Salt is a critical bread recipe ingredient, so make sure you do not leave it out or reduce it; as in all cooking, it brings out flavor, both directly and indirectly. It also moderates (slows) the action of the yeast and during fermentation, allows it to produce carbon dioxide (C02) at a reasonable rate, resulting in a better texture.
Salt also helps stabilize and toughen gluten, strengthening it for shaping, keeping it elastic in an acidic environment (bread doughs are acidic), as well as contributing to moisture retention (saltless bread is drier). This effect still takes place in gluten free dough. By using a blend of gluten free flours, the salt treats their qualities and protein content in the same manner to gluten.
Just the right amount of salt also aids in making the crust crisp and preserves the natural off-white color of the flour by protecting against over-oxidation during the mixing process. Without salt, the crust will remain pale.
However, you have to be careful when you add it - if salt comes into direct contact with the dissolved yeast, it will kill it, so be careful to mix the salt in with the second or third cup of dry ingredients.
But, with instant yeast it's not as much of a problem because this type of yeast is coated. However, the amount of salt can be used to control the fermentation process - more salt slows yeast activity. It's best to add in the amount specified in the recipe, rather than adjust it.
Table salt is perfect to use for bread making because it dissolves readily, and sea salt (not the coarse variety) can also be readily exchanged for it.
For 450 grams of flour use 1 1/4 tsp of salt.