1,538 easy and fully explained recipes, with +66K photos and 78 videos

This site uses only a few technical cookies necessary for its operation. By continuing to browse, you accept their use.
To find out more...

Raising (or leavening) agents

When we want to make a dough or batter rise when baking, either in patisserie or bread-making, we need to use a raising agent or leavening agent, one of which is called leaven.

In the context of baking, a raising agent is simply what "makes something rise". It is a substance which, when added to the dough or batter makes it swell up by creating thousands of tiny bubbles of carbon dioxide within it.

As there are 2 kinds of yeast, 2 kinds of leaven and baking powder as well, this can be confusing, so here is a summary of the different types and how they act.

57 K 4.8/5 (18 reviews)

Keywords for this post:Yeast Sourdough Bread Bakery Pastry Baking powder

Last modified on: June 16^th 2021

For this post: Comment Follow Ask me a question Send to a friend

Raising (or leavening) agents

Baker's Yeast

This is the yeast used by bakers to make bread, brioches, etc. It is basically the same kind that brewers use to make beer, so it is sometimes also known as brewer's yeast.

Yeast is a living organism, a microscopic fungus, called saccaromycès cerevisae, which reacts with the sugars in flour to form carbon dioxide. It is this fermentation process that makes the dough rise. Yeast is available in 2 forms:

Fresh yeast

baker's yeast

This is the classic baker's yeast which is normally sold as a small, beige-coloured block. It should be kept in the fridge and not for too long.

Dried yeast

dried yeast

This is exactly the same yeast, but completely dehydrated. It comes as a beige powder and keeps very well.

Baking powder

baking powder

This white powder is a mixture of bicarbonate of soda and cream of tartar. It reacts on contact with the water in the dough or batter to form the carbon dioxide which makes it rise. There is no fermentation.

Baking powder is used mostly for cakes, scones, etc.

Leaven

Leaven is a natural raising agent, like yeast. It is made from a mixture of water and flour that begins to ferment when exposed to the naturel yeasts present in the air.
It is a living substance and reacts with the sugars in flour to form carbon dioxide by fermentation, which makes the dough rise. Two different forms can be made:

Liquid leaven

liquid leaven

This is a leaven made with equal parts of water and flour. As the name suggests, it is liquid, rather like pancake batter.

Stiff leaven

stiff leaven

This is a leaven made with one part water to two parts flour. It has a consistency similar to bread dough.

Whether the leaven is liquid or stiff it makes little difference in its use, but a lot in the taste of the bread obtained.

It is worth noting in passing that when making leavened bread, it is usual to combine a large amount of leaven with a little yeast. This improves the bread's appearance especially the crust.

Summary

We can say that yeast and leaven work by fermentation, whereas baking powder uses a chemical reaction.

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 1^st 20258205

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 24^th 20251,0235

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 23^th 2025920

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 8^th 20252,5495

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 3^rd 20257,4123

See all posts Random post RSS feeds

Other pages you may also like

The bitterness of endives

As I write these lines, we are entering the endive season, and if you like it, it's time to enjoy it, if possible with your local producers. Endive is good, but the reproach that is often made of it, and children in particular, is: "It's bitter! And it is (somewhat) true of course, endives...
February 9^th 201914 K4.9

Different kinds of pastry and dough

When cooking in general, and particularly in baking, we can make and use many different kinds of pastry and dough. All built on the same "base": flour - a powder to which we add fat, liquid or both to produce the dough which is then cooked. .
November 6^th 2012111 K 14.0

Candied fruits: don't get ripped off

Do you like candied fruit? You might like to nibble a handful or add it to a recipe, like a classic fruit cake or delicious Italian specialities like panettone or sicilian epiphany pie.
June 21^th 201767 K 24.2

How to break eggs properly?

It is a very common gesture in pastry, bakery and of course cooking: breaking eggs to incorporate them into a recipe. You have eggs (which professionals call "shell eggs" to differentiate them from liquid eggs in cartons or cans), and you must break them to incorporate the contents into your...
June 26^th 202115 K4.8

Don't throw away disposable piping bags

Nowadays, it's fairly easy to find what professionals use as piping bags, i.e. disposable or "single-use" plastic ones. They're practical, functional and inexpensive, but disposable? That's debatable...
May 28^th 20248,9905