Okay. If I’ve ever said a science post is my favorite.. take it back, take it all back now. Butter is my favorite, this post is my favorite, and let’s all go to France and eat some butter.
Now, onto the science.
- Butter is a pretty cool substance, and has been around for a long time! A recipe for butter dating more than 4,000 years ago involves an animal skin, a small hole, and a contraption to swing the bag around a wooden pole until butter is formed! But – in order to get the cream to make butter, you’d have to let the milk sit out and still to let it separate, since the first mechanical butter separator wasn’t invented until around 1900. Why does milk have the potential to do this? It’s a liquid called a ‘colloid’, which means that there are tiny particles suspended in another liquid. For milk, this is a bunch of tiny fat globules. Once you let fresh milk sit undisturbed, you’re allowing all these molecules to float to the top, creating cream. Additionally, these fat globules are responsible for the creamy taste and mouthfeel of cream – they’re too tiny for us to detect as particles, but they bring the texture nonetheless.
- Now, almost all butter is definitely made in factories, but you can still shake some cream up in a jar to see how it works for yourself. The agitation of the cream globules causes them to bundle up together, and eventually they clump up enough to make butter! This takes a lot of agitation though, and can be done in a variety of ways! Easy as pie, delicious as pie, essential ingredient in pie… we’ve got this.
- But – while butter may have had a place in human diets for a while, it’s recently gotten a lot of flack. If you walk by a dairy cooler, any frozen food aisle, or really any aisle at all in any grocery store, you’ll be flooded with low-fat and non-fat options. But, in 2014, an article was released saying that saturated fat (the ‘problem’ with butter) doesn’t actually correlate with heart disease the way that everyone was up in a tizzy about. And to put some buttercream icing on this cake, the study even suggested that in our craze to substitute fat in our diets, with sugars and and empty carbs – which are even worse for us.
Let’s make butter with heavy cream, and eat it all in one fell swoop. Stir some dill in and pile it embarassingly high on country bread if you want to be like me, but, no pressure. Check out this links to get butter-blissed out:
We’re gonna chat about yeast – mostly because I’m still obsessed with bread (see here), but also because yeast is an important part of a lot of home kitchens. I’ve been working on getting a starter for sourdough going – so yeast thoughts are front and center in my mind. Let’s break this down.
To start, there is a difference between yeast and bacteria molecules. Yeast is a fungus. Bacteria are… bacteria. They have fundamentally different properties, extending from the presence of a nucleus, the organization of DNA and how parts of the cell are displayed. While bacteria can ferment, and produce some flavor molecules while they do, the fermentation of yeast is essential for leavening – or raising – bread. So very many factors can affect the fermentation of yeast – and therefore your final bread product.
- Fast or slow? Fast fermentation is desirable in terms of speed – you’ll get to your final product faster. However, for more complex flavors, a longer fermentation is definitely better. Different things can make a dough ferment at different speeds – and all of those factors are primarily what affects fermentation! It’s all about speed.
- The temperature of dough leads to a simple speed equation: the warmer the dough, the faster the fermentation… to an extent. If you put yeast in a hot enough environment (think, 140°F), they’ll just die, and no one wants that. Optimum fermentation temperature is 78°F-82°F. Below that temperature, our bacterial buddies are more favored for fermentation. If you put dough in a fridge to slow down the fermentation process, you can get strong sour flavors – because of the level of bacterial fermentation.
- The amount of salt can also affect the fermentation of yeast! See, we knew salt was important…. didn’t we. Salt slows down (retards) the ability of yeast to ferment. Salt also plays into bread importantly if you choose to do a pre-ferment, which is essentially pre-fermenting a chunk of ingredients before mixing your final dough. The timing of the pre-ferment can be manipulated through salt percentage. Additionally – the amount of sugar can affect how the dough ferments. Some sugars ferment quickly (think sucrose, glucose and fructose… all very common sugars), and some sugars ferment slowly, like maltose. Some barely ferment, like lactose! Different combinations of sugar types can affect how fast dough ferments. Some strains of yeast can grow very well in high-sugar environments compared to other yeasts – though for the home baker it’s usually just normal yeast doing its own thing. The challah bread pictured is a sweet and buttery dough, and my very normal yeast survived just fine in it.
- While it may seem obvious, the amount of yeast can affect the fermentation rate. Generally, the more yeast, the faster the fermentation. But, you have to toe the line with how much yeast you add, since too much can definitely add a rough flavor – think eating spoonful of yeast (gross). If you add too much yeast, your dough might also ‘exhaust’ itself: aka the yeast eats all the food in the dough and has nothing to do! Most recipes call for a smaller amount of yeast and a slightly longer fermentation time in order to offset this problem.
