Chocolate – How to add salt and get it to permeate throughout chocolate

Speaking as pure theorist here, because I've never compared the saltiness of cooked chicken.

I think that there are two things you will have to think about. The first one is osmosis (water that gets soaked into the meat through cellular membranes), the second one is transport through porous media - like a sponge, the open ends of muscle fibres of your chicken soak up the liquid you put them in. What you want to do is to prevent osmosis into the chicken (because only pure water will go in through osmosis, concentrating the salt outside) and maximize absorption. I will assume that 0.9% saline is isotonic for a chicken, and I think this is a safe assumption, because veterinary saline isn't marked as species-specific. Seeing that your soup liquid is 0.27% saline, you can expect some osmosis to happen. *

Let's tackle the more interesting part first. You want more absorption to happen. The absorption is described by the Washburn formula, and you want to maximize your L.

• L improves with time. Luckily, a soup is meant to be cooked for a long time anyway. But when you wonder whether to give it some more time on the stove or not, more time is probably better. Keep the temperature lowish for less evaporation, and a lid on which will drip back evaporated water.

• L improves with lesser viscosity. No way to influence it in your basic recipe, but in a real soup, avoid thickening. So don't use starchy ingredients, or at least, wash them before adding.

• Surface tension should be kept high. Again, this is ingredient-specific. No way to influence it in the basic recipe, but it could turn out that some vegetables are reducing your surface tension a lot - I can't think of a soup vegetable or a herb or spice which is famous for a high saponine content, but it could happen. Also, you should give your pots a finishing wash with clean water if possible - detergent and dishwasher finishing liquid reduce surface tension a lot.

• Pore size. My intuition says that this should have the biggest effect in the soup case, as you probably can't influence viscosity and surface tension too much. Obviously, the bigger your holes, the more water comes through. A good way to do that is to thoroughly denature your proteins. The first and most common way for that is prolonged cooking time. Second, brining in concentrated saline (6%) and/or acid before you cook will attack the meat surface, again denaturing proteins. However, I don't know how wise it is to use this option, because some of the brine will get absorbed into the chicken, which will leave less space for broth and will increase salt content as a whole. (This assumes that you salt the broth; Brian's idea of not adding salt to the cooking water after brining has merit). Third, you can use meat from the freezer (this is a very likely reason for the mixed results you saw until now). Freezing produces ice crystals, which rupture cell walls. When you use the thawed meat in a soup, there are more holes for water to flow in.

• The Washburn formula is for a single capillary. But the more capillaries you have, the more absorption you get. So, what you want to do is to cut the chicken meat perpendicularly to the muscle fibres. And cut it into many small pieces instead of a few big ones.

Now we took care of the absorption, let's look into the osmosis. You can't change the salt content of the chicken's cytoplasm. But for osmosis, you have to separate the two solutions by a semipermeable membrane (the cell wall). Poke a hole in the wall, and the osmotic gradient vanishes when the liquids mix. So everything from the third point on absorption helps you reduce osmosis too.

As for your suggestions: 1. I see no reason why slow or quick heating will change absorption. I guess the products of a Maillard reaction could clog some pores, if you sear before cooking, but it won't happen during boiling. As I said, cook slow because of evaporation. 2. The chicken shouldn't absorb salt, but salty water, see the footnote. Although, if there is a hole in my theory, this is a likely place for it. 3. I doubt it, but if you wash it, you could free eventual clogged openings. 4. Certainly, cook longer.

To summarize: Cook meat which has been frozen, cut in small pieces perpendicularly to the grain, and stew it for a long time.

* I don't see a mechanism for the chicken absorbing a higher percentage of salt than what you have in the broth. I assume that in your "normal" cases, you are left with salt content near the initial 0.27%, and in bad cases, this gets concentrated.

Update As requested in the comments, I am providing an explanation about "cutting across the fibers". Short story, meat is made up of muscles, and a muscle is made up of fibers, or bundles of bundles of cells. You can easily see them in raw meat. You want to slice across them, so their ends are open, as opposed to along.

The good, long explanation with pictures can be found on Serious Eats

I think your best bet is to change your recipe. While trying to figure out the exact process that sometimes makes your soup work does indeed sound like an interesting science project, it doesn't sound like its going to yield a reliable recipe. Especially since you've got to deal with supermarket chicken from suppliers that may change their processing procedures whenever it suites them—maybe even from package to package, depending on which plant it came from, or the specifics of the chickens the plant processed that day.

There are easy, reliable ways to get salt into chicken. The following two will get you salty chicken, every time you do it:

• Put your chicken (chopped up or whole) in the fridge submerged in a 13% brine for a day, and you'd at that point have chicken which would be (once cooked) inedibly salty (among other problems).
• You could chop your chicken fairly thin, and pack it (again in the fridge) in kosher salt. Then it'd become dry, and also very salty.

Of course, that'll be far more salty than you want. So you'll want to scale back—use a 5–6% brine, put it in only for a few hours, etc. But that will get flavorful chicken every time.

Then, to keep your soup base from being salty:

• rinse the brined or salted chicken before adding to the soup (to remove any salt resting on the surface)
• keep salting of the soup to a minimum.
• don't overcook the chicken, that'll force more liquid from it.
• make sure to use low-sodium chicken broth. Normal store-bought broth/stock is pretty salty.
• if too much salt leaches from the chicken, cook the chicken separately and drain it.

</rant>

edit: random suggestions since the above apparently doesn't work

• Commercially, many things are quick-frozen (e.g., fish) to prevent ice crystal damage. It would seem to follow then, that since you're trying to cause ice crystal damage, you want to freeze as slowly as possible. Easy way to do this would be (assuming your chicken is already under 40°F e.g., in the fridge) to insulate it before throwing it in the freezer. So, put it in a freezer bag, but then wrap the freezer bag in some kitchen towels, then toss that in the freezer.
• In previously-frozen (commercially) chicken, there may be some anti-ice-crystal additives, I have no idea. Previously-frozen isn't always sold frozen. Check the package, it should say (probably in tiny print).
• You could try a second thaw/freeze cycle (just make sure to thaw in the fridge, or in cold water, not the microwave, for food safety reasons—keep it under 40°F). This will certainly increase the effects of freezing (and would normally be avoided for flavor and texture reasons)
• This isn't freezing, but may accomplish the same goal: you could try one of the 40+-blade meat tenderizers.

Also, as a final note, it turns out that a lo of how we (humans) perceive flavor has nothing to do with the food. The ambiance, how we're feeling that day, etc. affect perceived flavor substantially. Keep this in mind, since you're not using e.g., a salinity meter, its possible you're chasing down differences that aren't due to the food itself.