Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff
Speaker 1: Lauren Volgebon Here. You might think that you try to
Speaker 1: avoid microorganisms in your food because bacteria and fungi cause
Speaker 1: food to spoil. But the truth is we wouldn't have
Speaker 1: a lot of the world's favorite foods and beverages like coffee, chocolate, vanilla, cheese, bread, beer,
Speaker 1: and cured meats, just to name a few, without fermentation,
Speaker 1: which involves the intentional use of microorganisms to transform food.
Speaker 1: The line between spoiling and fermentation is a muddy one,
Speaker 1: but a distinction humans have been fuzzing with for millennia. Generally,
Speaker 1: when we say that food has spoiled, what we technically
Speaker 1: mean is that microbes have started eating it before we've
Speaker 1: had a chance to, and that they've made the texture
Speaker 1: and or flavor unpleasant to us. And if those microbes
Speaker 1: are pathogenic, eating that food could even make us sick.
Speaker 1: When we ferment food, we're employing helpful, nonpathogenic microbes to
Speaker 1: spoil it on purpose before harmful microbes can get to it.
Speaker 1: For the article, this episode is based on How Stuff Work.
Speaker 1: Spoke with sand Or Cats, a teacher and author of
Speaker 1: several books about fermentation. He said, what microbiology has illuminated
Speaker 1: is that all the plants and animal products that make
Speaker 1: up our food are inevitably populated by a diversity of microorganisms.
Speaker 1: Fermentation involves encouraging the growth of some microorganisms, ones that
Speaker 1: make our food more stable, more delicious, more nutritious, safer,
Speaker 1: less toxic or alcoholic, and thereby prevent the growth of
Speaker 1: the ones that can decompose our food or make us sick.
Speaker 1: Every known culinary tradition in the world uses fermentation in
Speaker 1: some way or another. Humans began using fermentation to brew beer,
Speaker 1: preserve food, and make their food tasty, and render toxic
Speaker 1: things edible millennia before Louis Pasteur proved that living cells
Speaker 1: were responsible for fermentation. Akatz said the oldest examples of
Speaker 1: fermentation in the archaeological record are from about ten thousand
Speaker 1: years ago in China, though I would argue that tells
Speaker 1: us more about the history of pottery than the history
Speaker 1: of fermentation. Presumably, the cultural practice of fermentation is older
Speaker 1: than that using pits of the ground, gourds, animal membranes, wood,
Speaker 1: or other biodegradable materials. It's no surprise that fermentation can
Speaker 1: be traced back to around the same time as humans
Speaker 1: began developing communities around agriculture. In order for it to
Speaker 1: make sense for us to invest all our time and
Speaker 1: energy into growing plants and livestock for food instead of
Speaker 1: hunting and gathering, humans would have had to come up
Speaker 1: with a strategy for storing and preserving food so that
Speaker 1: the harvest of a few weeks could last the community
Speaker 1: many months. Also, basically every culture in the world has
Speaker 1: figured out how to ferment sugars into alcohol. It's possible
Speaker 1: that our primate ancestors understood the party inducing effects of
Speaker 1: eating a bunch of fermented fruit that they found on
Speaker 1: the ground. It helps that the yeasts that turn sugars
Speaker 1: into alcohol grow wild in the air and on the
Speaker 1: skins of many fruit. All humans had to do was
Speaker 1: figure out how to do this on purpose. The word
Speaker 1: ferment comes from the Latin word for boiling or rising,
Speaker 1: which makes perfect sense if you've ever seen beer brewing
Speaker 1: or bread dough rising. The bubbles and beer and pockets
Speaker 1: of air and bread both come from the action of
Speaker 1: yeasts living. The applied science of zymology is the study
Speaker 1: of how microorganisms ferment these stuff around us. Oh, what
Speaker 1: the biochemical processes are which specific organisms are doing it,
Speaker 1: and how this works all over the world, including in
Speaker 1: our foods. There are three base types of fermentation that
Speaker 1: can happen in the foods and drinks we enjoy every day.
