Salt is one of the four essential ingredients in making bread, along with flour, yeast and water. Nothing more is needed, although often a lot more is added.
Salt is listed in all the recipes. Only one bread I’ve ever read about is salt-free (a Tuscan specialty mentioned in William Alexander’s book, 52 Loaves).
We tend to assume salt is simply for flavour, but it is also part of our basic biology:
I find it easiest to think of salt as one half of the body’s water-regulation system, the other half being potassium. The membranes of every cell in the body allow water to flow through in direct proportion to how much sodium and potassium are present in the immediate area. Too much or too little sodium in the body affects everything from digestion to blood pressure to brain function.
Since proper sodium levels are so important, the body uses the kidneys to maintain a precise balance. The system is very efficient, which means that if you eat more sodium than the recommended daily allowance, you’ll simply excrete whatever you don’t need (within reason). That also means that we tend to crave more salt than we actually need to eat, which might explain its flavor-enhancing properties.
Salt, as the site above tells us, suppresses bitter flavours, which means some foods taste better salted (at least in my cultural background, which favours sweet and salty over sour and bitter). Because it suppresses bitter, which in turn suppresses sweet and sour flavours, these flavours come across as stronger in the presence of salt.
Which suggests that a bread with a sweet factor – say raisins, coconut or cranberries – can have a higher salt content than a plain bread, because the salt will enhance the sweetness. So less sugar, more salt? (Okay, I don’t cook with processed sugar because I try to avoid it in my diet…)
Read this food science piece in Nature about salt, food and flavour. Very interesting.
Taste and flavour are not quite synonymous, as the National Institute of Health reminds us:
Taste and flavor are terms that are often confused. The word “taste” has two meanings, one technical and the other as commonly used in the English language, which encompasses the larger concept of flavor…
The sense of taste, one of the five major senses, is defined based on anatomy. In mammals, it is the sense subserved by taste receptor cells located primarily on taste buds in the oral cavity. These taste receptor cells are innervated by branches of the seventh, ninth, and tenth cranial nerves that synapse first in the brainstem prior to sending messages to other parts of the brain…
Virtually all foods and beverages impart sensations in addition to taste. For example, a complex food such as soup not only has taste properties (e.g., it is salty, sour, or sweet) but also has volatile compounds that give it its specific identity (e.g., pea soup compared to potato soup), and it may also have burning properties, such as those caused by hot peppers… In common parlance, the entire sensation elicited by this food is called its “taste.” However, most scientists would instead use the term “flavor” to refer to this total sensation, and that is how it will be used here. It should be noted that many also include the texture of a food as a component of flavor. Taste molecules such as salt can influence flavor in many ways, some of which are described below.
Of course, salt plays other roles in the baking, fermenting and gluten development stages. According to the Wild Yeast blog:
- Salt affects dough texture, making it stronger and less sticky, as the commenter noticed.
- Salt reduces oxidation of the dough during mixing. Oxidation causes the degradation of carotenoid pigments in the flour that contribute to flavor and crumb color.
- Salt regulates yeast activity, causing fermentation to progress at a more consistent rate.
- Salt affects shelf life. Because it attracts water, it can help keep bread from staling too quickly in a dry environment. However, in a humid environment, it can make the crust soggier.