Long before instant yeast was on the market, bread bakers had to maintain and keep their own living yeasts to proof their breads. Since yeast are living micro organisms quite some care has to go into these cultures to make sure they would stay alive. A dead yeast won’t rise your bread.
One way to maintain these yeasts is by maintaining a starter, often called sourdough starter. These starters are mixtures of yeast, water and flour in which yeast thrive if fed regularly. It’s not only yeast that can live in a starter, a wide variety of other micro organisms, e.g. lactic acid bacteria may live in it as well. This will result in not only a nicely risen bread, but also a distinct flavour.
Nowadays, most manufacturers use some sort of dry yeast that can be stored for long periods of time and has a pretty constant behaviour. But not all of them have though, some continue to cultivate and maintain their own yeasts. One of these bakeries, who also managed to make a hugely touristic attraction out of its bakery, is Boudin Bakery. This bakery has apparently been baking with the same sourdough starter for more than a 100 years!
What’s a sourdough starter?
A (sourdough) starter is a mixture of flour and water in which yeasts and other micro organisms have been cultivated. The yeast in the starter will rise your bread and other micro organisms will contribute to the flavour. Everyone can make and maintain their own starter.
Since a starter is alive, it is important to keep it alive as well. This is done by continuously feeding it with new flour and water in between your baking. A starter is added to the dough at the start of the kneading process and will be an inherent part of the bread.
Boudin Bakery is a San Francisco based bakery, started in 1849 by the family Boudin. At the time, baking with sourdough was very common, most bakeries in San Francisco had their own starters for their breads. However, as the industry grew larger and more industrialized, it became rarer to solely use a starter as a leavening agent. Boudin bakery though continued to bake with their sourdough only, creating a bread with its own unique characteristics.
Nowadays Boudin Bakery is a bakery + restaurant + tourist shop + museum in one. It’s a brilliantly smart concept, they’ve managed to transform a regular bakery into a hugely popular touristic attraction. You cannot walk through the bakery of course, but there’s a walk around the top of the bakery, allowing you to look into the bakery from the top. One of the main pieces of equipment is a huge cooler in which the starter, or mother dough, is kept. This mother dough they claim, is more than a 100 years old. Whether that’s relevant is another matter (yeasts themselves don’t live that long, so it has been refreshed over the years of course).
The Boudin Sourdough bread
Despite the name, a sourdough starter certainly does not have to make a sour bread, this entirely depends on the composition of the starter. That said, the basic bread from Boudin Bakery is quite sour. Apparently, they’ve cultivated their starter in such a way that it makes a pretty sour bread. This is also what makes starters so unique. Each region will have its own micro organisms thriving in the local conditions. As a result, starters will tend to taste different (at least slightly) everywhere. In the San Francisco pier this sour composition seems to thrive.
Shelf life & sourdough
It is often said that sourdough breads keep longer than bread with a shorter rising time and made with dry yeast. In the case of Boudin Bakery this definitely is the case. Whereas most baguettes will dry out pretty quickly, the Boudin baguette was still perfectly good 1-2 days after purchase. For a home made freshly baked bread without any preservatives, this is pretty special.
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Visiting the museum & bakery
When visiting Boudin Bakery you cannot walk through the bakery itself of course, but, as mentioned before, you can watch the bakery through various glass panes. Within the one hall the entire bread baking process takes place.
At the top bakers blend the ingredients to make the doughs. This dough is portioned out automatically by a simple smart machine and risen in proofing machines below. After proofing the doughs are shaped. The more complicated doughs are shaped by hand (e.g. they sell a bread shaped like a crab, bit too touristy, but apparently it works), but the more basic versions are shaped by machines.
After a final rise the breads are baked in the oven. The finished breads are placed on tray and in baskets. There are even baskets on a rail system which circulate through the shop and bakery. It can be used to move bread from one side to the other, but it’s probably also a nice show for visitors and helps to spread the delicious smell of bread through the whole building.
Whether or not a sourdough starter should be old seems to be a common discussion within sourdough bread baking world. This podcast from Modernist Breadcrumbs shines an interesting light on whether that is indeed necessary. Long story short, once the micro organism culture has established itself, year long cultivation won’t really improve it any further. Nevertheless, managing to keep a starter up and running for years and years is a real achievement.