The Science of Bread (Part 2) - The Bread Making Process - Yeasted Bread

[@user-ej8yz5er6l]

Really enlightening and explains the chemistry of many phenomena that I have seen but not been able to explain!

[@angelicateal4504]

I have a degree in Food Science but I did very little of it. Your videos are reminding me of all those classes I took and bringing them to life in a much clearer way. I am crazy for bread and recently decided to learn as much as I could about bread baking, so this video is just what I wanted. Thank you so much. Have you written a book?

[@iamcookbook]

I love this! I've been making bread and pizza dough for years but didn't understand the chemistry. Your videos help a lot!

[@patrickkish6662]

Watching this on a phone without glasses, 19:05 looks like Sanskrit and a mandala. That aside, I wonder why people don't listen to soil scientists nowadays? Being microbially aligned seems to be the trick of the Earth's tale. Anyhow, thanks for the educational and inspirational series. Weighing our self worth, strengthening our bonds, and rising before we solidify, and nourish. Yep. The ol' energetic dance of loaf and life 🍞 🌎 ❤️

[@rachelsfoodventures54]

I corrected the subtitles in English and added some other languages! I am also fixing the subtitles on my other bread science videos.

[@mariastevens6406]

Just tried it with this video and your first one on this series, today, and already have more confidence in learning this stuff. It turned out amazing! Thank you so much for this.

[@rachelsfoodventures54]

That's excellent!!!

[@4guysandacontroller]

Thank you so much this video really helped me understand what I'm doing much better

[@fssaifanclub4398]

Superbly explained in concise formats, really helpful to my students 👌👌👍🙏

[@MasterJake777]

I'm really enjoying these bread science videos, thanks so much! I recently read the Bread Science book by Emily Buehler and left wanting a lot more. One thing I was wondering about: you mentioned sugar will absorb water molecules that would ordinarily form gluten. Why wouldn't the invertase just convert the sugar to glucose, further aiding in gluten development instead of inhibiting it?

[@rachelsfoodventures54]

So your question is essentially that invertase will stimulate gluten formation by consuming sugar that would otherwise inhibit, or slow gluten formation. I may not be able to fully answer your question, both because I can't know exactly what goes on in every loaf of bread, and I haven't found a lot of reputable resources directly related to this topic. But I will address the relationships and perhaps you can fill in the blanks. Let's consider the sugar and gluten relationship. Gluten, starch, and sugar all compete for water when a dough is forming, but the sugar will most likely win that competition. Good thing is that most doughs have significantly more flour (gluten and starch content) than sugar, so the sugar cannot inhibit gluten formation completely in this case, instead it tends to slow it down. (Side note: there are conflicting resources that say sugar inhibits or just slows gluten formation, and my conclusion is that it just slows gluten formation as long as there isn't too much sugar.) This slowing down of gluten formation is a good thing because if all the gluten forms you can get a denser, stronger, chewier product, whereas sugar helps soften and tenderize the dough to some degree. So how much sugar you add depends on what result you want in terms of flavor and texture. Obviously, however, sugar isn't the only thing influencing dough texture, since water content, salt content, time etc. also influence texture and rise. The second relationship I will address is the sugar and yeast relationship. There is also a competition between sugar and yeast for water, since yeast need water to grow and continue respiration. This competition is because sugar is hygroscopic, so it can hold and absorb moisture, witholding it from the yeast. So, although yeast need sugar or starch to activate, excess sugar can impede yeast activity. Furthermore, remember that too much alcohol inhibits yeast growth, therefore if too much sugar is consumed and the loaf is overfermented you will get a boozy taste in your bread, and although the gluten and structure may be fine (depending on how overfermented it is) the taste will be somewhat beerlike, which isn't desirable, and the dough may have a weird texture. I'll also share a couple possible scenarios that may occur in real life. So let's think of a bread dough with a small amount of sugar--a standard white sandwich loaf. It's mixed well and although the sugar absorbs some water there's still plenty left for sufficient gluten to form to make a nice loaf of bread, and this is a good amount of sugar for the yeast to consume and this aids in leavening. But imagine the same dough but someone accidentally added 20x as much sugar in there, keeping all other ingredients the same. Sure the gluten will form but probably not as well as the first dough since the large amount of sugar will likely absorb far too much water. This dough will likely appear dry and it's unlikely that the yeast will be distributed well if the dough is dry. Therefore with so much water taken up by the sugar, the yeast will activate somewhat and feed off the sugar, but there won't be enough water for respiration to continue, and the yeast will be inhibited. So to address your specific question, I can't give a straight answer. My first assumption is that invertase and gluten activate at the beginning of dough formation when using a commercial yeast. Since yeast is usually activated in sugar water then yes the invertase will consume some sugar, making water more available for gluten development, and this may take some time, so the gluten is slowed but not inhibited. However, consuming all the sugar may make the loaf less pleasant to eat if a strong alcohol flavor is produced.

[@MasterJake777]

@@rachelsfoodventures54 Thanks so much for the detailed reply! What you said about the tug-of-war between yeast needing water and sugar absorbing water (plus yeast eating sugar) makes total sense and is very interesting. I guess everything is checks and balances after all.

[@makinggreatbread]

Since you are clearly geeky, consider doing bread experiments. Nice videos so far. Thanks.

[@DavidBertossi]

Great explanation, do you have any idea of why boiling flour in water results in a very unpleasant, bitter aftertaste as if i were eating some raw flour? I've tried plenty of times and with different types of flour with the same bad result, they are not rancid as i have used it for other uses and they are good. 100g flour added to 900g water for boiled for 50 minutes, constantly stirring until it's a thick paste. Appreciate your reply!

[@thedoggedscientist]

The only explanation could be that boiling in water help to release poly-phenolic compounds from the flour and some of them could be bitter. Poly-phenolic compounds are soluble in water.

[@DavidBertossi]

@@thedoggedscientist That's interesting, i don't have much chemistry knowledge but i found out that i needed to stop stirring the mixture, if i let it boil for 10 minutes, then stir for a couple of seconds, and again boil for 10 minutes, stir, repeat until about 50 minutes have passed, then not only the texture but also the flavor becomes much better and starts tasting like food

[@shawntepitts488]

OH Gosh