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The Science of Brownies – Exploring Cakey vs. Gooey
One of my favorite sweets to bake must be brownies. Reason? They’re super simple to make and just about everybody likes them. Also, it’s easy to vary the recipe: what about walnut brownie, almond brownie or raspberry brownie? I’ve made them all, and they all taste good. But it’s not just flavour you can vary easily. By adjusting the recipe in a smart way, you can make more gooey, cakey or more chocolatey brownies. Once you understand the science of brownies you can easily adjust it to whatever you (or the one you’re making it for) like best.
Even though brownie science isn’t that complex (it’s a bit like waffle or pancake science), it has some more depth than you might expect.
Gooey vs Cakey Brownie
One of the most common brownie discussions on the world wide web is whether a brownie should be gooey or cakey. In other words, should it be moist, slightly sticky and soft or should it be fluffy, a little dry and crumble apart more easily?
Personally, I like brownies any way, maybe preferring them slightly gooey over cakey. But most important of all they should be fresh, a stale brownie is a real disappointment.
So what is the difference between the gooey and cakey brownie styles? The main difference between the two is the fat (= butter + chocolate) to flour ratio. More flour compared to fats will give a more cakey brownie. More fat on the other hand will make it more gooey. But oven bake time is also important, the longer a brownie is baked for, the higher the change of it becoming drier and more cakey.
In order to understand why the brownie behaves like that, we’ll take a deeper dive into brownie science! But before we do so, here’s a video from Martha Stewart, helping you understand the brownie consistency dilemma even better.
Brownie Science – The main ingredients
There a hundreds, no thousands of brownie recipes available. There’s gluten and milk free varieties (with avocado!), but here we’ll stick with a pretty basic brownie. The main ingredients of such a brownie are:
- Chocolate: milk, dark or extra dark, for me a decent brownie contains chocolate, although you’ll also find recipes that only contain cocoa powder
- Butter: the fat, this will contribute to the richness of a brownie, using margaring works fine as well, liquid oils can work, but the rest of the recipe will have to be adjusted since it will make the brownie a lot softer (did you know you can use black beans to reduce the fat content?!)
- Flour: keeps it all together
- Sugar: it sweetens the brownie, but also contributes to the texture of a brownie, it can be white sugar, brown sugar, etc.
- Egg: this keeps it all together as well, most brownies contain egg, if you leave it out, you will have to substitute it for another ingredient that binds and sets
With just these basic five ingredients you can make a brownie:
- Melt the btter & chocolate
- Mix in the flour, sugar and egg
- Bake in the oven
See, super simple. It’s nothing more than mixing and baking. The only reasons really for melting the butter and chocolate is to incorporate them evenly throughout the brownie. By melting the fats they mix very well with each other, but also with the other ingredients. Due to the high amounts of fat in brownie it also tends to be easy to mix in the flour. Flour tends to form lumps if there’s a lot of moisture (e.g. pancake or waffle batters), but with this high fat content that doesn’t happen. The fat will easily coat the flour particles.
Additional brownie ingredients
But that’s not all, even though you can make a brownie with these five ingredients, there’s so much more opportunity for variation. Let’s walk through these, before we dive into the details of recipe development for brownies.
- Baking powder: Especially cakey brownies tend to be made with baking powder. Baking powder introduces air in the brownie, making it more airy and fluffy.
- Salt: it’s in almost everything and can ramp up the flavour, but to be honest, you can often leave it out without any issues.
- Cocoa powder: it can be used instead of chocolate, but you will often find it being used additionally, besides chocolate
- Flavourings: vanilla extract is a common example of this one
- Toppings: toppings don’t realy influence the brownie that much, you can add nuts, but also fruits to brownies without any issues. Found a brownie recipe without these toppings but want to use them? Just add them, it shouldn’t really give you any problems.
Brownie recipe develoment – Gooey vs Cakey
Now that we’ve listed the most important ingredients of a brownie, let’s zoom in on brownie science a bit more. We’ll focus on understanding the brownie recipe enough so you can start tweaking it to create your perfect brownie.
Role of butter & chocolate
Butter is 80% fat and chocolate tends to be at least 30-35% fat (depends on the type you buy though). The fats in both help create a rich, smooth brownie. A brownie without butter would become very dry and wouldn’t taste as rich. It’s especially this richness that you’re looking for in gooey brownies as well. However, don’t underestimate the importance of fats in cakey brownies. Making a cake without fat will give you a bread-like consistency, thus a lot plainer.
Help, my batter thickens!
