In On the edge of pasteurization I wrote about including more food in my diet that people with compromised immune systems should avoid. I hoped that this diet would help give my immune system a much needed boost before heading over to Bangkok to sample the unmissable street eats like naem (แหนม), a raw pork dish. On hearing about my diet, a friend recommended that I experiment with sous-vide. A method of slowly cooking vacuum sealed foods in a precisely controlled water bath to maintain the integrity of ingredients. Nothing says E. coli more than undercooked and insipid chicken prepared at the hands of a sous-vide novice. Bring on Bangkok.
To cook sous-vide, or ‘under vacuum’, you need an immersion circulator, which is an expensive piece of lab equipment capable of maintaining extremely precise temperatures in liquid baths. I don’t have one, so decided to make my own with the help of a friend. By using parts sourced from China, we were able to convert a slow cooker into a water bath capable of maintaining temperatures within a fraction of a degree. To prevent the food from becoming waterlogged in this bath and spoiling, and to keep the juices and aroma that would otherwise be lost, you also need a vacuum sealer. I have been using a vacuum sealer for years. Removing the air from bags of food limits the growth of aerobic bacteria and fungi – keeping food fresher for longer. This is important for sous-vide, but removing the air also aids in maintaining an even cooking temperature as air is a very good insulator (it can also cause the bags to float).
Often, the first thing people cook sous-vide are eggs because they come prepackaged. As soft-boiled or raw eggs may carry salmonella bacteria, I thought I would try this too. I used the timings for cooking soft eggs found in Neil Perry’s Rockpool Bar and Grill. Because the proteins in the yolk and white coagulate at different temperatures, the process for cooking these eggs is in two parts. To set the yolk, the egg is cooked for two hours at 60°C in a water bath and cooled in a refrigerator overnight before being reheated to 60°C again. To set the white, the egg is cracked into barely simmering water and cooked for 45 seconds or so, after which it is removed and cleaned up of any excess albumen making for a neater cooked egg. These eggs are undoubtedly time consuming to make, and require thousands of dollars worth of kitchen equipment, but the result is not a duplicate of an egg that has been boiled, with the outside typically hotter than the inside. The result is an egg that is warm all the way through. Inspired.
What has been your most memorable sous-vide experience?
I’m now on Twitter and Facebook. Follow, like or subscribe to the sad pig for authentic food and stories of provenance. I’d also like to thank Gayle Laird from Exploratorium, for making his beautiful photo of the eggs at various stages of doneness available under a Creative Commons license.