Introduction: Sourdough Demystified (Updated June29)
Finalist in the
Scanpan Family Recipes Challenge
The following are very common questions and valid concerns that beginner bread bakers seem to get hung up on.
- What do I add, when do I add it, how much of it do I add, WHY do I add that?
- What is the dough supposed to look like, what is the dough supposed to feel like? How firm should it be?
- How do I know when the gluten is developed enough?
- What the heck is the difference between unbleached bread flour, and bleached all-purpose flour? Does it really make a difference?
- Do I really have to knead the dough for THAT long? It is so tiring. (The quick answer is, it depends on your dough)
- Do I really need a stand mixer? (no of course not. enough said)
Baking bread has been a long time tradition in my family. My mum grew up eating home-made bread and bread products, and so did I. With all of the new hyper-processed whipped (not leavened) breads, I have slowly been switching my family over to a variety of slow, real foods. Sourdough has become a staple food in my house. It is rare indeed to not have a loaf sitting on my cutting board waiting for someone to hack off a slice for a nice healthful snack.
Step 1: Equipment
- A good mixing bowl (I like the cambro 3 and 5 qt round containers found on amazon)
- A bench knife (keep it simple and sturdy. $10 or less should do it)
- Bowl scraper. The best $0.75 I ever spent.
- A set of sturdy wooden spoons. $2-$20
- A simple digital kitchen scale, weighs up to 5 kg in 1g increments. $5-$150. I bought a nice looking scale for $20 from my local supermarket. Don't bother with the expensive ones, they break just as quickly. I'd rather have a $20 paper weight than a $150 one. My only ask is that it measures within 1g accuracy. For 99.9% of baking jobs, this is plenty accurate.
- One or Two pizza stones. (One for the bottom of the oven, and optionally one for the top.)
- An oven thermometer
THESE are my favorite ones. They are nearly indestructible, dishwasher safe, approved for a commercial kitchen, a good deal, and ridiculously easy to clean. Big enough to brine a turkey, small enough to fit in my cupboard.
A bench knife is a fantastic tool. It allows you to simply and quickly divide dough. It also doubles as a bench scraper, an ingredient picker upper (you don't drag your knife along your chopping board do you?) a garlic masher, a dough stretcher and a ruler. Don't cut your dough with a good knife as the gluten strands are tough on the edge. I use THIS one. Sturdy like an oxe, cheap, easy to keep clean and useful.
A bowl scraper. Bowl scrapes are used to scrape ingredients off of the walls of your bowls and back into your dough. They make clean up a breeze, because you scrape all the bits off the wall of your bowl back into your dough. This minimizes the amount of cleaning and scrubbing dried goop off the side of your bowls. In addition, if you get all your flour and water into your dough, you will get more consistent results and use less flour. If you are really cheap, and can't afford the $0.75 for this tool...use an old starbucks card. Works almost as well as the real thing. I got THIS one for 75 cents on sale at a local kitchen store. These are really fantastic for scraping down batters and cake doughs. Just get one okay?
Wooden spoons...enough said. They don't wreck your mixing bowls, they are sturdy and double as a tool for disciplining unruly children (I am joking of course).
If you buy only one thing from my list of equipment, get a kitchen scale. Nothing will improve your baking more than a kitchen scale. Flour and water should be weighed by mass and not volume. Different flours pack down differently, they contain different moisture levels and grain size. 1 tsp of kosher salt is not the same as 1 tsp of table salt. 10g of table salt is the same as 10g of kosher salt. Nothing will improve the consistency and quality of your baking more than a scale. Seriously. I use my scale to make coffee, bake bread, portion dough, and many many other things.
Pizza stones are great for a couple of reasons;
- They improve your bottom crust quality by sucking moisture out of your dough.
- The increase the thermal stability of an oven dramatically. If you don't have a pizza stone in your oven, the temperature can swing upwards of 80 degrees every time you open your oven door. A pizza stone acts like a heat battery. It sucks up heat, and when the ambient temperature drops below the temperature of the stone (when you open the door) it releases heat. This means you have more consistent and even heat throughout your oven. Less hotspots, more good spots. I use one on the bottom and one on the top. This mimicks the effects of a wood brick oven.
Step 2: Flour
What is the difference between unbleached and bleached flour?
Bleached flour has been processed with a chemical that whitens it after it was milled. Untreated flour tends to be more yellow than white. Bleached flour has less of its protein intact, which means less chewy bread (and more nasty chemicals). A typical bleaching agent used in the united states in Benzyl Peroxide (the same one used to treat acne. Do you really want that in your flour?)
Freshly milled flour tends to be yellow, which is from the xanthophil pigments that the grains contain. Over the course of several months, these xanthophils are naturally oxidized by oxygen. Unbleached flour tends to be more expensive, because it takes longer to make.
All purpose vs Bread flour vs Cake flour
The primary difference between the 3 common flour types have to do with the protein content. Different wheat berries contain different amounts of protein.
