Who doesn't love a marshmallow on the campfire? Marshmallow fillings and s'mores creations are all the rage food trends this year, popping up on menus and shelves everywhere. It seems people never tire of this nostalgic candy. Just in time for summer, let's take a look at the food chemistry behind these unique treats.
History of the marshmallow
Did you know that the marshmallow is actually a plant? That's right, the Althaea officinalis, or marshmallow plant, contains a thick, gooey substance in its roots full of various carbohydrates that ancient and modern cultures have used to make sweets. Today, however, other ingredients are used to create a gel and the soft, foamy texture of the marshmallow.
The ingredients of a marshmallow are quite simple: gelatin, water, sugar, corn syrup, salt, vanilla, powdered sugar and corn starch. Some marshmallows may also contain Egg whites for structure and strength.
What is gelatin? Gelatin is a protein found in animal collagen. It is used as a gelling ingredient which creates very strong gels and provides a food grade "melt in the mouth".
You might be wondering why most desserts have it. many. sugar. Believe it or not, there are often more than the taste.
Take marshmallows, for example, there is a lot of sugar in these candies. In fact, they contain over 50% sugar. So what if you reduce the amount? What would happen?
Let's break it down. Sugar is often the mass of a recipe. Therefore, if you were to remove large amounts, it would have to be replaced with something else to get the same yield of product. He makes food tender and help to incorporate air. High sugar content also helps extend the shelf life of the product through decreased water activity, or water available for microbial and chemical reactions.
Reducing the sugar content will cause the marshmallows to flop. Literally.
Well, marshmallows are a special kind of Colloidal dispersion called a foam. A foam is air suspended in a solid. In this case, the Gelatin the protein expands to trap air in the liquid matrix and create a solid gel.
Guess what helps strengthen the gel and keeps that air in suspension? You guessed it: sugar! Without sugar, the the frost will weaken and air bubbles do not remain dispersed in the solid gel matrix.
To put it to the test, I developed a formula, or scalable and reproducible recipe, based on this recipe by Alton Brown. I then adjusted this “control” formula to reduce the total sugar in the recipe by 25%.
The objective: to understand the role of sugar in the foam. Can the sugar be removed and create the same end result?
To make the marshmallows, first, the gelatin is hydrated with cold water. Cold water is needed to allow the gelatin to hydrate and dissolve. If placed directly in hot water, the gelatin will clump together.
Then the water, sugar, corn syrup, and salt are heated to 240F to create a sweet syrup Solution. This temperature is important to ensure that the right amount of water is present in the syrup. Heating to this high temperature creates a supersaturated solution that contains more sugar than it would normally get on cooling.
In marshmallows, different types of sugar are used in combination. Table sugar is a source of disaccharide sucrose, while corn syrup is the monosaccharide glucose. Glucose is important for the formula because it prevents recrystallization of sugar in candies which would otherwise cause a coarse, grainy texture. Gelatin also helps prevent the sucrose in the syrup from recrystallizing and ensures a smooth texture.
The syrup is then slowly added to the gelatin and beat at high speed for 13 minutes. High speed mixing allows you to incorporate as much air as possible in the product.
Once the mixture is well whipped, it is spread out on a square dish or cutting board and left to together at room temperature for about 4 hours. This creates foam or air in a solid.
You can then cut the marshmallows into any shape you like!
Control marshmallows are better than store bought! They have more flavor and a tender, melting texture. Marshmallows are light and airy. They hold their shape well.
If you are curious about the science of candy making, this would be a good place to start!
Now for the reduced sugar marshmallows.
As soon as the marshmallow test is complete, mix. I know something is different. The sugar mass is solid, dense and clings to the whisk, while the control marshmallows were bright, light and almost pourable (see above).
After the 4 hour period, I cut the marshmallow bricks into squares and rolled them in powdered sugar. Take a look at the cross section below for the results.
Marshmallow with 25% reduced sugar. Air cells are less uniform and unstable in the foam causing liquid to ooze
You can see the Optimized Sugar Control Marshmallows are light and airy with an even distribution of air bubbles. Reduced sugar marshmallows, on the other hand, are less airy, dense, and are already starting to ooze liquid.
These marshmallows are less flavorful and very gooey, still taste great and have a decent texture, but they definitely won't be stable enough to last very long.
What's going on?
Remember, marshmallows are a mousse, which means air bubbles are continuously trap in one liquid matrix (and possibly solid) gelatin protein.
Protein in gelatin unravel once the hot sugar syrup is poured. When the gelatin begins to set after whipping, it traps air bubbles between the protein strands. Proteins also work well surfactants, or stabilizers, and can form stable gels on their own. However, they are even stronger when sugar is added.
Sugar helps strengthen these interactions between the liquid and gas phases and creates stability. Sugar reduces the rate of drainage of fluid by increase viscosity (or thickness) of the liquid phase.
Without the right amount, air is not trapped in the foam to create a light texture. Marshmallows are not stable and the gel is more likely to collapse.
Why does the campfire make marshmallows gooey?
When you roast your marshallow over an open flame, there is a lot of chemistry involved. Sugars are heated to high temperatures, resulting in caramelization. This creates the golden brown color on the outside and many new aromatic compounds.
The sugars called Reducing sugars are necessary for the caramelization we see on the crust. Monosaccharides such as glucose and fructose reduce sugars, unlike sucrose (table sugar). This only happens when the sugar is heated to high temperatures.
Meanwhile, as the heat of the fire continues to heat the marshmallow, the gelatin proteins begin to melt and unfold. This releases the trapped air, leaving a delicious sticky center.
The same thing happens in your mouth when you eat a marshmallow at room temperature. The melting point of gelatin gel is very low and it begins to separate immediately once it touches your tongue. This is why marshmallows have a gooey texture in the mouth.
