We've had sous-vide salmon on the menu for quite some time, and I have a love/hate relationship with it. Part of that is due to the occasional guest's dislike of the unusual texture, and part of that is from my own dislike of certain aspects of it. The texture of a well cooked piece of sous-vide salmon is a beautiful thing. I am not a big fan of cooked salmon in general. Usually, it has to be raw or I won't eat it. Sous-vide is the bridge between the two. Succulent great flavor with an almost raw yet flaky texture. Over time, I have had to raise the cooking temperature of the water bath to deter guest complaints of this nature. I have even had an email discussion with Chris Windus at Bluezoo on the subject, and he has had a couple of similar complaints and solutions of low-cooked salmon.
Now, time has passed and our waitstaff is more adept at explaining the cooking technique to guests and reception of it has gotten much better. The moment is right to lower the temp again and tweak the technique a bit more. What needs to be tweaked... first of all, the white stuff that is exuded from the salmon as it cooks. It's horrible to look at, and it drives me crazy. Now, I have gotten rid of it. The answer is salt, and my first knowledge of it is from a 2005 article by Amanda Hesser (a really great read!). Bruno Goussault suggested to Michel Richard that by briefly brining the salmon fillet in a 10% salt solution, he could avoid the white stuff. Not being a scientist, I first had to find out what a 100% salt solution was, and then derive a 10% solution from it though simple math. Chris had mentioned in an email that a Canadian chef had once told him that brining would stop the albumem secretion also... even more reason to pursue this.
A 100% salt solution is water that is completely salt-saturated... meaning, it will hold no more salt. After making a gallon of this solution and measuring how much salt it took (I used tap water and kosher salt... this is a scienctific process, but I'm not making rocket fuel or splicing genes).
The first test was to make a 10% salt solution (1 cup of 100% mixed with 9 cups of tap). Actually, I figured my proportions by weight because I wanted half of the solution to be crushed ice. This is because the brine must be ice cold. I dropped one piece of salmon into the brine, and let it sit for 10 minutes.
In the 10% salt brine.
In the thermocirculator set for 61C.
Possibly, I was too eager in this first experiment because I kept the water bath at 61C (1 degree below the point when the salmon proteins completely denature) and I also added salt and pepper and olive oil to both the brined salmon and the control piece (about 40 minutes cooking to really give it a run). The test flopped as both pieces had exuded the white albumem that we are trying to get rid of. The reason for this could have been not enough salt, not enough time in the salt, too high a cooking temp, or the inclusion of sea salt, black pepper, and olive oil.
The next day test was with a 20% salt solution... same system of measuring out the proportions. I also allowed the salmon to sit in for 20 minutes to get a really good brine. Not being too scientific, but wanting quick results, I dropped the water bath temp to 50C (which is where supposedly both Keller and Richard cook theirs). This cooking time was also set for 40 minutes. Also, I added no extra salt or pepper or olive oil to the sous-vide bags this time (I'm horrible at the scientific process because of all of these deviations between the 2 experiments).
Back into the ice, 20% salt solution for 20 minutes.
But alas, results nonetheless. The un-brined piece was grossly discolored with albumem (even at 50C) and the brined piece was a beautiful color.
Even better, the brined salmon was salted perfectly with no added salt. This was also part of my plan. I ultimately hoped to come up with a technique that I could make a seasoned brine (with the whole spices that I am currently using to flavor the salmon, which is our Taiwan 7-Spice) and get full flavor infused into the fish just through the brine. Maybe a drop of sesame oil could be added to the bag.
The recipe for a half gallon of brine (without the added seasonings) is as follows (and this is an estimate on a 20% salt solution, not an exact scientific formula, and it is not in metric measurements, and unless I am grossly off I am aware of minor inaccuracies from the conversions)...
- 1 1/2 Cups kosher salt
- 1 quarts tap water
- 2 lbs. crushed ice
Heat the water and salt until the salt is dissolved (you should be able to do this with just warm water) then add in the ice and stir to get the brine to ice temperature. Brine the salmon in the solution for 20 minutes. Remove, then pat dry, then vacuum seal, then cook at 50C for up to 40 minutes. Chris said that he cooks his for 12 min at 50C. I think a reasonable compromise without affecting ticket times would be closer to 20 minutes... still succulent nonetheless.
And that concludes yet another discussion on how to have fun with things that suck.