diff --git a/book/basics/how-sourdough-works.tex b/book/basics/how-sourdough-works.tex index 787cd02..37748b4 100644 --- a/book/basics/how-sourdough-works.tex +++ b/book/basics/how-sourdough-works.tex @@ -1,7 +1,7 @@ In this chapter, we will cover the basics of how sourdough ferments. First, we will look at the enzymatic reactions that take place in your flour the moment you add water, triggering the fermentation -process. Then, in order to better understand this process, we will +process. Then, in order to understand this process better, we will learn more about the yeast and bacterial microorganisms involved. \begin{figure}[!htb] @@ -44,9 +44,6 @@ Normally, the grain seed shields the germ against pathogens. However, as the grain is ground into flour, the contents of the seed are exposed. This is ideal for our sourdough microorganisms. -% I removed the line referencing yeast as a saprotrophic fungus since you -% cover this later on in the chapter and removing that helps the text to -% flow more smoothly. Neither the yeast nor the bacteria can prepare their own food. However, as the enzymes are activated, the food they need becomes available, allowing them to feed and multiply. @@ -61,8 +58,11 @@ is a key puzzle piece to making better-tasting bread. Sometimes, when you chew on a potato or a piece of bread for a long period of time, you'll perceive a sweet flavor on your tongue. That's because your salivary glands produce amylase. Amylase breaks down complex starch molecules -into easily-digestible sugars. The germ needs this to produce more plant -matter, and your body needs this to kick-start the digestive process. Normally, +into easily-digestible sugars. Your body uses amylase to start the digestive +process. The germ works similarly by using the same enzyme. The amylase +is used to create sugars out of the starch to then produce more plant matter. + +Normally, the microorganisms on the surface of the grain can't consume the freed maltose molecules, which remain hidden inside the germ. But as we grind the flour, a feeding frenzy takes place. Generally, the warmer the temperature, the faster @@ -203,9 +203,6 @@ tweak just by adjusting the speed of your dough's fermentation. \section{Yeast} -% Yeast is both the singular and plural form of the word unless you're -% specifically referencing a plural number of varieties or types, in which case -% "yeasts" would be correct. Yeasts are single celled microorganisms belonging to the fungi kingdom, and spores that are hundreds of millions of years old have been identified by scientists. There are a wide variety of species: So far, about 1,500 have been @@ -240,7 +237,7 @@ The temperatures at which yeast grows varies. Some yeasts, such as 20°C, while others prefer higher temperatures. In general, the warmer the environment, the faster the yeast's metabolism. The variety of yeast that you cultivate in your sourdough starter should work best within the range -of temperatures where the grain was grown and harvested. So, if you are from a +of temperatures where the grain was grown and harvested. So, if you are from a cooler place and cultivate a sourdough starter from a nordic rye variety, chances are your yeast will prefer a colder environment. @@ -292,19 +289,19 @@ enhanced protection against mold and other pathogens. Indeed, it is in the best interest of the epiphytes to keep their host plants alive for as long as possible \cite{leaf+surface+sugars+epiphytes}. -More research is conducted every day in ways that yeasts can be used as +More research is conducted every day into ways that yeasts can be used as biocontrol agents to protect plants, the advantage being that these bio-agents would be food-safe as the relevant strains of yeast are generally considered harmless to humans. The yeasts would grow and multiply on the leaves, -esentially shielding them from other types of mold. This could be a potential +essentially shielding them from other types of mold. This could be a potential game changer for vineyards that suffer from mildew. Such bio-agents could also be used to shield plants against the psychoactive ergot fungus, which likes to grow in colder, more humid environments and -poses a significant problem for rye farmers. Because it infects the grain -and makes it unfit for consumption due to its high toxicity to the liver, -lawmakers have recently reduced the amount of allowed ergot contamination in -rye flour. +poses a significant problem for rye farmers. +Lawmakers have recently reduced the amount of allowed ergot contamination in +rye flour because it infects the grain and makes it unfit for consumption due +to its high toxicity to the liver. Yeasts could help to mitigate ergot contamination. There is another interesting experiment performed by Italian scientists that shows how crucial yeasts could be in protecting our crops. First, they made @@ -325,9 +322,9 @@ so that they could penetrate the tissue of the plants. The other most dominant microbial antagonists in your sourdough are bacteria. In fact, they are so dominant that they outnumber the yeast in your dough 100 -to 1. Whereas yeast provide leavening power, bacteria create the distinct +to 1. Whereas yeast provides leavening power, bacteria create the distinct flavours for which sourdough has been named. These are due to the acidic -byproducts that result from bacterial feeding. As an added bonus, these acids +byproducts that result from bacterial feeding. As a bonus, these acids can significantly increase the shelf life of sourdough breads. \cite{shelflife+acidity} @@ -375,12 +372,13 @@ fully grown around the bacterial patch, preventing it from spreading further. I imagine a similar scenario could be playing out in our sourdough starters, although, given that the sourdough environment tends to be more liquid, this fight would have to take place everywhere in the dough and not just in an -isolated patch. More research on this topic is required to better understand +isolated patch. More research on this topic is required to get a better understanding of the details of the relationship between yeast and bacteria. + One other interesting trait of sourdough bacteria worth mentioning is their ability to break down and consume the proteins in your dough. If you've baked -sourdough before, chances are you've experienced this first hand. You'll recall +sourdough before, chances are you've experienced this firsthand. You'll recall from the \emph{Enzymatic reactions} section that protease breaks down the gluten network in your dough, resulting in a sticky mess if left unbaked for too long. The bacteria, too, consume and break down the gluten in your @@ -436,4 +434,4 @@ taste of the resulting bread. One last footnote worth mentioning: Some sources say that fermenting at a lower temperature can increase acetic acid production, while fermenting at a warmer temperature can boost lactic acid production. I could not verify this -in my own tests. More research is needed on the topic. +in my own tests. More research is needed on the topic. \ No newline at end of file diff --git a/book/makefile b/book/makefile index 8fce9f4..d760bf9 100644 --- a/book/makefile +++ b/book/makefile @@ -42,6 +42,8 @@ clean: rm -rf book-epub/ rm -rf book-epub3/ rm -rf book-mobi/ + rm -rf book-azw3/ + rm -rf book.azw3 rm -f *.pdf rm -f output.log rm -f content.opf