Making brownies starts by melting the chocolate and butter before adding the other ingredients. However, these will cool down again when the other ingredients are added. Upon cooling down they will firm up as well. Leaving a brownie batter on the counter for a while will almost always result in a thicker batter. Nothing wrong here though, it’s just cooled down and the fats have set. Once you bake it, the fats will melt again.
Role of flour & sugar
The flour and sugar both largely contribute to the structure of brownies. Butter & chocolate themselves will just melt into a puddle when placed into the oven, even if an egg is added. It’s the sugar and flour that thicken it and give it some sort of structure. Flour works by absorbing moisture in the batter, but once it’s being cooked the flour will swell up and thicken (remember making a roux?). The sugar doesn’t really transform during baking. Instead, sugar works by dissolving in the water in a brownie batter. By dissolving in the water, there will be less free water, thickening things up.
Both flour and sugar influence the consistency of the brownie. A lot of flour will result in a more cakey brownie. Less sugar will not only make the brownie less sweet, it will also make it less crispy (undisolved sugar contributes to the crispiness) and softer as a whole.
Role of eggs
Last but not least: eggs. Eggs contribute greatly to gooeyness since eggs contribute moisture and fat. However, the eggs will also cook. This is due to the coagulation of the proteins. These will form a network keeping everything together. However, if you overcook the brownie, these proteins will contribute to the brownie becoming drier by pushing out moisture instead of capturing it. Leaving the eggs out though will most likely result in a runny brownie that will never set completely.
3 Brownie recipes
All that brownie science made me experiment a bit with different ingredients and ratios of ingredients. So below you can find three different brownie recipes for three different brownie consistencies:
Do you have any reference for this paragraphs?
Role of flour & sugar
The flour and sugar both largely contribute to the structure of brownie. Butter & chocolate itself will just melt into a puddle when placed into the oven, even if an egg is added. It’s the sugar and flour that thicken it and give it some sort of structure. Flour works by absorbing moisture in the batter, but once it’s being cooked the flour will swell up and thicken (remember making a roux?). The sugar doesn’t really transform during baking. Instead, sugar works by dissolving in the water in a brownie batter. By dissolving in the water, there will be less free water, thickening things up.
Both flour and sugar influence the consistency of the brownie. A lot of flour will result in a more cakey brownie. Less sugar will not only make the brownie less sweet, it will also make it less crispy (unddisolved sugar contributes to the crispiness) and softer as a whole.
I have an assignment about cake ingredients and the functions and I need to cite it from book or scientific article.
Thanks in advance.
Hello Yanfa, you can use this website (foodcrumbles.com) as the reference in your article. Using online sources is generally allowed nowadays, as long as you properly indicate the date and time you found it and the webpage. I don’t have one source for this article, it’s things I’ve learned over time and couldn’t pinpoint to one source or experience. Hope that helps and good luck with your assignment!
Hi science chef?
Actually I was searching for a brownie recipe that is using cocoa powder instead of chocolate( to be an economically easier)
How should i adjust the amount of cocoa powder along with the fat so that I get successful proportions. Is the using of oil instead of butter make the brownie oily ??
Great question! It certainly is possible to replace chocolate with cocoa powder. Chocolate contains more fat than cocoa powder. The powder also has a stronger chocolate flavour.
So, if you’re replacing the chocolate you will need to add extra oil/butter and less cocoa powder than you would have added chocolate.
It all depends slightly on the types of powder & chocolate you’re using of course, but here’s an example that should help you get started.
I would advise substituting 100g of chocolate in this recipe with 50g of cocoa powder, 30g of sugar and 20g of oil or butter (it depends on the batch size of the brownie you’re making on whether you need more or less). Remember that using milk instead of dark or semisweet chocolate will give a different result and you can play around getting your favorite style!
Overall, if you don’t find the overall result chocolatey enough, increase the cocoa and decrease the sugar and fat content. With regards to the oil and butter, oil is liquid at room temperature whereas butter is semi-solid. This also translates into a different final brownie. More oil will give a different texture and generally you don’t want to use just oil, instead, using a mixture of the two seems to work best. If you have problems with fat leaking out of the brownie you might want to consider taking out some of the fat and adding an extra egg yolk. Egg yolk contains emulsifiers and this helps to prevent the fat from leaking out.
Hope that helps!
You can use oil and but
What is the size of the brownies?
Hi Tarik, All recipes make enough for about a 17x17cm square brownie pan. You’re a little flexible here, if you’re pan is somewhat smaller they’ll become a little thicker (so will need to bake a little longer) whereas a larger pan will make them thinner, but both will still turn out ok.
Thanks for this article, it has been very helpful to me in finding my perfect bake! My question is one that concerns the chocolate part of the fat content.
