Sourdough can be made from many different types of flour—each with their own flavors, aromas, and nutrient profiles—which explains how sourdough bread can taste so different from one loaf to the next. The more ash the flour contains, the more volatile compounds will be created, and over 540 compounds have been found in sourdough bread. The amount of used sourdough in bread preparation is also crucial. Due to dilution with other ingredients, many of esters generated during fermentation might disappear, but some of them can increase during baking. Many new compounds are also created with high oven temperatures.
Wheat vs rye sourdough
The most common sourdough types are wheat and rye. There are significant differences between these two cereals. In both type you will find fruity, floral, and honey undertones, though there are extra-strong rose and fruity apple aromas in rye sourdough.
Wheat sourdough possesses creamy coconut notes from lactones, while rye is less creamy and more tropical banana and pineapple-like with an additional citrusy / orange aftertaste.
Rye sourdough produces an extra buttery taste and roasted malty popcorn flavor, though t is poorer in spiciness notes in comparison to wheat. Instead, rye carries more vegetable aromas, especially potato, and is more nutty. Rye is commonly blended with wheat because its proteins can’t form an elastic network like the gluten in wheat due to present glutenin molecules that are not able to create long chains. Its starch-digesting enzymes also tend to break down the structure of the dough. Together, rye gives a distinctive flavor while wheat provides the proper texture.
Sourdough rye bread
Baking changes the aroma profile of rye, creating new molecules that offer woody, spicy, roasted/fried notes. Even existing compounds are increased significantly during baking, as much as sixfold in the case of green / fatty (E,E)-2,4-decadienal. Maple notes are also enhanced. A concentration of β-damascenone also boosts the rye’s fruity apple-like aftertaste.
In comparison to wheat sourdough, which possesses only one buttery molecule, 2,3-butanedione, rye sourdough bread has an extra called 2,3-pentanedione, providing a more buttery aroma.
Maillard reactions occur in the bread’s crust during baking, generating a wide range of aromas, like roasted fried popcorn-like notes with some woody smoky scent. Complex nutty and caramel notes are palpable, though not intense. The intensity of the green notes in the crust is lower than the bread crumb, but it can feature some meaty notes. Because of the intense water evaporation during baking, the crust is drier than the moist interior, creating a blend of crunchiness and softness.
Pairings Bread is always perfect base for sandwiches. Rye sourdough pairs especially well with Polish cottage cheese, Camembert, Chavroux, Maroilles, and Bouton de Culotte. You can also add some meat (sobrassade, salchichon, Bayonne ham, Jamón Ibérico de Bellota) or fish (anchovies, smoked salmon). Vegetables like corn salad, alfalfa sprouts, tomato, beetroot leaf, and edamame offer some freshness.
Don’t forget about a layer of butter or sour cream. Prepare French toast with this bread and serve with caramelized fruit like raspberry, figs, strawberries, durondeau pear, cranberry or grapes. If your bread becomes stale, there are still a variety of ways to put it to good use. Prepare delicious beer soup, casseroles, pudding, or Italian canederli. Transform it into breadcrumbs or croutons and put onto the top of salad for some crunchiness.
Making your own sourdough bread
Making sourdough bread is nothing complicated, especially if you already have a sourdough starter. The proportion is 3:5:2.5 (starter:flour:water). You may need more or less liquid, as the consistency of the dough depends on your ambient air humidity and temperature.
Mix your starter with water and stir until the starter is completely dissolved. Add flour and stir. Give the mixture 30-60 minutes to autolyse, during which the proteins from flour denature and create the gluten network. Add a pinch of salt and knead the dough. This is the most important step in the whole process. If you don’t knead enough, your bread will lack light airy texture. If you over-knead the dough, it will result in a very hard loaf. There is a method to check the doneness of your kneaded loaf called the ‘windowpane test’. Take a small piece of mass, flatten it, and hold it between your thumb and first two fingers. Then, stretch it into thin membrane. If it breaks or tears, it indicates that the dough is not ready yet.
Now it is time to proof the dough for 4-24 hours. Put the dough in a warm place (perfect temperature is 27-32ºC, higher will kill bacteria and yeasts while lower will slow their activity but produce more flavour) without any draft and cover with a towel. The dough should double in size, but you’ll punch it down somewhat in 4-12 hours to better distribute the gas bubbles throughout the dough. Push your fist gently but quickly into the center of the dough. Take the edges to the middle and pat the dough on floured board, then knead several times. Divide the dough into two and place them in moulds. Proof again.
Before baking (30-60 minutes in 200ºC to obtain 90-95 ºC in the centre of the loaf), make an ‘X’ on the top of the dough with a sharp knife to allow expansion without undesirable splitting in unexpected places. Once the dough is complete, allow it time to rest. Good luck keeping your hands off once you smell the rich aromas!
More information on sourdough can be found on the queste for sourdough
Advantages of sourdough
Sourdough is ripe with health benefits. It lowers the Glycemic Index (GI) of a bread loaf from 71 to 54, making it ‘low GI food’. As different acids are created, the pH lowers and the phytate concentration decreases even by half. Phytic acid,a harmful compound, is degraded in sourdough as well. It is considered an antinutrient because it produces binding minerals (in the form of phytate) in the digestive track and makes nutrients less available for the body. Therefore, bioavailability of minerals, free amino acids and protein as well increases. During sourdough fermentation, gluten may be fully hydrolysed and then safe for people with celiac disease.
Usage of sourdough can also reduce the amount of salt that’s needed for a rich taste. It helps in managing of irritable bowel syndrome (IBS). There are some benefits for shelf-life as well. Bacteria from the sourdough delay starch retrogradation, and acids provide resistance to microorganism growth, so each loaf can last a little longer than other types of bread.