production of steam results in another effect that hinders browning. Steam ends up being a layer that forms between the steak and the pan.
The second explanation I’d like to provide is with regards to the moisture loss. I spoke to my colleague about it and he gave me quite a simple explanation. He does have a masters degree in food science and is working on his PhD, so his explanation is quite likely, valid. He said that it was because of case hardening. When certain foods are being dehydrated, they form a hard outer layer, which acts as a barrier for moisture to escape. This may sound similar to the old myth that searing your steak locks in the juices, but it is different. Also, because the dehydration process is quite aggressive, you don’t have to leave it dehydrating for a long period. You only want to dry the surface.
It would be interesting to see what happens if you smoke a steak for 2 hours before cooking it. Configure the smoker to be dry, and at 60C.
Both steaks were not salted or marinated. Just bought from the store. I used common settings for the sous vide steak – 55C for 30 minutes. The partially dehydrated steak was dehydrated for 2 hours at 55C. Both steaks were finished on an iron skillet with approximately the same heat setting on a gas stove.
A closer look at both steaks.