The science behind sourdough and tips for easy maintenance of a sourdough starter.

One of my favorite topics, let’s dive into the science behind sourdough and I’ll give you my tips for easy maintenance of a sourdough starter, plus my journey into sourdough and tidbits of info I think you’ll find helpful on your sourdough journey.

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I started out just like many of YOU…

If you really know me, you know I’m a sucker for a slice of bread, fresh out of the oven and slathered with butter. For many years I made bread with instant yeast, unknowing of another way. But even then, I would hear the term “sourdough” periodically. The first thing that always came to mind was what a lot of people call Amish friendship bread. it sounded complicated and time consuming. I never once gave it a second thought. But in the last couple of years sourdough has become pretty popular and piqued my interest.

After reading Wild Bread by Lisa Rayner, I attempted to start my own sourdough starter. Keep in mind the only other fermentation I had ever done was salt brine pickles, with mixed results. It failed, needless to say, but I didn’t give up. I tried again and failed. Slightly discouraged and impatient to try sourdough bread at this point, I purchased a live starter online. And it failed. This time not my fault, after consulting with customer care we determined something happened in transit. They sent me another and lo and behold, Sally Sourdough has been alive for over a year now! And yes, I named my sourdough starter, it’s a thing. All this to say, if I can do it, so can you!

new sourdough starter sitting on counter by farm fresh eggs — Sally Sourdough, after arrival and first feeding

What is A sourdough starter?

I’ll admit, I’m a bit of a nerd and could go on for days about this particular topic but I’ll try to break it down so it’s easier to digest (ha, sourdough pun). Bacteria and yeast are all around us in dormancy, floating through the air and living in flour. When the suitable environment (aka equal weights flour and water) is provided, they start reproducing and fermenting. These bacteria produce amino acids (the building blocks of protein), B vitamins, some carbon dioxide and a variety of other compounds which all attribute to the unique flavors and textures of sourdough bread. The acids produced by these bacteria break down most of the anti-nutritional phytates found in the bran of whole grains which leads to better mineral absorption. They also improve protein absorption by breaking up large protein chains, turning them into smaller, more absorbable bits. A study I recently read reported that the lactic acid bacteria in sourdough actually breaks down pesticides, reducing the pesticide concentration by 42%. How cool and incredibly beneficial is that in this time we’re living in with such high pesticide residues?!

You’re probably thinking “this is just flour and water; how does it rise bread?” That’s where wild yeast comes in. Sourdough yeast eat the simple sugars found in flour, including fructose and glucose, synergistically working with the lactic acid bacteria that consume maltose and glucose. When yeast have access to oxygen, aerobic fermentation produces carbon dioxide gas, which bubbles through the bread dough making it rise. Different strains of wild yeast produce carbon dioxide at different rates, leading to various leavening rates from different sourdough cultures.

bubbly and active wet sourdough starter — active “wet” sourdough starter

does it matter what flour i feed my sourdough starter?

In short, yes! However, any type of sourdough is healthier than the alternative baker’s yeast risen bread. One of the biggest factors is attributed to glycemic index. The index ranks foods from 1-100 according to how fast they raise your blood sugar after a meal. All sourdough breads have a substantially lower glycemic index than non-sourdough breads because the lactic acid produced by sourdough bacteria slows starch digestion.

Breads made with white flour and baker’s yeast have the same index as refined white sugar- 100!
Whole grain breads with baker’s yeast and sourdough breads made with refined white flower both have a mid-range glycemic index.
100% whole grain sourdough breads have a low glycemic index similar to whole grains and legumes.

If you’re milling your flour at home, the level of fineness it’s ground to will make a difference in your baking as well. Generally, the finer the grind, the stronger the gluten web and the lighter and fluffier the final bread. In addition, the finely ground flour has smaller bran particles which allows the fermentation process to break down the phytates faster, thus improving the bioavailability of the minerals in the bread.

– Wild Bread, Lisa Rayner

Can I switch flours?

Anytime you want! Currently I’m jumping back and forth between feeding mine freshly milled spelt or freshly milled hard white wheat. In the past, I’ve used bread flour, all-purpose flour, freshly milled red and white wheat, and all-purpose einkorn, all of these organic and non-GMO. You can even use gluten free flours like brown rice flour. There will be some residue from the previously used flour in the next loaf or two, but I don’t mind that at all.

How often do i have to feed a sourdough STARTER?

Cultures are living organisms, meaning they need food, shelter, rest and exercise to stay happy and healthy. But you know what? Sourdough is extremely resilient (one of the easiest cultures for beginners to learn on) and I have found workarounds to the daily chore.

Feed starter, let sit out awhile to activate and then put it in the fridge until you need it again.
Even if you don’t put it in the fridge your starter can survive for 3-4 days on the counter without being fed, it will become dormant, but you can still use it for many recipes like pancakes or crepes, then feed it again to activate it.
Keep a dry sourdough starter, more on this below.

active sponge sourdough starter with handcrafted cover — active “sponge” sourdough starter with handcrafted cover, available in our shop

what consistency is best for my sourdough starter?

The consistency of your culture can vary from a pourable, bubbly liquid, sometimes called a “wet starter”, to a “sponge-like” starter with an aerated dough, to a stiff, “dry” dough. I change the hydration of my starter frequently, depending on what I plan to make next with it. For pancakes I like a wet starter, for bread making, I like my starter to be closer to sponge consistency. I’ve only attempted to convert my sourdough starter to a dry dough once and personally, it wasn’t my favorite, but some people have great success with it, like Shaye Elliot of The Elliot Homestead. You can check out her blog for more info on dry sourdough starters.

The higher the water content, the more vigorous a culture will be. It will also run out of food faster.
Hydration levels determine the proportions of lactobacteria present in your culture. Drier starters are more hospitable to acetic acid(vinegar) producing bacteria, making for an extra-tangy flavor. Wetter cultures have more lactic acid producing bacteria, providing a milder flavor. Sponges range between the two.

Where do I start?

Starting your own starter is easy enough for most people, not for past-Jessi though. I bought mine from Azure Standard and I highly recommend purchasing a starter from them, it’s a vigorous and adaptable culture. I no longer follow the care/maintenance directions they suggest now that my starter has settled into its new environment, but I would recommend following those instructions for the first week or so to not stress the culture with too many changes at once. Recently I have come across Gem Cultures, it’s where I got all my dairy cultures, but they also have sourdough starters available. I have no affiliation with them, just an appreciation for their high-quality cultures. If for some reason you can’t purchase a starter at this time, send me an email and I’d be happy to share a bit of mine with you!

Above all else… don’t get discouraged!

Trying anything new can be overwhelming and uncomfortable, the key here is progress over perfection. You may kill a culture or two and that is okay! The learning curve is a big one and I can’t tell you how many bricks of bread and just subpar bread in general my family has choked down because I had no idea how to bake sourdough bread (more on that in a future post!). Heck I still make sourdough bricks when recipe testing, I just feed it to the chickens now (they don’t complain). But hang in there, the satisfaction of accomplishing a goal and learning a new skill is so pleasing, and delicious! So go ahead, step out of your comfort zone, just like thousands of others, me included, you’ll be glad you did!