The myth of double in size +tips!

1. (adj.) double
twice as large, heavy, strong, etc.; twofold in size, amount, number, extent, etc.

In lots of bread baking recipes you will encounter a line like this; ‘Let shaped dough rise until it has doubled in size’. The scientist in me always wonders what the recipe writer means. Does the writer of the recipe realize that a round shape, for instance the shape of a boule, increases 8 times! in volume when the boule doubles in diameter. What does ‘double’ (or even ‘almost’ double!) mean in the context of a piece of dough in whatever shape? Twice the diameter? Twice the volume? Twice something?

And what about the word ‘size’, size is not a measurement of anything, size can mean volume, height, weight, etc. all depending on the context. So what does ‘size’ mean in the context of a piece of dough? According to a dictionary ‘double’ means ‘twice the size’, so double in size means; twice in size size. What I do know is that the line ‘rise until it has almost doubled in size’ reads like sheer laziness of the recipe writer!

1. (n.) size
the spatial dimensions, proportions, magnitude, or extent of anything:
the size of a farm.

Imagine a measurement cylinder filled with a piece of dough. When you let the yeast do its job this little piece of dough will grow inside the cylinder. As for the dough the only way is up it will slowly fill the cylinder and it is really simple to see when the dough has doubled in volume. It will be when you read twice the number on the measurement cylinder than when you started! What has doubled in this experiment is the volume.

Now imagine a piece of dough shaped in a boule. And again we let the yeast do its job and the dough will grow and grow and grow. When will this piece of dough be ‘doubled in size’? With the cylinder it was very easy to see when the volume has doubled but with this round ball shape it is much harder to see when the volume has increased twice. With a batard shape it is even harder to imagine the real mathematical or geometrical truth.

Another mind game. Take a nice lime (the fruit) and imagine it to grow. When will the lime be ‘doubled in size’? When it is the size of a mandarin, an orange, a grapefruit or a watermelon? It is hard to visualize when a round fruit is ‘doubled in size’ in comparison to another fruit.

If we simplify the shape of a dough boule to the geometrical shape of a halved sphere (Wikipedia Sphere) we can calculate the volume of the boule; the formula to calculate the volume of a halved sphere reads;

volume = 2/3 * pi * radius³ ≈ 0.667 * 3.141 * radius * radius * radius

With this we can do some calculations.

When you measure the height of the boule of dough you can use this height with the formula above as the height is mathematically the same as the radius because we have a halved sphere. For my calculations I start with an imaginary boule of dough with a height of 10cm. This gives us a boule of dough with the volume of 2093cm³ which is a little over 2 liters of dough. When you take a boule with a height of 20cm this equals about 16745cm³ which is about 16 liters of dough! So a doubling in diameter equals 8 times the growth in actual volume.

The funny thing is you only need an increase of 2.5cm in height to get a doubling of the volume of boule of dough. A height of 12.5cm gives about 4088cm³ of volume which is about 4 liters of dough. The increase of 2.5cm is hard to notice and you will not perceive this as the dough having ‘doubled in size’.

After this whole rant I still do not have the answer to what recipes writers mean with ‘wait until double in size’. Do they mean double in volume, double in height, they probably mean something like ‘wait until the dough has increased until you think it is enough’.

So, what’s the answer?

The important thing during the final proof is to stop before the gluten network collapses. When the gluten can not hold the amount of carbon dioxide produced by the yeast, the little gluten balloons explode and your bread will deflate before your eyes. The first thing is to control your dough temperature. As the temperature has the biggest influence on dough rising speeds, controlling temperature gives you stable proofing times. Please read; A Few Tips on Dough Temperature. Because I stabilize my dough temperature, my proofing times are more or less the same each time and this takes the guessing out of proofing- and bulk fermentation times.

The next tip is to use the finger poking test;

With your finger gently poke in your dough. If you have a high hydration dough you can first dip your finger in a little bit of flour to prevent sticking.

• If the hole disappears completely: under-proofed
• If the hole dent pops half way back out: proofing is just right
• If the hole stays entirely dented in: over-proofed

It is hard to explain the difference completely. The best way is to learn from experience. Poke as many proofing loaves as possible, and you will figure out what you are looking for. If you apply the finger poke test immediately after shaping, sometimes the hole stays dented, just as it would if the loaf were over-proofed. You can tell the difference by feel, because when proofed the loaf is light, “bubbly” and elastic, whereas right after shaping the loaf is not elastic.

So, proof, poke and bake as much as you can!

Invitation
What is your opinion on double in size? What is your favorite way of testing if your dough is ready for the next phase?
We would love to hear from you and learn from your experience. Please leave a comment.

Ed