Thursday, March 8, 2012

Trying out some new salt ideas

The salt conversation with Tony Maws has inspired me to do some salting "lab" work.  Here are my findings and thoughts:

French Gray Sea Salt vs Diamond Crystal Kosher 
I've been living very happily with Diamond Crystal Kosher salt.  But Tony assured me that there is a huge difference between salts and that fine grain French gray sea salt (called sel gris in French) is one of his favorites for basic seasoning of proteins.  

Try number 1: 365 fine grain sea salt
I set out to find gray sea salt.  When I surveyed the salt selection at my local Whole Foods, I found all different colors, but no gray.  Given the options, I thought I'll give 365 brand of fine sea salt a shot. When I opened the container, I found the crystal shape and size awfully similar to table salt.  They were so fine that the salt was difficult to pinch with fingers.  When you use salt with a salt shaker, it's hard to tell how much you are using.  That's why I prefer to pinch it with hands.  It was also very hard to distribute this salt over a piece of protein without over-salting some parts.  This can becomes easier to understand when you look at the weight of these salt.  

1/4 tsp of table salt = 1.5g
1/4 tsp of fine grain sea salt (365 brand) = 1.2g
1/4 tsp Diamond Crystal kosher salt = 0.7g

The weight is what determines the amount of sodium chloride (and thus salinity).  Since I need much more Diamond Crystal kosher salt by volume to get the same level of salinity, I have a bigger margin of error.  It makes it easier to distribute the salt evenly over a protein since a few crystals don't make or break it nearly as much.  

Try number 2: Fine grain gray sea salt from France
I finally found fine grain French gray sea salt on Amazon and 2 days later it was at my door.  The texture was way better.  The crystals were smaller than Diamond Crystal Kosher, but bigger than table salt, and were easy to pinch.  Unfortunately, there was no nutritional info on the package, so I had to weigh it to find out how it compares to other salts.  

1/4 tsp of fine gray sea salt = 1.1g

Since my scale confirmed the official measurements of other salts pretty well, I decided to trust it on the gray sea salt weight.  Now it was time to put it to use.  

I seasoned one trout fillet with Diamond Crystal Kosher salt and one with gray sea salt.  I weighed both the fish and the salt to make sure they had exactly the same salinity.  I pan seared both fillets in grapeseed oil, but added no other ingredients.  Jason and I had them side by side.  The verdict?  We couldn't tell the difference.  Tony talked about the beautiful mineral flavor of this salt.  When I put my nose a couple of inches from a bowl of salt, I did detect an iodine smell (I guess what people refer to as mineral or metallic smell).  Can't say I loved it, but it's a personal preference.  I didn't detect any smell from Diamond Crystal Kosher.  But that's when I was smelling a whole cup of salt.  Once it was on the fish, the two salts seemed identical.  Of course, people's pallets are very different and quite possibly others can tell the difference.  Though according to this article by Harold McGee, it's questionable how much difference most people can tell.

A few days later, I encountered another issue with gray sea salt.  As it sits in an uncovered bowl, it gets a bit clumpy (kind of wet looking).  This makes is more difficult to distribute evenly over proteins.  

% of salt by weight
For about a week, I've been weighing my salt when seasoning fish (I'll try to weigh it for meats too, but we've mostly had fish last week).  Why was I being so anal?  I feel that I am not always consistent when seasoning.  Craigie line cooks are lucky.  They have Tony standing next to them and evaluating their seasoning.  Since that's not an option in my own kitchen, I figured some quantitative information could help.  Tony said that we start to perceive salinity when it's 0.7% by weight.  When he cooks, he aims for 0.7% - 1% by weight depending on the recipe.*  After a few experiments, I settled on 0.7-0.75% of salt by weight for fish.  Not sure what it is for meat yet, but my intuition is that it's a bit higher for medium-rare meat and maybe a bit lower for braises and stews (because you lose way more water during braising).

You don't need a super expensive scale to try this experiment at home.  You just need 2 cheap scales:

Basic kitchen scale that sells for about $25.  You'll use it to weigh your proteins.

Tea scale that sells for about $15.  You'll use it to weigh your salt.  It is extremely accurate (1/100 g increments), but can only handle tiny quantities.  




