1,504 easy and fully explained recipes, with +66K photos and 78 videos

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.

54 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 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

Always secure your cutting board

When using a cutting board, it's very important that it's stable and doesn't move while you're cutting, for safety's sake. Boards have a natural tendency to slide on the work surface, but here are 2 ways to block them effectively.
July 1^st 20255505

Cherry clafoutis, with or without pits?

When it comes to cherry clafoutis recipes, there's often a camp of those who argue that you absolutely have to leave the stones in because it tastes better, and the other camp (myself included) who prefer cherries without stones, which makes a much more pleasant clafoutis to eat. But is it true...
June 29^th 20256885

Should potatoes be washed twice?

Let's say you have to make a recipe that includes potatoes, let's say sliced, you'll most likely proceed as follows: Peel the potatoes, wash them, slice them, wash them again, pat them dry and add them to your recipe. But there's a "but": depending on the recipe, the second washing may be a bad...
May 19^th 20252,297 15

Grilled bacon is much better in the oven

Some recipes call for thin slices of bacon to be cooked and added to the recipe, or to prepare one of those delicious breakfasts known as "à l'Anglaise".
April 25^th 20252,0575

The thermometer is your friend

There are many recipes or foods that require a (very) precise cooking temperature: foie gras, sugar for caramel, meats and fish, and not forgetting pastries. For these few examples, getting the cooking temperature wrong can spoil the whole recipe or dish: undercooked, it's no good or misses the...
April 10^th 20252,3775

See all posts Random post RSS feeds

Other pages you may also like

The secret of cooking until "done"

This is a real chef's skill: being able to look at a fish fillet cooking and say, "Stop – that's enough, it's cooked". I always admire this ability to see at a glance if something is done. It is what sets the professionals apart from us mere amateurs. And it's true that how fish is cooked is...
November 26^th 201218 K4.4

Making the most of seeds: Dry roasting

In cooking, and particularly in baking, there are a lot of seeds we can use, such as linseed, sesame, poppy, etc. Usually, recipes simply say to add them just as they are to the mixture or dough. To make a seeded loaf, for example, prepare a plain bread dough as usual, then, towards the end of...
January 30^th 201559 K4.0

What can I use for blind baking a pastry case?

When it comes to home-made desserts, tarts are always popular. They can be divided into two basic types: those cooked with their filling, such as an apricot and almond cream tart, and those where the filling is added after baking the pastry case, such as a strawberry tart or chocolate tart. For...
May 2^nd 2017108 K4.5

The march forward

When professionals get to work in their kitchen, lab or bakery, they are (if they are conscientious) very sensitive to hygiene and cleanliness. It is impossible for a good baker for example to do a day's work without regularly cleaning the table where he or she works, and it is even more...
June 30^th 202117 K5

Drawing a pattern in pastry

Often in the kitchen, in pastry-making, or in baking, we need to trace a pattern on a pastry. It's just a question of aesthetics but it has its effect after baking on a galette, pithiviers, pâté en croute (terrine in a pie crust), etc.
May 23^th 201931 K4.1