I’m reading the largely lucid explanation of yeast, but here’s the main bits where I got stuck:
Where there’s dense storage of energy, there’s often leakage. Sometimes a seed gets split open for some reason, and there’s a bit of digestible carbohydrate exposed on the surface. Where there’s free energy like this, microbes evolve to eat it.
Some of these microbes, especially fungal ones, produce byproducts that are toxic to us. But others, such as some bacteria and yeasts, break down hard-to-digest parts of wheat into substances that are easier for us to digest.
The first paragraph I get; in my world-model, there’s a generic evolutionary pressure that optimises for this kind of thing at different levels—here it’s microbes coming to eat the carbohydrates. And then some of them produce toxic by-products, which makes sense, I imagine most chemicals aren’t that great for humans to eat.
But then some of them… why do they break down the ‘hard-to-digest parts’? And why does this follow from a section about microbes eating carbs, which I presume (not really knowing quite what carbs are except that humans are supposed to eat them) are not ‘hard-to-digest’ parts of wheat?
I suppose I have a model where there are hard to digest parts, and easy to digest parts, and you’re saying that if the hard to digest parts get broken then microbes come for the easy to digest parts. But apparently some microbes come for the hard-to-digest parts too, and turn them into easy-to-digest-for-humans parts.
That makes sense, but then I’m confused about why you wrote that after saying that microbes come to eat the juicy insides *after* the outside tough parts are removed.
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Then, the next bit reads:
Presumably at some point, people noticed that if they wet some flour and left it out for a day or two before cooking it, the resulting porridge or cracker was both tastier and more digestible. (Other fermented products such as sauerkraut may have been discovered in a similar way.)
Is there an implicit statement here that water broke down the hard-to-digest outside parts and brought the yeast molecules in? I’m not sure I know much about fermentation or what it is to follow that bit.
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I don’t know really what carbohydrates or fermentation are, and that maybe prevented me from reading clearly.
why do they break down the ‘hard-to-digest parts’?
The only explanation I have to offer here is a selection effect. Mostly when something is food to us, other creatures compete with us for the food and we want to ward them off. Occasionally we find something that transforms nonfood to food, and encourage it to grow. Crops are one example. Ruminants are another. The microbes that grow on grain are another.
Is there an implicit statement here that water broke down the hard-to-digest outside parts and brought the yeast molecules in?
It’s the breaking up of the wheat kernel in grinding flour that makes more of the energy available (vs the occasional leakage you might expect to happen without human intervention), by opening up the capsules it’s in. But water is also needed for metabolism, so until you wet the flour the naturally occurring grain-eating microbes can’t take much advantage of this.
I’m reading the largely lucid explanation of yeast, but here’s the main bits where I got stuck:
The first paragraph I get; in my world-model, there’s a generic evolutionary pressure that optimises for this kind of thing at different levels—here it’s microbes coming to eat the carbohydrates. And then some of them produce toxic by-products, which makes sense, I imagine most chemicals aren’t that great for humans to eat.
But then some of them… why do they break down the ‘hard-to-digest parts’? And why does this follow from a section about microbes eating carbs, which I presume (not really knowing quite what carbs are except that humans are supposed to eat them) are not ‘hard-to-digest’ parts of wheat?
I suppose I have a model where there are hard to digest parts, and easy to digest parts, and you’re saying that if the hard to digest parts get broken then microbes come for the easy to digest parts. But apparently some microbes come for the hard-to-digest parts too, and turn them into easy-to-digest-for-humans parts.
That makes sense, but then I’m confused about why you wrote that after saying that microbes come to eat the juicy insides *after* the outside tough parts are removed.
---
Then, the next bit reads:
Is there an implicit statement here that water broke down the hard-to-digest outside parts and brought the yeast molecules in? I’m not sure I know much about fermentation or what it is to follow that bit.
---
I don’t know really what carbohydrates or fermentation are, and that maybe prevented me from reading clearly.
The only explanation I have to offer here is a selection effect. Mostly when something is food to us, other creatures compete with us for the food and we want to ward them off. Occasionally we find something that transforms nonfood to food, and encourage it to grow. Crops are one example. Ruminants are another. The microbes that grow on grain are another.
It’s the breaking up of the wheat kernel in grinding flour that makes more of the energy available (vs the occasional leakage you might expect to happen without human intervention), by opening up the capsules it’s in. But water is also needed for metabolism, so until you wet the flour the naturally occurring grain-eating microbes can’t take much advantage of this.