The Fresh Loaf

A Community of Amateur Bakers and Artisan Bread Enthusiasts.

Two Questions - Hydration and Bulk Fermentation

slowriser's picture
slowriser

Two Questions - Hydration and Bulk Fermentation

Sorry for the long post but this has been bothering me for a while.

I tend to work better when I understand a subject and at least 2 things have been bothering me lately. 

1) How does hydration effect dough? Obviously if it is too low or too high it wont be a good bread but if its somewhere in the middle (say 55 %- 75%) what effect does it have on they dough? why are baguettes usually 70-75% hydration and Neopolitain pizzas are 58%? Is it just because of the oven and temp they are normally baked in - so neopolitain pizza is in a 900 degree oven so it needs much less water and a baguette is in a 450 degree oven so its much more? I know that close to neoplolitain style pizza can be made with higher hydration in a lower temp over does the same hold true for a baguette can I lower the hydration and the temp i cook it at and come out with similar results? I guess I am just generally confused about the hydration percentages roll in baking.

 

2) what is the point of the bulk fermentation? If i was making rolls or pitas is there any reason why I can't split them in to the correct size portions immediately and let them ferment individually? 

mariana's picture
mariana

Hi slowriser!

1) it is not so much hydration as dough consistency that matters. Some goodies require soft dough, others - stiff dough. It affects everything, how it ferments, how fluffy it gets, how it bakes and how it tastes when you bite and chew it.

Baguette dough is usually baked until it loses anywhere from 25% to 50% of its original weight, a lot of water is lost as it bakes, water evaporates, so it is a bit moister originally. Pizzas are usually baked quickly and have moist toppings so the dough stays moist and doesn't lose as much water as it bakes, therefore it doesn't need as much water initially inside it.

2) the point of bulk fermentation is fermentation. In other words, it makes freshly mixed dough into a mature, ripe, ready to use dough that is tasty and fragrant and could be used in the kitchen or in a bakery for any other purpose: to sell it as 'bread dough' or 'pizza dough' to the customers, to fry it, to steam it, to boil it, to bake it and then to serve it and to eat it. 

If you make rolls or pitas you can mix 100 portions of dough, each from 30 g of flour and 20g of water and let them 100 portions ferment until ready to be used and use each to prepare one roll or one pita. As you wish. It doesn't matter. Or you can mix 3000g of flour and 2000g of water into dough and let it ferment until ripe and mature, fragrant and tastes delicious and divide it into 100 portions and bake them into pitas or rolls. As you wish. 

If you look how bread machine works, for example, it mixes enough dough exactly for one loaf of bread or for one roll or one pita and once dough is ready, well fermented, it shapes it into a ball and gives you a signal. After that you can continue with the bread machine program and let it bake it into a loaf or take it out and do with it whatever you want at home: freeze it, refrigerate it for future use as needed, or bake it, fry it, etc. into whatever you want right away. 

best wishes, 

m. 

Benito's picture
Benito

As always Mariana’s answer is comprehensive!  I’ll just add with baguettes you need a dough that is extensible enough to elongate to the final shape but not too wet to make the shaping too difficult.  If the hydration is too low, then the dough will be harder to extend to the wanted length.  If it is too wet, it might be more challenging to deal with during shaping.

Benny

yozzause's picture
yozzause

 And to add to Benny's comment a dough that is going to be used for breads like Challah were you want to have some boldness and strong definition rather than merging into its self then a tighter mix is required.

The other point on bulk fermentation is that you can do away with it as is the case in large bread factories churning out Wonder breads this i achieved with the addition of chemical bread improvers and high speed mixers beating the dough into submission along with it soul and natural good taste which conversely is gently  coaxed out with longer bulk ferments and the gentle stretch of gluten strands  that occurs over the longer ferments. i also believe that the slow build up of gas  that provides that gentle stretch also conditions the dough  for its final shaping. the knocking back of the bulk fermented dough also redistributes the available food for the greatly increased natural population of yeast cells that has occurred during that period of time. 

Dan_In_Sydney's picture
Dan_In_Sydney

If I can add to these already great answers, there is also the mechanical actions and physical shape of the dough to consider, as well as the composition and dispersion of ingresient.

The mechanical and practical side

As your dough ferments, two competing forces are at play. The fermentation lowers the pH of the dough which works to strengthen the gluten network. However, the various enzymes are also hard at work weakening the dough. The positive of this action is that it generates extensibility, however you will notice that, as you leave a mass of dough to ferment - whether in bulk or divided - the dough will tend to spread out and 'relax'. This spreading increases as time goes on, thus, the longer a dough is fermenting, the more it is spreading.

As a purely practical matter, dividing your dough early means you have multiple masses of dough, each spreading and thus each requiring its own dedicated space to relax and ferment. This is annoying enough in a home setting; it would be at best unweildy in a commercial bakery but likely nearly impossible to manage and uneccesarily increase the work required.

At the simplest level, the least inefficient way to do this would be to have the individually-portioned doughs fermenting directly on a bench, covered. If you are a home baker, whipping up a half-dozen dinner rolls for the family, that's fairly do-able but, again, in a commercial setting - where you are making an order of magnitude more rolls - it's just not feasible.

Now, ff you're making two loaves, that's fine and might even be a good thing, as you can put one batch in the fridge sooner or experiment with different add-ins of processes. For pita or rolls, I am going to assume at least 4 and likely 6 or more and, further, that you are likely after uniform results throughout, so the potential benefits of individual fermentation is likely not there for that situation, even if the negatives are manageable.

Once they've fermented, you then need to shape the dough pieces - most usually with an initial pre-shape and then a final shaping, where the nearly-ready dough pieces are placed in their final proofing forms.

Let's say you're making a dozen small dinner rolls with commercial yeast with a quick process (~3 hours' fermentation).

When performing a standard bulk-ferment, it all goes in one container and is tucked away for a few hours. Once, say, 2 hours is up, it's tipped out in one mass, scaled into 12 pieces and each piece is pre-shaped and left for 30 mins on the bench.

After 30 mins, those balls will have spread out a little and so they undergo another, final shaping and are placed in their proofing forms - whether thats a tray or pan or couche or banneton to whatever. This final shaping will put a tight skin on the dough that, in combination with the proofing form, will encourage the dough to rise in the desired direction (usually up!).

This series of relaxations that occur after each step is one good reason why it just causes extra pain to divide the dough at the start and ferment each portion individually.

Now, all this assumes that you are fully- developing your dough from at the start (e.g. in a mixer). If you are planning on performing any strengthening steps while the ferment is in process - most typically in the form of 'folds', if you have already divided your dough, thats multiplying your work for no real benefit. A bulk ferment allows you to perform one set of folds on one mass of dough.

The dispersion of ingredients.

To wrap this up quickly (as I am really getting tired,) when you mix your dough, you start with a very small amount of yeast that is hopefully dispersed evenly. During the fermentation, this small amount of yeast reproduces and multiples through the dough.

If you mix your portions one-by one, you can be sure there is the same quantity of yeast in each portion; if you mix it as one and then divide straight away, there is a much higher liklihood that the portions will contain different quantities of yeast, which may affect fermentation time, giving inconsistent results.

d.

yozzause's picture
yozzause

And just to add to Dans great response is the effect of temperature loss or gain with smaller portions of dough compared with a greater mass.