Bread flours are typically made from a hard red winter wheat flour. They typically contain 13-16% protein.
All purpose flours typically contain 10-12% protein
Cake flours typically contain 8-10% protein.
What the heck does the protein do?
In flour, protein is gluten. The higher the protein content, the more potential a flour has to form long, strong gluten fibers. Gluten fibers are what holds your dough together, gives it elasticity, and chew. A higher protein content translates into a heartier chewier bread that can handle extended rising periods. A lower protein content translates into a more delicate pastry. What is the difference in texture between a cake and a good chewy sourdough? One is delicate, easy to eat and soft the other is chewy, and gives your jaws a workout.
Whole Wheat vs White vs Rye
First of all, Rye isn't wheat. It contains a whole lot less gluten than wheat and tends to have a heartier flavor. The sole difference between white and whole wheat flour is the inclusion of the bran and germ portion of a wheat berry. White flour is straight up endosperm (the starch/energy reserve of the seed). Most grains consist of a bran, germ, endosperm and aleurone layer. A notable exception is the corn kernal. It has a bran layer, and a honking load of endosperm. Next time you are eating corn-on-the-cob...you MUST yell "I AM EATING A HONKING LOAD OF ENDOSPERM".
Step 3: Commercial Vs Wild Yeast.
First of all, lets get this straight. Bakers/Brewers Yeast (Saccharomyces cerevisiae) are not bugs or bacteria. The scientific name describes what they are. Saccharo means sugar, myces means fungus. They are a unicellular fungus that like starch/sugar. They are not a type of mould, as moulds tend to be multicellular.
Commercial yeast have been cultured to produce consistent results quickly. They produce a lot of carbon dioxide (CO2) and alcohol. The CO2 produced by yeast is trapped by the gluten strands in bread. The CO2 is what is responsible for making bread rise. When bread dough is heated, the trapped has expands results in more dough rise. Commercial yeasts have been optimized to work at a pH range from about 4.5-6.5. Most commercial yeasts are fairly acid sensitive.
Wild yeasts (Saccharomyces exiguus) are generally acid resistant, which is why sourdough is sour. A sourdough starter is a type of S.C.O.B.Y (Symbiotic Colony Of Bacteria and Yeast). Sourdough starters typically contain acid resistant wild yeast and a host of lactobacillus bacteria. Lactobacillus bacteria are responsible for the sour taste in sourdough. The acid produces by lacto-bacillus lowers (makes more acidic) the pH of the dough, which in turn makes it a more hostile environment for other types of bacteria resulting in a longer shelf life. Natural preservatives, baby!
Sourdough rises more slowly than commercially leavened bread because the acid from the bacteria and the salt inhibit the growth of yeast. Generally, longer dough fermentation times result in tangier, more complex flavours. Additionally, the bacteria and yeast release digestive enzymes that break down gluten (the bread cement), which is why it typically has a more dense texture than commercial bread. These digestive enzymes apparently liberate minerals and nutrients from the flour, resulting in a more healthful product. In addition, some of the simple sugars from the flour are consumed, resulting in a lower Glycemic Index, which is a good thing for diabetics.
As an aside, it should be noted that fermenting a dough for TOO long will result in the loaf failing to rise to the occasion (This brings to mind those hilarious "good morning" adverts by Viagra. These ultra sour, dense and ultimately lackluster loafs result from too much gluten being digested by the SCOBY. The cement that holds the bread together has been removed, the ability of the dough to trap CO2 has been compromised hence a flat loaf. Imagine removing the mortar from a brick wall... you get the idea.
Step 4: Ingredients
Flour: Duh, carbohydrate source. Food for yeast, humans etc, the main ingredient in bread. See protein content discussion in step 2.
Salt: Salt seasons the dough. It brings out the various subtle flavours of the flours being used. In addition, salt is a preservative (slows bacterial growth, increases shelf life) and slows the process of yeast fermentation (slower fermentation = more flavour)
Oil/Fat: Increases the palatability (texture/tastiness) of food. Decreases the crispiness and chew of bread. Think how chewy a lean sourdough bread is compared to an enriched (fat added) sandwich loaf is. The sandwich loaf is more cake like, more tender/soft and less chewy. The simple addition of fat to a lean (fat free) loaf can change it from a wonderful chewy loaf for soups to a great loaf for PB and J. Fat also increases the shelf life of food by slowing down the process of oxidation. Oxidation is a fancy way of saying the bread is stale.
Eggs: Eggs bind the ingredients in a dough together. They increase the fat content (fat soluble caretenoids found in the yolk) and increase the palatbility and richness of a dough. Eggs also increase the rate of crust browning. Cakes have fats and eggs, lean doughs do not.
