Sourdough taste different everywhere, and is not always as sour as the California style sourdough started with a
Lactobacillus sanfranciscensis starter. So it is possible you are asking about that regions unique sourness in their sourdough bread. Even when not perceived as sour, everywhere in the English speaking places they still call it sourdough as long as it began from a starter of only water and flour (rye or wheat typically). The starter will have eventually grown to include the natural bacteria of its geographical location, or other microbes transported from somewhere else via a spoonful of someone else’s starter.
One technique which makes it extra sour is to stretch the fermentation process of the final dough to be longer than one day, to 2-3 or more days. So that could be the difference of the Masa Madres breads you have tasted catering to the local tastes. Still they are real sourdough.
If you begin your own sourdough starter you will be following the exact same directions as everyone making MasaMadre in Argentina. The preparation is basically the same, but the small variances still make the flavor and texture different. Perhaps you will even smuggle in some starter from California, but the water and the flours and even the salt here will be different. It is worth mentioning that it is not possible to buy salt here that was not fortified with Iodine, which is something many bakers and cooks say makes everything taste different.
When it comes to the mecca of sourdough, separating scientific fact from lore means breaking a few taboos.
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