Liquid sourdough

One of the most used and easiest pre-ferment for breads. Basically a rough mix of water and flour in the same quantity (1:1) inoculated by a starter and let ripen over time.
Altough other percentages of water in relation of flour can be used, (sometimes raising water quantity around 200%), the most practical is 100%. Due to the high hydration, the acidity built by fermentation is more on the lactic side.
Here you have a few examples of liquid sourdough build:

Ratio:                                         Baker's math:

1 part water                               100%
1 part flour                                100%
1 part starter                              100%

or

2 parts water                             100%
2 parts flour                              100%
1 part starter                               50%

or

4 parts water                             100%
4 parts flour                              100%
1 part starter                               25%


As you can see the difference is into the starter ratio. We will see later what does it change.



About the flour:

As in the Pasta madre, you can use different flours. Usually the flour for this ferment should be white and with a good protein content (<11%).
However different kinds of flours can be used, from high extractions to whole wheats and of course flours from different kind of cereals.
Mind that higher the ash content, the faster the fermentation will be. Therefore ripen times will change accordingly.
Nowadays it s more and more used to make liquid sourdough from spelt (if baking spelt bread), barley, oat etc...


About time:

When a healty starter is used to build this ferment, it will ripen in 3 hours at 25°c. Time may vary using different flours and ratios as I mentioned before, as higher extractions flours tend to speed up the fermentation and shorten the ripen time; Meanwhile ratios will change ripen time and characteristics of the pre-ferment. Here is how:

The 1:1:1 ratio is the faster build and can be used to bake in 2 to 4 hours (25°c). Is the best way to refresh if you need a young sourdough.
The 2:2:1 takes 4 to 6 hours (25°c). It gives you more activity and therefore more acidity.
The 4:4:1 can take up to 12 h (25°c) and will give you the more complex flavours and acidity.

This recipe can be used as a stand alone pre-ferment as well as a proper culture that can be refreshed and stored.
If using different flours, (i.e. whole wheat, spelt etc..) this difference can be quite remarkable.
In the first case, you will have a pre-ferment which is strong and will rise your breads with ease but will lack specific characteristics of the used flour because the bacterias don't have the time to set a new balance in the new substrate.
In the second case, after a period of refreshings (from 1 month it will be noticeable) you will have a proper specific liquid sourdough, with a strong character which also lead to a more complex flavour and different textures in final products.


Considerations
If you want a mild lactic sour flavour, good keeping quality and very good volume, this sourdough is the one you want to use.