Elsewhere on this site is an article highlighting the bakery (Red Hen Baking Company’s Baguette) and in it we cover some of the techniques used by a small wholesale bakery in rural in Vermont. They make fantastic, if not entirely traditional, organic hearth breads which they distribute across a wide swath of central Vermont. From that article:

Their production also employs some interesting techniques that, while not unique to Red Hen, are not often encountered. Red Hen uses a method called “double hydration” for the addition of the water to the mix. In this method 80% of the total water added to the mix is incorporated at the start along with the flour, poolish, levain, and yeast. The Red Hen baguette dough is quite wet - at times approaching 70% hydration. The double hydration method allows them to efficiently develop the gluten in this wet environment without over mixing. The remaining water is added later in the mix, after most of the development has taken place.

In this article we will take a brief look at the topic of double hydration.

Water is such an important in the overall baking process, but for most bakers, it seems, their interest in water doesn’t extend too far beyond adding it in the appropriate amounts to achieve the dough consistency they desire. But the underlying physics of water in a dough is quite complex. From Pyler(1988):

When water and flour are mixed together, dough results. The consistency or mobility of the dough is directly related to its water content. Acceptable dough mobility is obtained only after the water content has exceeded the limit required for the hydration of the flour components, a limit that varies somewhat with individual flours, and below which the water may be regarded as occurring in the form of “bound” water. Bound water represents moisture that is so tightly adsorbed by the flour particles and constituents as to be unavailable for solvent action or as a lubricant.

Whether you are a homebaker or a professional baker you have witnessed this phenomenon of bound vs unbound or “free” water. When you first place the flour and the water in the mixer bowl and begin to mix the mixture is not much more than a slurry sloshing around. Early on most of the water is unbound and simply allows the flour particles to slide past one another. As mixing continues the water adsorbs to the flour particles (the starch granules, pentosans, etc) and the dough stiffens. At some point, the flour has adsorbed all the water it is capable of and any excess water remains unbound and contributes to rheological properties of a well made dough: extensibility in proper proportion to elasticity.

Returning to our subject of double hydration and looking at it in the context of bound and free water it makes a fair amount of sense in terms of highly hydrated doughs. By adding only 80% of the water needed for the dough you are ensuring that you have just about met the threshold of the flour’s bound water limit (ie you have a very stiff dough). In the absence of much free water there is not much lubricating action within the dough and the gluten forming proteins can be rapidly developed (without sliding past one another in an inefficient manner). Once the dough is developed you can then add the remaining water and incorporate during the final minute or two of the mix.

Here is the formula for the Red Hen Baking Co baguette (if you want to see how to make it go to the article referenced above).

Red Hen Baking Co.’s Baguette

Poolish

Bread Flour

Water

Yeast

Yield

12.1 kg

12.1 kg

0.01 kg

24.2 kg

100%

100%

0.05%

Levain

Chef

Bread Flour w/ Germ

Water

Yield

0.7 kg

1.5 kg

1.8 kg

4.1 kg

40%

100%

120%

Final Dough

Bread Flour

Water

Poolish

Levain

Yeast

Salt

Yield

26.2 kg

14.1 kg

24.2 kg

4.0 kg

0.1 kg

0.8 kg

69.4 kg

11.1%

88.9%

71.8%

0.5%

3.5%

63.2%

38.9%

Overall Formula

Bread Flour

Bread Flour w/ Germ

Water

Poolish

Levain

Yeast

Salt

38.3 kg

1.8 kg

28.4 kg

24.2 kg

4.0 kg

0.1 kg

0.8 kg

95.4%

4.6%

70.8%

60.0%

10.0%

0.2%

2.0%

So if you were to make this formula using the double hydration method you might proceed like this: Add your total flour, poolish, levain to the mixer along with about 8.8kgs of water. How did we come up with that amount? You can see from the formula that the poolish contributes 12.1kgs of water and the levain contributes 1.8kgs of water. Your total formula water is 28.4kgs. 80% of 28.4 kgs is 22.72kgs. From the poolish and levain you get 13.9kgs with the difference being 8.8kgs. At Red Hen they mix this dough for a 1-2 minutes to incorporate into a shaggy mass, give it a 20min autolyse, and then mix almost to full development. At this point the remaining water is added along with the salt and yeast and mixed to incorporate. (They mix this final stage on reverse which is an interesting. Some bakers have said this would server to “unwind” the developed gluten structure. That probably isn’t quite the case. Perhaps the thinking is that reverse doesn’t develop the dough as much but does a really good job of rapidly incorporating the water into the almost finished dough.)

Using this method you should be able to achieve proper mixing of high-hydration doughs without overmixing. That’s the theory anyways.