Sourdough has a long and varied history, starting with the ancient Egyptians, and the creation of a sourdough mother is probably one of the most enduring and useful of all scientific endeavours.
Until commercial baking yeast became widely available in the 19th century, sourdough baking was the norm, but it lost prominence to mass-produced, flavourless, textureless ‘bread’ throughout the course of the 20th century. Except for small communities and pockets of artisanal bakers who have kept the art alive – an art that is rapidly becoming mainstream again. Sourdough baking is the new in thing so, if you’re looking for an interesting science project to do with your stay-at-home kids, this has multiple benefits: it’s biologically fascinating, it’s useful, it will contribute to creating a culture of healthy eating, and – best of all – it’s fun and delicious.
What is sourdough?
Sourdough is a dough that contains yeast as well as at least one Lactobacillus culture. The yeast is what causes the dough to rise, while the Lactobacillus cultures add the sour, tangy taste. Due to its slight acidity, sourdough has better keeping quality than non-sourdough bread, and many people love its characteristic taste.
Sourdough connoisseurs appreciate regional differences in sourdough flavours. These differences arise mainly from the fact that each region has a different mix of bacteria in the sourdough starter, which results in slightly different tastes.
Making your own starter
Sourdough baking may seem intimidating at first, but once you get into it, it’s surprisingly simple. The first step is to get your hands on a sourdough starter. Often, bakeries are more than willing to share their starters, or you can buy one commercially.
However, the best way to get into sourdough baking is to make your own starter. All that you need is flour, water, a jar and a kitchen scale.
- Flour: any type of flour will do, as long as it’s unbleached. Bleached flour may have some residual bleach that can kill off any budding organisms, and it’s unlikely to have any surviving microflora so, while it’s not impossible, it’s much trickier. We’ve found that whole wheat flour works the best, with rye flour coming in a close second. Don’t worry that the make-up of your starter will influence your final bake. Often, you only use a tiny amount of starter, so you can easily bake white flour bread with rye or whole wheat starter.
- Water: preferably distilled, but tap water works fine – preferably filtered. Make sure it’s lukewarm to promote quick growth.
- A jar: any type of clear glass jar will work. Try to avoid opaque jars, since they make it difficult to determine when your starter is ready for use.
- Scale: if you want to be a baker, you’re going to need a scale. There are many high-quality, affordable scales offered online.
It’s a simple process but it is quite long, so it requires some dedication and discipline. On the first day, set your scale to zero with the jar on it. Measure out 50 grams of unbleached flour and 50 grams of water into your jar. Mix the two thoroughly and scrape down the walls of the jar. You should end up with a thick paste. Let the jar stand in a warm spot for the rest of the day. In the evening, discard half the starter (leaving you with 50 grams in total) and then feed with 50 grams flour and 50 grams water again. The reason you want to discard most of the starter is that you want to keep feeding your starter double the amount of flour every time you feed.
It may seem wasteful, but discarding at this stage will ensure that you’re feeding all the bacteria and yeast in the starter, without having to add kilograms of additional flour. Once your starter is established, you can use this excess sourdough for all sorts of other delicious baking projects.
Repeat this process of feeding twice a day until you notice bubbling and the sourdough expanding. You can expect to see this happen from three to seven days after your first feed.
Unfortunately, seeing signs of life doesn’t mean that your starter is ready for use just yet. Keep feeding your starter twice a day until you start noticing a consistent doubling of the starter. Use a marker to help you keep track of your starter’s growth during the day.
Once your starter doubles predictably, you should be able to bake with it. A good test is the float test, where you put a little dollop of starter into a glass full of water. If it floats, you’re ready to go.
Maintaining your starter
Once you have an active starter, maintaining it is easy. Keep the starter in the fridge and feed it around once a week, with 50 grams flour and 50 grams water. You can leave it longer, but it may take several feedings to revive it. Don’t worry about any liquid that accumulates at the top of your starter; just mix it back in. Often, the more juice you have, the tangier your final bread will be.
When you want to use your starter, take it out around four to eight hours before your bake and feed it. It should be peaking by the time you start baking. Return the rest into the fridge.
Help! My starter is taking over my fridge!
You’ll quickly get to the point where you have more starter than you know what to do with, especially if you’re baking often. While you can throw it away, there are plenty of things you can make with the unfed starter, including pizza, scones, cake, doughnuts, waffles, and anything else you can imagine. Don’t be afraid to experiment and reap the results of your hard work. And, yes, you can put some in a pretty jar, tie a ribbon around it, and give it to a friend.