Speaker 1: Alcoholic fermentation has been a fan favorite for millennia. It
Speaker 1: uses yeasts to convert sugars in plants like grains or
Speaker 1: fruit into ethanol, carbon dioxide, and other byproducts, some of
Speaker 1: which we experience as flavors. Humans invented alcoholic beverages before
Speaker 1: we invented the wheel. Then there's acetic acid fermentation, which
Speaker 1: happens after yeasts finish their alcoholic fermentation and acetic acid
Speaker 1: bacteria take over. These bacteria ferment sugars and ethanol into acids,
Speaker 1: are resulting in things like vinegar and kombucha. Last, but
Speaker 1: not least, there's lactic acid fermentation, which is the microbial
Speaker 1: magic behind so many of our favorite foods, from sour
Speaker 1: dough bread to kimchi to yogurt, plus many types of cheese.
Speaker 1: Lactic acid bacteria convert simple carbohydrates into lactic acid, a
Speaker 1: process that turns sweet things sour, which is what gives
Speaker 1: all of the above foods their characteristic kick a note
Speaker 1: that often the fermented foods we eat rely on more
Speaker 1: than one of these processes. Some beers are flavored with
Speaker 1: help from lactic acid bacteria. Pickles can be made either
Speaker 1: with lactic acid bacteria or vinegar, or a combination of both,
Speaker 1: and things like chocolate and coffee get some of their
Speaker 1: characteristic flavor from a combination of all three. But these
Speaker 1: processes don't just make food tart or tasty or alcoholic.
Speaker 1: They also make them last longer. You know, cheese stays
Speaker 1: good longer than milk. But part of what's so cool
Speaker 1: about our ancestors using fermentation on food is that, thousands
Speaker 1: of years before we understood what microbes or nutrients are,
Speaker 1: we were using microbes to unlock nutrients. The microorganisms that
Speaker 1: ferment our food essentially break down things like carbohydrates, proteins,
Speaker 1: and chemical bonds in our food before we eat it,
Speaker 1: in some cases, making it more easily digested or its
Speaker 1: nutrients more bioavailable. That's why someone with the lactose intolerance
Speaker 1: might be able to eat in aged cheese with no issue.
Speaker 1: The lactose or milk sugar will have been almost entirely
Speaker 1: broken down by bacteria. During the aging process. Fermentation also
Speaker 1: generates additional bee vitamins in many foods and cave vitamins
Speaker 1: in some. Furthermore, some foods can only be made edible
Speaker 1: at all through fermentation. The microorganisms take potentially toxic to
Speaker 1: us compounds and digest them into harmless or even beneficial forms,
Speaker 1: rendering foods that could otherwise be poisonous or irritating safe
Speaker 1: to eat. One example of this can be found in
Speaker 1: cassava tubers. They contain high levels of cyanide when they're
Speaker 1: harvested and require fermentation to make them safe to eat.
Speaker 1: One popular health claim made about some fermented foods is
Speaker 1: that they contain probiotics, which are live microorganisms that are
Speaker 1: supposed to help our digestive systems and or our gut
Speaker 1: microbiome function better. Unfortunately, science hasn't been able to prove
Speaker 1: those claims yet. Our bodies are complicated and more research
Speaker 1: is necessary there. As with any food or drink, we
Speaker 1: hear brain stuff think that you should consume fermented products
Speaker 1: if you like them. Katz said certain ferments, such as
Speaker 1: strong cheeses, are edgy, and that some people find them
Speaker 1: compellingly delicious, while others think that they're disgusting and are
Speaker 1: reminded of decomposition and death. Science offers us no sharp
Speaker 1: dividing line between fermentation and spoilage. In most cases, it's obvious,
Speaker 1: but in certain cases it's culturally determined and subjective. Today's
Speaker 1: episode is based on the article food Fermentation How microorganisms
Speaker 1: make Food Delicious on HowStuffWorks dot com, written by Jesselynshields.
Speaker 1: For lots more about how food fermentation works, check out
Speaker 1: my other podcast Saver brain Stuff is production of iHeartRadio
Speaker 1: and partnership with how stuffworks dot Com, and is produced
Speaker 1: by Tyler klang A. Four more podcasts my heart Radio,
Speaker 1: visit the iHeartRadio app, Apple Podcasts, or wherever you listen
Speaker 1: to your favorite shows.