When to salt and how?
In this experiment, I tried salting fish with 3 different methods: salt right before cooking, salt 2 hours before cooking, and brine. For brining, I tried 5% solution for 10 minutes, 5% solution for 30 minutes, and 6% solution for 1 hour.  It's hard to tell if comparing brined protein with presalted protein is like comparing apples and oranges.  Without sending my fish to the lab, there was no way for me to tell the exact salinity level of it after brining.  I went with how it tasted to me and Jason.  10 minutes in the brine seemed to be too bland.  30 minutes tasted about the same as a protein salted with 0.7% of salt by weight, 1 hour in 6% solution tasted about the same as 0.8% of salt by weight.  I did these experiments with swordfish, since it's one of the fish that could benefit from brining according to Tony.   

There seemed to be no difference in juiciness of the fish.  I weighed the pieces before and after cooking and they all lost roughly the same percent of water during cooking and tasted equally juicy.  The conventional wisdom is that the brine makes the protein absorb water.  From my experiments, it took an hour in a 6% solution to make swordfish gain 1.5% of its weight.  Considering the fact that some of this extra weight was salt (about 0.8%), it really doesn't leave much for extra water.    

Although juiciness didn't vary between the pieces, the flavor did.  The brined and presalted fish was more balanced.  There was no distracting salty outside that we got in the pieces that were salted right before cooking.  The brined and presalted fish seemed more flavorful, but less salty.  But we couldn't tell the difference between brined and presalted.  

I am not discounting brining for pork, poultry, etc.  It might indeed help a protein hold on to its moisture (or compensate by making it absorb additional moisture) when it's cooked to high temperatures.  But the highest I cook any fish is 135 (I take it off the heat even earlier), so a brine is not necessary.  

One more pinch
Generally, everyone in my family prefers proteins seasoned in advance.  But I found an interesting pattern.  We rarely reach for a bowl of salt while eating fish, but frequently want another sprinkle on our meats and chicken that were salted a day ahead unless I am serving them with sauce.  There is something desirable about not just flavorful, but noticeably salty chicken skin or roast crust.

* since all proteins lose weight when they are cooked, the final percentage of salt to weight is higher.  

4 comments:

Teri said...

Interesting. I have several types of salt that I am going to do taste tests on. If nothing else... I'll have fun! Have you read "Salt: A World History" by Mark Kurlansky? Fascinating, as is his book "Cod".

Helen said...

Hi Teri,

I haven't read Kurlansky's book yet. Everyone always mentions it when the salt conversion comes up. From the description and reviews of it on amazon, it sounds like it's mostly the history of salt. What I want is the some studies on the taste perception of salt. I guess that falls into the realm of psychology and physiology. Does he cover any of that in the book? If so, I'll try to get it.

Cheers,
-Helen

Anonymous said...

There is a way to get a known concentration of salt, at least in small pieces of meat or fish. This idea is from Modernist Cooking. Take your item and water, weigh them together, then put enough salt in the brine to bring to concentration in the total weight to your desired goal (say 0.5%). After enough time has passed the solution is at equilibrium so the salt concentration in the item must be at the desired value. The beauty of this approach is you can't over-brine, the way you can with a 6% brine solution; no matter how long the item is left in the brine the concentration inside it cannot exceed your desired value, no lab test required. The problem can happen on the other side, under-brining, if the piece is not left in long enough. For smaller items he suggests a day or two is long enough, but for large items like an entire bird he says it might actually be weeks for the diffusion to finish.

As far as lab testing, you can approximate it at home with a salinity meter such as those used for aquariums (around $100 or so). If you know the weights of the item and water, you can dump in a weight of salt and then calculate what the water salinity must be when the desired weight of salt has entered the meat.

Helen said...

Anonymous,

So much good info! Thank you. Had no idea salinity meters are so affordable. Myhrvold's idea of a long soak in a weak salt solution is intriguing. I wonder what are some side effects of that. Does the poultry skin brown as nicely? Does the protein lose any flavor? Is it safe to keep a whole chicken in the solution for weeks? Also, not sure how practical all this is. My problem is not that I can't season perfectly, but that I can't season perfectly AND conveniently :) Though it seems to be way less of a problem at home than in restaurants. I find restaurant seasoning all over the place. I wish I could order some percentage of salt the way I order doneness. For example, I'd like that steak medium-rare with 0.8% salt by weight.

Cheers,
-Helen