Water Changing the amount of water in a dough can change a dough into a batter, a bagel into a loaf, or a biscuit into a pancake. Dough's are typically rated on a scale of % hydration. A 50% hydration dough means that for every 100g of flour, there is 50g of water. If a recipe expresses water as a percent hydration, you know how sticky, slack, firm or loose it should be. Dough hyrdrations usually range from 50-55% (bagel) to 80% (a high hydration baguette). The amount of water is also directly related to how open or closed the crumb is. The higher the hydration, the more open (bigger holes) the crumb tends to be. The percent hydration also effects how you are going to develop gluten. Lower hydration doughs are kneaded, higher hydration doughs typically use stretch and fold techniques.
Step 5: Recipe - the Sponge (Day 1)
The Recipe (Don't ask for cup measures, I don't bake using volumetric measures. Measuring cups are for kitchen sissies):
- 70g of 50% hydration starter (I am working on a sourdough starter Instructable, until then search "freshloaf.com" for good information). A 50% hydration starter is solid and clay like NOT liquid.
- 140g of unbleached bread flour (the picture shows 142g, not a big deal).
- 90g of Whole Wheat Flour (the picture shows 85g, I ran out of flour :D)
- 150-160g water, room temperature
- Pinch off a golf-ball size piece of starter (about 70g). Rip it into many pieces, and put it in your non-metallic bowl.
- Add the water, and whisk until lumps are gone (this facilitates even culture distribution in your sponge. You don't HAVE to whisk it, but it means you need to mix less later.
- Add the flour, and then mix with a wooden spoon until it comes away from the walls of your mixing bowl. Scrape the sides of your bowl with a dough scraper and incorporate as much of the flour as possible. If its in the bowl, make sure its in your dough.
- Let your dough rest for 5-15 minutes. This rest period lets the bran (the wheat fiber) absorb any water it is going to absorb. Your dough will probably go from a sticky mess into a less sticky mess. You want your dough to be slightly tacky (a dry finger poked will come away with a little bit of dough. A sticky dough = your dry finger comes away covered in dough). Slowly add flour (or water) until your dough is the right consistency. You should be pretty close though. Err on the side of sticky fingers, because nobody likes a crusty dough ball.
- Knead your dough on lightly floured surface for 30 seconds until the dough is evenly combined (one texture, no lumps of white and brown). I normally just knead the dough right in the bowl, saves me from having to clean up your counter.
- Transfer your dough to a lightly oiled container, covered loosely for 6-12 hours until doubled in size.
- Refrigerate your sponge overnight (This is called a dough retard. It slows the yeast ferment down, resulting in a more sour and flavourful dough. Don't skip this step, it is important.)
Dry tools/hands and wet doughs don't mix. Dry doughs and wet tools don't mix. When working with sourdoughs, I keep a container of water beside my workbench that I throw my tools into when not using them. This way, I always have a "non stick" tool ready to go. You'll notice that in the kneading video I touch the dough and I get dough all over my hands. I wet my hands and presto-chango no dough sticko. Right at the end of the video, you'll notice me demonstrating a tacky dough. Notice how the dough doesn't come away with my finger.
If you start this process early enough in the day, you can just add an hour to the ferment period and go right ahead to the dough mixing stage. This way, you can complete a loaf in two days. I haven't noticed any huge differences in rushing the retard.
A wetter starter favours the production of yeast, a drier dough favours the production of lactobacillus (it has to do with the concentration of acid spread out across the amount of water. Less water higher pH, the harder it is for yeast to compete with the lactobacillus. I like to keep my starter at 50% hydration because it is less likely for other bacteria to get a foot hold. I like my sponges at about 70% hydration because it is more yeast friendly. Using a lower hydration (less water) on a sponge results in a more sour loaf.
Kneading the sponge/dough.
Total Active Time invested thus far: Less than 5 minutes.
Step 6: Day 2 - the Dough!
- Cut all of the starter from the previous day into 10-20 pieces, and place in a mixing bowl
- Add the Water, and let stand 5 minutes. This will soften the pieces of starter and allow for easier mixing!
- Whisk the starter and water until it is well combined and looks like a batter
- Add flour and salt, mix with a wooden spoon until it resembles a shaggy mess. Let stand 5 minutes
- Your dough should be very sticky, add flour (or water if it is dry) and mix by hand until the dough is slightly tacky. You can tell it is ready if a dry finger comes away from the dough with only a small amount of dough stuck to it. Once the proper consistency has been achieved, let stand for 10-15 minutes. Don't make the dough too dry, otherwise the final crumb will be dense and nasty.
- Spread your dough out on a lightly oiled surface by reaching under and pulling it outward. Stretch the dough as far out as it will go without tearing. You should feel it resist you. Do a complete letter fold stretch and fold. Let it rest for 10-30 minutes. Complete another stretch and fold. Let it rest again, and then do a final stretch and fold.
- Allow your dough to sit in a covered bowl for 4 hours.
- Divide your dough into two loafs, and then put them into lightly oiled well covered containers. Store in the refrigerator over night
Step 7: Day 3 - Baking Day!!!
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