The coolest thing about all of this is once you get comfortable (and if you do, please tell me how, I’m still not 100% there), you can mess around with some of these variables (as well as pre-ferment times, fermentation times in general, and ingredients) to create your very own bread! We all should have the luxury of our own bread. Here’s some links to keep you reading:
- Basic differences between bacteria and yeast…just a good fun fact to throw out at parties.
- Breadmaking 101 on Serious Eats… talking all about proofing and yeast and fermentation and also mostly just about bread. We like that.
- Wild yeast inspires thoughts of sourdough, and still follows the fermentation rules. Here’s a bunch of sourdough inspiration: a list of links within a list of links for all the bread pictures you want to drool at as well as helpful tutorials, troubleshooting, and recipes. Let’s all make bread!
Since gluten is a commonly used buzzword in our food world today, this week we’re going to dive into gluten – what is it, where does it come from, and what’s the deal with gluten and health.
To start – what is gluten? Gluten is the combination of two proteins that are found in flours. When water is added to the flour, the two proteins, glutenin and gliadin, hop together to form a gluten molecule. As gluten develops (as the two proteins join together), dough or batter becomes less lumpy and becomes more smooth, elastic and bouncy. A common trick you might see in cooking shows tests if enough gluten has developed in dough in order to move onto the next stage: the windowpane test. Take a small piece of dough, stretch it between your fingers. If it can form a thin sheet that you can see light through without ripping (a ‘windowpane’), you’re good to go. Your dough has peaked in terms of a balance between stretch and strength.
When that dough is baked, most of the water evaporates, and all you’re left with in terms of gluten is a structure that holds its shape – giving essential shape and structure to bread. Different types of bread-making can result in different types of gluten development and therefore a different final structure in the baked loaf! We’ve got this down – onto the fun stuff.
Clearly, one of the biggest diet crazes right now is going gluten-free. People swear by it for both weight loss as well as increased energy, clearer skin, and any and all things to happen to a human body. To start off, reputable sources like the Mayo Clinic say that a gluten-free diet is not necessary unless you have a disease like celiac or a demonstrated wheat allergy that requires you stay away from gluten. They even go as far as to say that the weight loss often associated with a gluten-free diet is likely just the cause of a pretty restrictive diet – not simply because you’re not eating gluten anymore. I think it is essential to differentiate between good bread and bad bread – since it might just be the cause of all these ‘gluten stomachaches’ we keep hearing about.
- Bread, traditionally, is naturally fermented, like sourdough. In the endless fermentation that produces a loaf of sourdough, in addition to nutrients and vitamins becoming easier for our body to absorb, gluten becomes easier as well. Little microbes that are busy fermenting start to chew stuff up for you, which makes your body handle it a lot easier. And before you get freaked out about microbes in your bread – microbes are everywhere, helping us live and thrive. Check out the links at the bottom for more information and various cool facts.
- So, now that we know sourdough might be easier to digest, why does that make normal supermarket bread different? There is usually no fermentation in supermarket bread – so you are eating completely undigested gluten! That doesn’t feel good on bellies (think about eating a handful of raw flour), and people often associate that with gluten as a whole – but they shouldn’t. Gluten is healthy, and bread often brings about a host of other nutrients as well. Understanding the process by which your bread came to be helps break it down. Even people who have been demonstrated to be sensitive to gluten can often eat naturally fermented sourdough without ill effects. Important.
Now that you’re a gluten expert, go annoy your friends with this. Share the bread love:
- Mayo Clinic breaks down diet myths here.
- History of sourdough, including natural fermentation, health benefits, and an Ancient Egyptian bakery.
- For those of you coming here because of my microbe comment: TED Talk on how bacteria talk, Bonnie Bassler exploded my mind when this came out. Watch and learn.
Whether or not you eat meat, you have to acknowledge that meat plays a big role in society, meals, and lives – including this killer sausage sandwich I got in Treviso, Italy. People gather around the grill on the Fourth of July, grilling and awkwardly greeting family members they haven’t seen since last year. On Thanksgiving, the turkey inevitably causes sadness, pain and suffering as the unfortunate person in charge bastes and bastes and bastes until the holiday spirit is all but washed away. Thankful for turkey? Maybe… or maybe we should just eat stuffing. But why do we eat meat? Why do we cook it? And, what happens if we don’t? Let’s break it down.
- Humans started to eat meat about 2.3 million years ago, which was a significant change in diet. Interestingly enough, you can begin to see changes in markings on fossilized bones of animals – from the tooth marks of whatever predator snacked that day to the less natural looking cuts of tools. This change in diet allowed us to get an explosion of energy – which allowed our brain to gobble up extra energy and grow and evolve. The very act of eating meat contributed to human evolution – and created humans as we know them.