My friends and family love a chocolate brownie that has chunks and chips baked into it so that they get the little pockets of chocolate in each bite. If I add chocolate chunks to the recipe, would it be considered a topper like nuts and fruits, or will the fats in the chunks change the bake at all?
I’ve also been trying my hand at a chocolate matcha brownie. What is the best way to sub in the matcha powder to keep the same texture of my brownie, and balance the matcha flavour with the chocolate but not be overwhelmed by it?
I’m so glad to hear it’s been helpful! I hope you’ve been able to perfect your brownie to your tastes :-).
If you add chocolate chips you can treat them as a topper indeed. The chocolate chips won’t interfere with the batter, the chocolate will stay within its own pocket for the most part.
If you add a lot of chunks and you do find the overall brownie is too soft and doesn’t cook well, you might want to consider reducing the amount of chocolate in the batter slightly, but maybe only by 10% of the weight of the chunks.
With regards to the matcha, I haven’t tried matcha brownies (yet) but would expect you would only add a little bit of matcha. I would suggest reducing the amount of flour a little (I would start taking out half the weight of matcha in flour, so if you add 40g matcha, remove 20g flour). If it turns out too dry, you might also want to increase the butter or chocolate. Assuming you add that 40g of matcha, probably start by increasing those by 15-20g.
Hope that helps and good luck with your baking quest!
I have a question 1/2 cup + tablespoons is like 95 grams and in you recipe you say 60 grams of flour which one should I use?
I would always recommend buying a cheap scale for your baking endeavors, it makes life a lot easier and baking way more reproducible (especially if you’re using recipes, if you’ve got your own proven recipes you’ve baked for years using cups it matters less). Also, using a scale means you’re not limited to your cup sizes anymore but can get any quantity you want.
That said, I would use the following:
60g flour = 1/2 cup
150g flour = 1 + 1/4 cup
Keep in mind that cups are inherently inaccurate, your cups might be a slightly different size than mine (they’re not always standardized 🙁 ) and you and I, using the same cup might easily get a difference of 5-10g in how much flour we get with the cup depending on how we use them.
What a great piece and thank you for sharing. I LOVE Brownies and have perfected my own recipe over 10 years. Mine calls for cocoa powder as I love the rich dark chocolate flavor it gives and then add in tons of chocolate chunks! Yummy
I would like to make them a little more fudgey without having to use chocolate and also find my batter thick, so layering it with let’s say, salted caramel is difficult as the batter isn’t runny.
Thanks for your help
The main difference between cocoa powder and chocolate is the difference in sugar and fat content. Chocolate contains more sugar and more fat. If you don’t want to use chocolate but still get the effect of chocolate, consider adding some oil or melted butter to the batter, that will also loosen it up and make it easier to incorporate other ingredients.
Hi, Can I use any gluten free flour like oat, coconut or almond flour?
The flours you mentioned will behave very differently and I would expect some to result in a very crumbly, non-coherent brownie. Doesn’t mean you can’t try, but it’s quite likely you’ll have to adjust the recipe. If you want to go gluten-free I would recommend using a gluten-free flour from the store that claims to be a good replacement for wheat flour. I wouldn’t expect you to have issues with that!
Hie. If we all together want to remove eggs, what substitute we have then?
Generally, it’s best to start of with a recipe that’s designed to be made without eggs from the getgo. If you do want to remove the eggs from this recipe you might need to do a few test runs. We did some experiments with egg replacers for cake that might help you here. You could try some of the ‘egg replacers’ that are sold in some supermarkets as a first try.
Good luck 🙂
Hi! Can I ask the shelf life of this recipe? Room temperature and refrigerator life.
I wouldn’t know the exact shelf life, but you can easily keep these are room temperature for a few days (though they’re best eaten fresh, they’ll start to get a bit more stale over time, a quick re-heat can prevent that though). In the fridge I would expect you can keep them for a week or two, but use your own judgement. They’ll probably turn stale before they actually spoil but keep an eye out for moulds and yeasts after a while. There are several recipes mentioned above, the shelf life for all of them is about the same.
Hi. I have a question. What brownie brands do you recommend for the fluffiest brownie. Thank you.
Ooh, I’m not an expert on brownie brands unfortunately! Also, the brands differ a lot based on where you live (those in the US, will be different than those in Europe for instance).
If you’re making brownies yourself, I would recommend you aim for a more cakey brownie. Those tend to be a little fluffier and less dense. Also, if you don’t like a gooey, soft inside, baking the brownie for just a minute or two longer can already change the texture a little.