Sous Vide: Day One

April 11th, 2011

As many have noticed, I’m a bit of a gadget hound.

Today’s new entry – a Sous Vide setup. I’d been wanting to try Sous Vide (french for ‘Under Vacuum’) for a while, but the multi-thousand dollar costs of the setups put me off.

Then I found Sous Vide at Home. It’s a simple box that you plug in to a rice cooker, and it uses a combination of a temperature sensor and turning the rice cooker on and off to maintain a constant temperature in the water bath. Together with a vacuum sealer to seal the meat in the total cost was less than $300.

Today’s first experiment was a simple one – a soft boiled egg.

Let’s take a brief excursion into the science of cooking first.

Cooking is not mainly about heating things up. It’s about chemical reactions. The two biggies in this case are protein denaturation and the malliard reaction.

The malliard reaction is what happens when food browns as you grill or bake it. It’s really important for a lot of flavours. And it happens at around 154 degrees C, which is why grills and ovens need to be at least this temperature when cooking meat. But we can add this later (e.g., with a blowtorch). We’ll be coming back to this one tomorrow.

Protein denaturation, on the other hand, happens at much lower temperatures. Denaturation is when proteins lose some of their structure due to external stress, in this case heat.

The clever bit comes in the fact that different proteins in food denature at different temperatures, and so by careful temperature control we can create tastes that are otherwise practically impossible.

So let’s come back to eggs.

Eggs are composed of lots of different proteins. So for every temperature form around 57 degrees C (which is effectively uncooked) through to 90 degrees C (Egg yolk becomes crumbly) we get a slightly different result. The most interesting results are in the range from 62 to 70 degrees.

So to start: one egg, in shell, cooked at 65 degrees for one hour. Another point to note about Sous Vide is that it’s kinda slow: but the good news is that you don’t need to hang around while it cooks. For many things, such as meat, it doesn’t matter if you leave it in for several extra hours. Eggs are a bit twitchier though.

The result: A runny, slightly set egg white, and a firm but gel-like yolk. A cross between a hard boiled and soft boiled egg really. And with a really interesting taste.

Anyway, day two will see some pictures of the whole setup, plus my first attempt at cooking some meat.