I like making soups and porridges. I usually add salt and pepper at the beginning to add flavor. Recently, a friend gave me a bottle of soy sauce and Im experimenting with it.
What would it make more sense? to add the soy sauce with the other ingredients before the mix boils, while boiling or only to add it before serving?
Another question is: should I use salt if I use soy sauce? Apparently, this sauce has a lot of sodium.
Its flavor is pretty indestructible, you can add it any time you like. If you add it early to any dish with solid materials (meat, veggies, etc) then its flavor will get more into the pieces you're cooking. Oh and yeah if you're adding soy sauce then DEFINITELY add less/no salt in addition
As a slight correction, it can be. If you are using a cheap soy sauce it doesn't matter because there are fewer volatile flavour compounds to cook off and is fine to cook with. If you are using a high end soy sauce, it should be used as a finisher, once the heat is off and food slightly cooled. It's because high-end soy sauce is actually fermented, and for a long time. Because of this it has a much more complex flavour profile and many more compounds that deepen it's taste, compounds that are volatile and will cook off when cooking.
It's an identical concept to extra virgin olive oil and pure olive oil. If it's pure there's few compounds to cook off and retains it's (neutral in this case) flavour. If it's extra virgin the complex aromas and compounds are cooked off when heated and becomes indistinguishable from pure oil.
They are similar enough to be used in the same manner. If you prefer the tamari's flavour more than "cooking" soy sauce then you can continue using it.
Food is your art and you can do whatever the hell you want with it. I did a fair amount of "fine dining" but that never stopped me dipping my fries in milkshakes or eating char sui with a side of American turkey stuffing. I'd never dare serve it to guests but you have lots of freedom nonetheless in cooking.
Also small exception, if it's really expensive tamari then it's best used for finishing. Any soy sauce can be cooked with, it's mostly economical reasons to use the cheap kind. When cooked (and flavour slightly degraded), soy sauce is often a slightly mellow background flavour, and expensive soy sauce does not enhance it very much.