My immersion circulator is working again! And the first thing I decided to do was to cook eggs at 63.0 °C for 40, 60, 75, 110 and 155 min and show you the results. If you read my last blog post on Perfect egg yolks or have stumbled across the paper Culinary Biophysics: on the Nature of the 6X°C Egg you may recognize that these times correspond to egg yolks with textures similar to sweetened condensed milk, mayonnaise, honey, cookie icing and Marmite respectively. I used the iso-viscosity graph from the paper mentioned to determine the cooking times as shown below.

The figure shows how cooking times at 63.0 °C are determined to achieve different textures. (The figure is used with kind permission from Springer Science+Business Media: César Vega and Ruben Mercadé-Prieto in Food Biophysics 2011, 6:152-159, Culinary Biophysics: on the Nature of the 6X °C Egg, figure 8, page 158. The legend overlay has been added by me for clarity.)

As the individual eggs reached their cooking times they were held in cold water until the last egg was finished. I then cracked all the eggs and took the pictures below to illustrate the differences in textures. I think the picture speaks for itself. The amazing thing is that the only difference between the eggs is the cooking time!

It can be difficult to judge textures properly from still photos, so I also shot a few video clips to illustrate the texture of the 40, 75 and 155 min eggs (by the time I shot the videos the yolks had become more viscous, possibly due to cooling and/or evaporation). The texture ofthe 155 min egg yolk was perhaps the most fascinating with a tremendous plasticity. There must be some exciting culinary uses for this!

If an egg is to be served by itself one will typically also want to set the white. There was a question about this to my previous post, and a reader even tried with 2 min pre- or post-boil. Without cooling the difference between pre- and post-boil was quite significant as evidenced from the pictures. I did a similar experiment but cooked the eggs at 63.0 °C and opted for a 3 min pre- or post-boil with the small difference that I cooled the egg back to room temperature after/prior to the pre-/post-boil to avoid any interference between the 63 °C and 100 °C treatments. This worked very well and I wasn’t able to detect any difference between the pre- and post-boiled eggs.

It doesn’t matter if you pre- or post-boil your egg as long as you cool it to room temperature inbetween the boiling water and the temperature controlled water bath.

Food Geeks: Liking to eat is one thing, but becoming really familiar with the exact time and water temperature to cook the perfect soft-boiled egg? … This elevates hunger to a seriously geeky level…

I kind of feel a finger pointing at me But believe it or not, there were more than 30.000 who visited the page Towards the perfect soft boiled egg last year (and it was first published in April), so my dear fellow food geek reading this: You are not alone!