You can make a great cookie with sugar, butter and flour (that is, shortbread), you can make a delicate crispy almond tuile by adding some egg and almonds. But, your tuile (and a lot of other cookies as well!) become so much more better by adding just one extra step to your cookie recipe: browning your butter.
Often there is no need to add complicated flavours or expensive ingredients to your food. Just let your current ingredients shine and give them a little hand in doing so, to create a richer flavor profile.
What is brown butter?
Brown butter is in itself a very good description of what it is: it is brown butter. You get brown butter by heating your butter (without burning it!) gently until it hard turned a light brown in colour. Brown butter smells delicious, nutty and caramelly and is far richer in flavour than just butter itself. Your whole kitchen will smell amazing when making it.
Why does butter brown?
So why does butter even brown? For that, we have to look at the composition of butter. Butter consists of about 80% fat (butter fat) with the rest being mostly water. There is a small percentage of proteins and sugars (lactose).
You create brown butter by gently and slowly heating it up, until it has literally turned brown (the recipe at the end of this article gives a more extensive explanation). While doing so, your butter will initially just ‘boil’. You will see air bubbles within the butter and moisture evaporating. As long as moisture evaporates, the butter won’t get really hot, the evaporating water keeps it cooler. As a result, during this time you will not see a great change in colour of the butter. You use this same process when making ghee (or clarified butter) as well.
Once the majority of that moisture has evaporated, you’re left with mostly fats. These fats can heat up to a far higher temperature than the fat + water mixture can. It can go up to temperatures suitable for frying (e.g. 180C or 350F) and won’t be as bubbly at this point anymore. It will only get so hot if the butter is completely clarified of those remaining sugars & proteins. If not, the butter will turn brown and burn. When making brown butter you do want this browning to occur, which is why you can’t make browned butter from clarified butter (or ghee)!
It is during this phase that the browning of the butter happens. The sugar and proteins and to some extent the fats, undergo a wide variety of chemical reactions that lead to delicious flavours, smells and colour.
The reason the butter turns brown is the Maillard reaction. The Maillard reaction is a well known chemical reaction that occurs in foods that contain proteins and reducing sugars (e.g. lactose) when they’re warmed up sufficiently. Once your butterfat is warm enough and the moisture content is just right, the proteins and sugars in your butter start to react. This is when all those delicious nutty flavours start to develop!
The Maillard reaction in reality is a whole range of reactions occurring simultaneously. Brown molecules as well as very flavourful molecules are formed along the way (we discuss the science in more depth here).
Flavour of butter is a feast of molecules
Even before you’re browning your butter, that butter is already full of flavour molecules. During storage, some of the fats in the butter will oxidize. Whereas extended oxidation of fats will turn butter rancid, some oxidation generally improves and enriches the flavour of butter.
But the fatty acids in the fats in butter can take part in several other chemical reactions as well such as lipolysis. These reactions speed up when you heat your butter. As such, while your browning your butter, it is not just the sugars & proteins that react. Instead, the fatty acids are reacting as well to some extent.
An important type of molecule that is formed during these reactions are lactones. Lactones are a group of molecules with a similar central structure. They again have strong characteristic flavours.
Overall, the flavour of butter and especially browned butter is highly complex. A lot of different molecules are present that each add a bit of themselves to the mixture of flavours in the butter. It can enrich the flavour of all sorts of foods tremendously, such as these almond tuile cookies below.
- 75 butter
- 100g sliced almonds (can be either with or without the brown skin on, we used with skin on)
- 100g granulated (regular) sugar
- 60g all purpose flour
- 135g egg white (from 3-4 eggs)
Making brown butter
- Weigh the butter and place it in a small sauce pan. Place the pan over low/medium heat.
- The butter will melt initiall. You can swirl the pan or use a spatula to move the butter around to speed up the melting. After this is it easiest not to touch the pan at all, there is no need really to stir. If the butter start sputtering, turn down the heat.
- Once the butter is melted you will want it to boil gently. During this process the remaining moisture in the butter evaporates. Once the moisture has evaporated the butter might not look as warm anymore, but actually this is the point things start moving quickly! You will notice that on the bottum of the pan particles start to form which will turn brown (and if heated too quickly black!). Continue to heat until they are a dark brown. The butter will smell very nutty and be full of flavour! Turn off the heat once the butter has browned. If you accidentally burn it just slightly, don't worry, it adds a bit of extra flavour!
- Pour the butter through a fine mesh (or cheese cloth) to sieve out the dark particles and leave the butter to cool down to the touch so it doesn't cook your eggs in the next step.
Making the cookies
- Mix the sliced almonds, sugar and flour in a bowl. (Pre-mixing helps prevent clumps of flour from forming in your batter in the next step since the flour particles are surrounded by sugar.)
- Fold the butter through the mixture.
- Add in the egg whites (no yolks!*). The mixture will not be smooth and quite lumpy with all the almonds, that is ok.
- Add little spoonfuls of batter on a baking tray covered with parchment paper or silicone mats. Ensure that the cookie batter is spread out completely flat, you don't want any almonds lying on top of one another. The cookie will not spread during baking, so the size you spread it out here will be the final seize. They'll be only 1-3mm thick!
- Bake the cookies in a pre-heated oven at 180°C (350°F) for about 15-18 minutes. Watch the tuiled like a hawk towards the end, once they start turning brown, they are prone to burning. You don't want to burn the cookies here, instead, making them a medium brown colour (like bread). Every oven will behave slightly different.
- The cookies are flexible when just out of the oven, so you can curl them up. If you don't want to curl them, keep them flat on the tray for a few minutes so they remain straight. Once they're firm, remove the cookies to a cooling rack or plate to cool further.
*Use the yolks for making ice cream!
Dufossé, Laurent & Latrasse, A. & Spinnler, Henry-Eric. (1994). Importance of Lactones in Food Flavors – Structure, Distribution, Sensory Properties and Biosynthesis. Sciences Des Aliments. 14. 17-50. link
Patrick Fox, Advanced Dairy Chemistry volume 3: Lactose, water, salts and vitamins, 2nd edition, p.420, link
Gerda Urbach, Butter flavour in food systems, Food Research Quarterly Volume 51, 1991, link