Free Bread Matters by Andrew Whitley Page A

throughout the Near and Far East, Europe and North Africa from 10,000 to 4,000 BC, when the ‘naked’ wheats (i.e. those in which the husk separates from the kernel during threshing) began to take over. Emmer remains an important crop in Ethiopia and some is grown in India and Italy. Both einkorn and emmer are significantly higher in overall protein than modern wheat and have a good flavour. They have a slightly sticky gluten and produce loaves of smaller volume than modern flours.
    Grains and flours suitable for gluten-free baking are discussed in Chapter 12.
    Water
    For most practical purposes, any normal mains water supply will be fine for baking, with no perceptible differences between hard and soft water areas. At the extremes, very hard (alkaline, with a high calcium content) water may tend to reduce the rate of yeast fermentation and tighten the gluten in a dough, whereas very soft water may produce a stickier result. But unless you move between areas with widely differing water types, you will probably not notice any particular effect – or rather you will get used to working with what you have got. The one exception to this is in the production of natural leavens and sourdoughs. Some domestic supplies are quite heavily chlorinated and, since chlorine kills almost all bacteria (that’s why it’s there), it is advisable to filter your mains water or use still spring water from bottles, particularly in the early stages of starting a natural fermentation. Leaving mains water in a bucket or jug overnight removes most of the chlorine.
    Yeast
    Yeast is what makes dough rise. By feeding on simple sugars obtained from the flour, it produces carbon dioxide (CO 2 ) gas and alcohol. The gas inflates whatever gluten network has developed in the dough; most of the alcohol is evaporated at the baking stage. Baker’s yeast is the term used to describe industrially produced, highly concentrated sources of yeast, which are supplied either liquid (for large bakeries), fresh or dried in various forms. Leavens or sourdoughs are cultures of naturally occurring yeasts and lactobacilli. They are dealt with in more detail in Chapter 7.
    Yeast is a single-celled micro-organism belonging to the fungi family. It has a porous skin through which materials dissolved into small molecules pass to ‘feed’ the organism. The yeast cell releases 14 different enzymes, which help break down carbohydrates into forms that are accessible. Yeast reproduces by ‘budding’, or dividing into identical cells. If it becomes dry, it forms spores, which can last in the environment for a long time.
    There are hundreds of genera, species and strains of yeast. Baker’s yeast is Saccharomyces cerevisiae; the species S. exiguus is often found in acid leavens or sourdoughs. Candida is another genus of yeast. It gets a bad press through its species C. albicans, which, though present and harmless in up to 50 per cent of humans, can in some people produce strains that are pathogenic and cause harmful irritation of the gut and other membranes. However, C. milleri is one of the commonest ‘wild’ yeasts present in natural fermentations; it has a pronounced ability to live in stable association with the lactobacilli that are the other crucial component of sourdoughs 4 .
    Fermentation and reproduction are not the same thing. Yeast fermentation can take place in the absence of oxygen, hence Louis Pasteur’s remark that ‘fermentation is life without air’. The presence of oxygen inhibits fermentation but increases yeast reproduction. This is why yeast manufacturers blow large amounts of air through their fermenters, reducing fermentation, which generates unwanted CO 2 , and encouraging the yeast to reproduce itself. In fast-made bread, there is no time for yeast reproduction to take place, which explains why much larger initial quantities are required to produce sufficient gas to expand the dough. In long fermentations, however, such as an overnight sponge (see