How to choose your flour: understanding protein strength & elasticity. A little guide.

April 25, 2020

How to choose your flour: protein strength & elasticity. A little guide.

It seems the perfect time to shine a little light on what seems to be an increasingly popular product: flour.

As you may have noticed, all the flours in our shop report some "values", such as protein content, W and P/L. This article tries to explain the different indicators, and how to choose the right flour for what you need. 

FLOUR CATEGORIES

First thing first: flour is categorised in different types based on the degree of sifting, obtained by sieving the ground and separating the noble part of the wheat from the bran. Type 00 (soft), type 0 (plain), type 1 (strong), type 2 (hard), and wholemeal flours, in this order, progressively contain a greater quantity of bran; therefore the 00 is the most refined, while the 2 is the closest to the whole wheat which instead contains all the parts of the grain.

The type 00 and 0, as well as being the finest and whitest, are made with the innermost part of the grain, richer in starch but low in fibres, protein, vitamins, fats and enzymes. They however favour the reproduction of yeasts and the development of gluten.

PROTEIN

Gluten is a combination of the natural proteins found in wheat, specifically in the endosperm of the grain. When flour is moistened, either kneaded or mixed, the gluten molecules activate. When this happens, the gluten literally stretches out as the proteins form longer and longer chains. This is what give the elasticity to your dough, allowing you to stretch it. 

These strings then encapsulate the gases produced by yeast or another leavening agent, causing the dough to rise. When you cook the proteins, these will harden, keeping your preparation in place. 

As a rule of thumb, the higher the protein content, the more strings you can produce, the more kneading your dough can sustain. 

STRENGTH

Until recently, commercial flours didn't have the W content written on the label, but with more and more connoisseurs and home pizza makers, we are starting to see a shift with technical information once only reserved to professionals, now provided on the packaging. 

But what is the strength of the flour and why is it important? Well, basically the strength represents the ability of the dough to withhold gas and absorb water. To test it, they literally blow the dough up to see how much gas it can take!

While strength may not be a relevant factor when you bake cookies, it is very important if you make pizza, or croissants, where long leavening time and hydration become important to the end result.

In short: a higher W content means a greater ability to support mechanical stress, manual kneading, long leavening times (the dough rises and stretches) but also the ability to absorb and withhold water. More on this after the table.  

RESISTANCE/ELASTICITY

The resistance (P) is the force necessary to lengthen the dough while the elasticity (L) is the ability to stretch without breaking. An optimal flour should have a P/L ratio of about 0.55. Lower values indicate a flour that will generate a fragile and slightly extensible dough, while higher values represent a flour that will generate a very tenacious and hard dough (difficult to stretch). If you need an example, Durum Wheat has a very high P/L ratio and it is one of the hardest dough to stretch, rarely used to make bread. 

 W Strength  P/L Protein %  Perfect for 
 up to 170   0.4 - 0.6   10/11 They have an absorption capacity equal
to about 50% of their weight in water.
They are ideal for small pastries,
biscuits, breadsticks.
 180-260   0.45 - 0.5  10.5/12

They are suitable for leavened dough 
that require an average quantity of water
(or other liquids) such as French bread,
oil or some types of pizza.
Short leavening at room temperature. 
They absorb about 55% -65% of their
weight in water. 

 280-350   0.55   13 These are flours used in leavened dough 
that require a high amount of water
(or other liquids) such as bread, brioches,
pizza. Also great for preparation 
requiring double leavening, whether
ambient or in the fridge.
They absorb about 65%-75% of their
weight in water. 
 Above 350   0.55 - 0.6   13.5/15 These are flours produced with special
grains, especially American and Canadian,
such as Manitoba. They are used to
reinforce weaker flours or to produce
particular breads, or long leavening
preparations such as Panettone,
pandoro, hamburger buns.
It requires high hydration as they absorb
up to 90% of their weight in water.

 

HYDRATION (MORE ON STRENGTH)

Why is hydration important? Yeast is only the starting point of the leavening process, but when you put your dough in the oven, after 45-55°C it stops being active. So how can the dough still rise, if the yeast is no longer contributing?

By that time, all the air pockets in your dough will start expanding, which means that the more your dough is hydrated, the larger these air pockets will become when water starts evaporating at 100°C. 

In short, higher hydration leads to larger bubbles, which leads to a lighter bread. 

This is a super simplistic way to explain, but I hope it is visual enough to make sense and for you to remember what happens and why you need one product or another.

So a question you might have is: can I use a less strong flour with a lower protein content to bake pizza? Yes, to a degree, you can. However, with less hydration you will have a heavier dough, and the result of your hard work may not be as good as you hoped.

I could go on and on about maturation, and other tricks I have seen the professionals discuss, but it may be a little overwhelming all in one place.

Truth is, the world of bread makers and pizza lovers is an incredibly complex one, and if you like me, are increasingly becoming curious and intrigued by how flour can create something completely different starting from the same ingredients, then feel free to say hello.

We'll share recipes and tips on how to make the best pizza. We might even attempt a home panettone challenge next Christmas!