Brioche bread – Science of enriched breads

When you’re looking for a super soft bread, look no further: a brioche style bread is what you’re looking for! A brioche bread has a soft, fluffy structure and slightly sweet flavour. It fits well with brunches and has the great advantage that it tends to keep a little longer than a regular plain bread! Also, I’ve seen it used very often for making French toast (I personally would only use brioche for French toast once it has gone stale, it’s great just by itself!). The reason for brioche being super soft is mostly due to its ingredients, in other words, time to discuss ingredient science.

What is special about a brioche bread?

A brioche bread is a very ‘rich’ bread. Whereas standard breads can be made from nothing more than water, flour, salt and yeast, a brioche will contain plenty eggs, milk and butter. That makes a bread ‘rich’. The high fat and protein contents of these ingredients is what makes the bread so special.

A brioche used to be a bread for the rich, or at least those who had access to butter. Before the era of refrigeration that wasn’t very common. Butter would go rancid a lot more quickly and was more of a privilege, the poor would eat bread made from just water and flour, without the more expensive ingredients.

So why do butter and milk make a brioche so special?

The role of butter in brioche

Brioche contains a high amount of butter (the recipe at the bottom of this post contains 150g of butter per 500g of flour, but there’s certainly recipes with even more!). Butter consists of approximately 80% fats, the remaining is mostly water and some proteins.

Butter basics

Different fats, have different melting points (think olive oil vs. butter vs. coconut oil). Most of the fats in butter are solid in the fridge. However, at room temperature part of the fat will melt. That results in a softer butter (and is something we try to prevent from happening in short crust pastry). When heating the butter a little more (approx. 40C) the butter will be liquid and almost all fats will have molten.

Role of butter in brioche

So why do we want these fats in a brioche bread?

The main reason is sensory: fat in products makes them ‘richer’ and gives them a different mouthfeel, it becomes more smooth. Besides this general role, in brioche butter has a slightly more specific role. When a brioche dough (which contains the butter) is placed in a hot oven the butter will melt. As a result the fats become a bit more mobile and they will re-organize themselves slightly. Since fats don’t tend to like to sit in water, it has been found that the fat will actually surround the air bubbles in bread. This way the fat stabilizes the air bubbles. As a result, brioche breads tend to have a lot of small air bubbles.

At the same time fat lubricates the dough. It will help the flour particles move alongside each other more smoothly. That makes doughs with a lot of fat very flexible and stretchable. The fatty lubrication helps expansion of the dough.

Since the fats remain in place after baking (they cool down and solidify again), they will remain around these air bubbles. That helps in keeping the bread fresh, it serves as a protective layer.

Using butter in brioche

For a brioche bread we don’t tend to melt the butter when using it in the dough. We do soften it (to help with kneading), but melting it would make the dough too soft and sticky.

Also, butter shouldn’t be added at the start. Reason being that butter (or more specifically fats) interfer with the formation of a gluten network. This gluten network is of importance for creating a strong, springy consistency of the bread (as we’ve described in a separate post dedicated on gluten). The fat in butter will cover the gluten proteins, preventing them from doing their job in making a strong dough.

Therefore, butter in a brioche dough is ended towards the end of the kneading process. At that point in time the gluten network should have been able to form. The butter will still coat the gluten particles creating fat bubbles in the dough. These will then melt when the bread is baked.

The role of eggs in brioche

Eggs have several roles in a brioche bread. One of the roles is very similar to that of butter. Egg yolks contain a lot of fat and this has a similar role to that of the fats in the butter.

The eggs however contain a lot more water than butter does, so it also contributes significantly to the moisture content. This is why the eggs are added during the kneading process, else there wouldn’t be enough moisture.

Besides fats and moisture the eggs also contain a lot of proteins. These proteins will set when baking and will influence the texture of bread, however, the influence should be pretty minor. They have a bigger impact actually on the colour of the bread. Since these proteins can participate in the Maillard reaction which is a browning reaction between sugars and proteins. The more proteins in a bread dough, the faster it becomes brown. Since a brioche dough also contains quite a bit of sugar, they tend to brown very quickly.

The role of milk in brioche

 

Last but not least a brioche dough contains milk instead of water. Milk again plays several roles. It contains proteins which contribute to browning and (unless you’re using skimmed milk) it contains fats. The roles they play are again pretty similar as to those of eggs. Milk enriches a bread, makes it a little softer, affects that flavour and changes the overall appeal of the product.

A brioche bread has that fluffy rich texture and taste. We discuss the science of brioche breads, what makes it so special? | foodcrumbles.com

Brioche recipe

Below you can find a recipe for such a Brioche style bread. It is inspire by a recipe from Paul Hollywood. Notice the high eggs, butter and milk content!

Brioche bread - Science of enriched breads
 
Prep time
Cook time
Total time
 
Author:
Serves: 1 large brioche bun
Ingredients
  • 500g flour
  • ¼ tsp salt
  • 50g sugar
  • 1 tsp yeast
  • 3 eggs
  • 240ml milk
  • 150g butter
Instructions
  1. Mix the flour, salt, sugar and yeast by hand.
  2. Add the eggs and milk and use a stand mixer to create a smooth dough (or knead by hand). The dough should be moist, but shouldn't stick to the sides of the bowl anymore.
  3. Once a good dough has formed, add the butter (best at room temperature and cut in small pieces) to the dough. Leave the stand mixer to mix in the butter, this will take several minutes.
  4. The dough will become very sticky at this point.
  5. Cover the dough with plastic or a lid and leave to rise for at least 1-1,5h, but feel free to leave it for 3-4 hours. It will not increase in volume that much
  6. Once proved, knead it through again and shape it into the shape your prefer. I used a cake tin.
  7. Leave to rise for at least another half an hour.
  8. Bake in a pre-heated oven at 210C for 55 min. The brioche will brown very quickly, so you might want to cover the brioche after approx. 15 min with aluminium foil. It's best not to do this at the start since the bread will still expand quite a bit.

Sources

Scientific article on the role of lipids in bread making, Journal of Ceral Science, nov. 2011

Extensive scientific article on bread and bread doughs, also discusses the role of fats.

Read our other basics article on the role of ingredients in breads in general (not geared towards brioche),

Leave a Reply

Your email address will not be published. Required fields are marked *