There's actually a lot of chemistry and science involved in food, even in something as simple as marshmallows. Reducing the amount of sugar is not as easy as it sounds and even small reductions can have a big impact.
Food scientists need to understand the role of ingredients and production techniques to test new ways to produce products with less sugar.
Brown, A. 2014. Homemade marshmallows. https://altonbrown.com/homemade-marshmallow-recipe/
Damodaran, S., Parkin, KL, Fennema OR 2008. Fennema's Food Chemistry Fourth Edition. CRC Press Taylor & Francis Group.
Whether you regularly whip up Michelin-worthy meals at the drop of a hat or your cooking skills are best described as “fine, ” you can always benefit from the helpful little tricks of others. Here, 14 of our friends’, families’ and coworkers’ most-used cooking tips.
There’s a time and a place to whip out that complicated coq au vin recipe you’ve been dying to try. A dinner party isn’t that time. With a new recipe, you’ll likely be chained to the kitchen the whole time, plus, when you’re trying something for the first time, there’s always the possibility that it could go horribly wrong. When cooking for a group, we always err on the side of tried-and-true crowd-pleasers.
You do hours of prep work on an intricate dish, only to be totally disappointed once you taste the terminal product. Bummer. Instead of putting in all that effort only to be disappointed, taste while you cook. That way, you’ll realize sooner that the dish isn’t tasting how you’d like it to, and you can make all kinds of last-ditch efforts to save it. This doesn’t just work for bad-to-OK meals. Tasting midway through and realizing how perfect a dash of cayenne or a squirt of lemon juice would be can take a great dinner to legendary status.
Plating pasta means tossing some onto a plate and finishing it with a nice dollop of sauce right on the middle, right ? Wrong. Here’s how to take your carbs to the next level : On the stove there should be two pans, one with pasta and one with sauce. Cook the pasta to al dente and transfer it into the sauce. Then, add a little bit of pasta water ( literally just the starchy water the pasta has been cooking in ), which will help the sauce cling to the pasta while also keeping it the right consistency. Perfection.
In the pursuit of the perfect steak, you have to be OK with your kitchen getting a little smoky. That’s because, to get the mouthwatering sear we’re all after, the meat has to be dry and the pan should be pretty damn close to smoking hot. Trust us, it’s worth a few seconds of a blaring alarm.
Most foods are ruined by too much salt. Steak is different. When it comes to seasoning your meat ( before you cook it ), more is more. Use a generous amount of coarse Kosher salt—more than you think you need. Since most cuts of steak are pretty thick, even though you’re using a lot of salt, it’s still only covering the surface.
This one isn’t too complicated. Whether you’re making avocado toast, pizza, fried rice or a burger, the addition of a fried egg on top will not hurt your feelings. Trust us.
This one seems like a no-brainer, but we’ve definitely found ourselves in a situation where we assumed we knew all of the ingredients that went into chocolate chip cookies only to find out that we had about half the required amount of brown sugar. Ugh. to avoid a mid-cooking grocery-store trip, read the recipe from front to back—carefully—before you start.
Prepping grains in mass quantities is less about taste than convenience. Rice, quinoa and even oatmeal last about a week in the fridge after being cooked. When we’re prepping any one of those, we double up our measurements and store the leftovers, which are then impossibly easy to use up throughout the week. Too tired to make dinner ? Heat up some leftover rice from the fridge and toss an egg on top ( remember ? ). Couldn’t be simpler.
So you fried up a pound of bacon for an indulgent ( read : delicious ) brunch. Great, just make sure you don’t throw out the grease in the pan. Instead, save it in the refrigerator or freezer ( it technically lasts for up to a year, but should be used sooner than that to take full advantage of its flavor ). Then, anytime you’re cooking something you typically prepare in oil, try cooking it in the bacon grease instead. You’ll never want to eat Brussels sprouts the old way again.
You’ve probably heard that whenever a dish is lacking a little something-something, the best thing to do is toss in some salt. But, we have it on good authority that salt isn’t always the answer. When you’re tasting a dish at the end and you think it needs a little oomph, often it just needs a splash of acid ( like lemon juice ) to round out the flavor.
You know the difference between a paring knife and a fillet knife, but do you know how to take care of them ? Or, more importantly, how to use them ? A set of good knives can be the difference between a stressful cooking experience and a great one. First, practice your knife skills. Look up tutorials on YouTube and practice chopping, slicing and julienne-ing. It’s amazing what you can do with your cook time when your prep time is shortened with solid knife skills. Then, once you’ve got your skills down pat, learn how to take care of your set. No one ever achieved kitchen greatness with a dull chef’s knife.
The key to tender, flavorful barbecue and roasts ? Cooking it on a low temperature for a long time. The same doesn’t go for roasting veggies. For crispy, perfectly cooked butternut squash, Brussels sprouts and more, remember the magic number : 400 degrees Fahrenheit. Any lower, and you risk pulling a pan of blah carrots out of the oven. It might seem high, but to get the nice roasted flavor, you need high heat. And while we’re on the subject, stop crowding your veggies in the pan, which will also make them soggy.
You know how just about every cookie recipe suggests that you chill your dough in the refrigerator for at least a few hours, but oftentimes you don’t listen because you just want cookies now ? ! ( Same. ) Unfortunately, this step actually does make a difference. In addition to limiting how much the dough spreads while baking, chilling your dough intensifies the flavors and produces that perfect chewy, crispy matière we know and love.
It won’t do your breath any favors, but never ( ever ) scrimp on garlic. In fact, we typically double the amount a recipe calls for. Apologies to anyone who was planning on kissing us.