- In general, we cook meat for two reasons: health concerns and ease of digestion. Obviously there are exceptions to the cooked meat rule – including tuna tartare, sushi, and carpaccio – so humans can certainly eat raw meat and fish without deathly repercussions. Let’s dig in.
- We cook meat because our bodies aren’t tuned up to digest raw meat or any raw food – even raw foodies in our world today are often underweight. Take a cat, for example, that can munch on raw mice, birds and forest friends. They not only have a different set of teeth (I know this for a tried and true fact – my cat also tries to munch on me), but they also have different sets of digestive enzymes and processes dedicated to getting the most they can out of raw meat. Additionally, they have much higher levels of acid in their stomachs – so any pesky bacteria get no chance to invade. Humans can digest raw meat – but we don’t pull nearly as many nutrients out of it as when it’s cooked – and our low-level acid stomachs leave us vulnerable to attack.
- Speaking of attack…while some meat is carefully curated to avoid nasty bugs and parasites hiding within – a lot of the meat we produce isn’t, and must be cooked in order to keep us safe. A variety of parasites die once you cook meat through – rendering the meat completely safe to eat. Some of these parasites include Cryptosporidium parvum, Cyclospora cayetanensis and Trichinella spiralis, to name a few. In addition to cooking simply to kill parasites – when we cook food we alter the chemical structure and it tastes better. When you smell cooking meat, baking brownies or even brewing coffee, it probably smells pretty darn good.
Most of you probably knew there was a reason we cooked meat – or were terrified by your moms about washing the chicken cutting board – but now you know some definitive reasons why we cook meat, and our our evolutionary history was affected because of it! Wicked. Here’s some links:
Welcome to the newest weekly installment: smart science. Using my biology, chemistry and environmental science background, we’re going to break down food science topics that are important to know – in language that is easy to understand. I have a couple ideas on back burners, but let me know if there is anything you’d like to know about.
Today, we talk about salt.
Salt is a chemical compound, consisting of an equal number of sodium and chlorine ions that bond together. It’s a natural mineral, and humans have loved it for just about as long as it’s been around – in the olden days, it was a totally hot commodity. But lonely, little salt has a lot more to offer to food than simply providing a salty flavor or decorative touch (I’m looking at you, flaky sea salt). Salt is good for food, and good for us – in the right quantities.
Let’s break it down.
- Salt plays an actual, physiological role in the human body! We carry sodium naturally in our fluids, and it provides stability and allows cells to function as they should. We HAVE to ingest some sodium every single day in order to replace the sodium we lose through sweat and bathroom breaks. Additionally, lots of table salt in the US contains added iodine – an essential compound for human function. Without iodine, you can have some pretty serious thyroid issues. But – salt does not naturally contain iodine – we add it in since it was an easily accessible and widespread way to get iodine to the general population.
When doctors hook you up to an IV, they’re actually using saline solution – not pure water. The saline (read: salty) solution allows your cells to feel at home in the incoming liquid – if it was pure water, your cells would explode – which is wildly counterproductive to your stay in the hospital.
Long story short: you cannot and should not eat a no-sodium diet – it would cause a myriad of health issues. Your awesome body needs some salt to function, despite what you might hear in the news. But – too much salt is just as bad as too little. We’re practicing moderation here.
- Salt helps us keep our food fresh. Salt-curing was a practice used before refrigeration in order to preserve food – and we still do it to certain foods for enhanced taste. Essentially, when you put that level of salt on something, it draws out the water in the product. Itty-bitty microbes need water to thrive, so removing the water removes their source of liquid, and they will die. Score one for humans wanting to live past 25.
- Salt is important for bread – got your attention now, carboholics? As we already know, salt loves water and greedily gobbles it up. In bread, this means that the salt is competing with the yeast for water. The salt has a stronger pull, and in doing so, slows down and regulates the fermentation. Since yeast needs water to ferment – a smaller supply creates a longer fermentation, which lets us make bread with only very simple ingredients. It also allows us to knead dough less (jackpot!), since the longer fermentation creates a better web of gluten, which traps gases and makes a fluffy loaf without serious hands-on time.
Also, salt allows the crust to get a nice color. As we already talked about, salt in dough slows down the fermentation – but it also tells the yeast present to slow their roll with sugar consumption! This lets more sugar hang around for the final bake, where it caramelizes and turns yummy shades of brown.
Salt also provides essential flavor to bread. I spent a semester in Tuscany, where traditionally bread is made without salt, and boy can I tell you – it makes a difference both in taste and in color. All that said – your bread should still have taste without salt, just not the full bready taste we’ve come to know here at home.
There you go – a primer on salt. There’s a zillion more things salt does in baking, cooking, and the human body – and if you’re interested, here’s a couple links:
read up! and happy salting!