SousVide Supreme Demi: Initial Thoughts On Stability

When I first started cooking sous-vide, the holy grail was temperature accuracy and stability.  I think this is very important for certain applications such as eggs, and for professionals and sous vide geeks.  However, if you are a general home user, I don't think accuracy and stability to within 1º is of the utmost importance.  

That being said, I know this is important for most of the regular readers of this blog.  Unfortunately, I have a job and I don't own a high quality data logger (*), so I am not able to give you a super accurate reading on the temperature of the water bath.  I will tell you that I recently ran a 136ºF short rib from one to three days inside of the SousVide Supreme Demi.  I checked in to see what the readings of the SVS Demi's PID controller, and would see it vary from 135F - 137F.  I confirmed some of these readings with digital thermometer that was rated with +/- 1ºF accuracy.

That being said, I want to rerun some tests to see if I can get different results.  For example, I ran the device with the water being filled up to the fill line and not to the max line.  With more water in the device, I might have seen more stability.

Now, let's talk about my favorite cut of beef to prepare sous vide: the short rib.  The reason this is my favorite is that you can prepare a short rib medium rare, and have it be the most unctuous and tender short rib you have ever eaten.  This is because you can break down collagen at 136ºF and not over cook the meat, and while fats break down, they don't render out.

Since I wanted to test long term stability, I figured I would run another test I have been wanting to do for a long time.  One short rib, same temperature, three time periods.  How does this all work?  Easy:

1. Set SousVide Supreme Demi's temperature to 136F.  Will convert collagen to gelatin slowly, keeping meat medium rare.
2. Drop three slices of the same short rib at 24 hour time intervals.  Each short rib had zero additions (no fat, no salt).
3. Remove bags at same time.  Now I have  24 hour, 48 hour and 72 hour samples.

Sous Vide Short Rib Exteriors

The exteriors of all three pieces are vastly different in color.  This doesn't typically matter much, as you will usually post cook sear the meat anyways.  I was a little surprised by the fact that the 48 and 72 had such a different color.  The 24 remained basically pink while the 72 is almost lacquered.

Sous Vide Short Rib Interiors

The interiors looked a lot more similar.  The 72H looks a little darker because of inadequate lighting.  I was secretly hoping that I would see more detail in the differences between the 48 and the 72.  There is such a difference between them when you eat them that it is a little disappointing to see that there is no visible magic.  It's like cutting up the goose that laid the golden egg and instead of finding golden eggs just seeing guts.

(*) Does anyone have any recommendations on a good temperature data logger?  Ideally, I would like something like the Voltcraft K202, but it isn't available here in the US.