This site uses only a few technical cookies necessary for its operation. By continuing to browse, you accept their use.
To find out more...
To find out more...
The (small) miracle of béchamel sauce
Making a béchamel sauce is going to confront you with a little miracle that happens every time: You pour milk over a roux, it's very liquid, you stir over a low heat, and then all of a sudden, miracle, the sauce sets, it thickens, you've got your béchamel.
Let's see what happened.
Let's see what happened.
8,592 4/5 (4 reviews)
Keywords for this post:SauceMethodPrincipleExplanationStarchTemperatureRouxConsistencyBéchamelLast modified on: August 27th 2024
The (small) miracle of béchamel sauce
A basic sauce
Making it is quite simple: first a "roux" mixture of flour and butter, which is heated and colored (hence its name).
Once the roux has reached the right color, cold milk is added, the mixture is very liquid, and you continue to cook and stir over low heat until it thickens (you'll find the full recipe here).
But why does it thicken? As you'd expect, there's no magic involved, just a little physics and chemistry.
Flour and starch
The secret lies in the roux's flour, which contains grains of starch, a complex sugar made up of glucose molecules rolled up into tiny little balls.
It's around 70°C that the magic happens: the grains of starch in the flour break up into smaller grains, starch molecules that begin to absorb the milk around them, up to 20 times their volume, thus increasing the sauce's viscosity.
This process, known as starch gelatinization, takes place between 70°C and 85°C, giving béchamel its characteristic thick, creamy consistency.
Note in passing that this process of starch gelatinization is also at work in, among other things, crème pâtissière or flan, where flour is often replaced by maïzena, a corn starch.
In short: Béchamel thickens because it contains flour that is heated, causing its starch grains to burst and absorb the milk around them.
So béchamel is not just a culinary classic, it's also a little chemistry lesson in action.
Lasts posts
Butter vs. grease
We often read in a recipe where a pastry is put into a mould that, just before pouring, the mould should be buttered or greased. But what's the difference between these 2 terms?December 1st 20259265
Getting out of the fridge early
Very often when you're cooking, you need to take food or preparations out of the fridge, to use them in the recipe in progress. There's nothing tricky about this: you just take them out of the fridge and use them, usually immediately, in the recipe. But is this really a good method?November 24th 20251,0715
Who's making the croissants?
When you look at a bakery from the outside, you naturally think that in the bakery, the bakers make the bread, and in the laboratory, the pastry chefs make the cakes. It's very often like that, with each of these professions having quite different ways of working, but sometimes there's also one...November 23th 2025967
Oven height
When we put a dish or cake in the oven, we naturally tend to put it on the middle shelf, and that's what we usually do. But in some cases, this position and height can be a little tricky, so let's find out why.October 8th 20252,6585
The importance of sieving
In recipes that use a fine powder (flour, powdered sugar, etc.), you'll often see the advice to sift before using it. To sift is to pass the powder in question through a sieve (a very fine strainer) before incorporating it into your recipe. It's often advice, but is it really useful?September 3rd 20257,4783
Other pages you may also like
The return of the "Norman hole"
You maybe know the "trou normand", this old gastronomic custom typically French which consists in taking a (small) glass of calvados, generally between the last course and the dessert? It's something that seems a bit anachronistic nowadays, having a glass of an alcohol of more than 60° in the...December 18th 202115 K4.8
No need to boil gelatin
Gelatin is a magical ingredient for making light, creamy, structured desserts, yet it's often misused in the kitchen. A common mistake in some recipes is the idea that it needs to be boiled for it to work properly, but this is a mistake indeed: gelatin melts at a much lower temperature, around...November 21th 20248,1995
Cleaning endives
If you buy your endives elsewhere than in supermarkets, and in this case the best is of course from a market gardener, he or she is the one who planted and harvested them, in this case you will have endives full of earth or sand, depending on where they were grown, which is normal and reassuring, we...March 24th 202026 K4.6
The return of the vegetable grater
If you are of a certain age (say +50) you may have known, when you were a kid, something that your grandmother had in her kitchen set, the vegetable grater. A kind of mill, to be turned by hand, and which with cutting discs of different sizes, allowed to grate a lot of vegetables, carrots first...March 20th 202117 K4.6
The color of the bread crumb
When you go to buy bread, at your baker's, at the time of the choice, if you hesitate of course, you will undoubtedly be very sensitive to the color of the crust, and you will be right. The color of the crust, from golden, to sometimes very dark, deep brown almost black, depending on the maturity...April 30th 202221 K4.6
Post a comment or question
Follow this page
If you are interested in this page, you can "follow" it, by entering your email address here. You will then receive a notification immediately each time the page is modified or a new comment is added. Please note that you will need to confirm this following.
Note: We'll never share your e-mail address with anyone else.
Alternatively: you can subscribe to the mailing list of cooling-ez.com , you will receive a e-mail for each new recipe published on the site.