Types of Starters in Baking

When it comes to starters you may have heard the terms Mother, Levain, Sponge, Sourdough, Poolish, Biga, Preferment, Instant Yeast, Fresh Yeast, Active Dry Yeast (ADY)… the list goes on and on. But what do all these terms mean? 

A starter is a leavening agent that is fermented before all of the ingredients are combined. In other words, a starter is a small portion of dough that has already started to develop and ferment. Starters are what make baked goods rise and are an alternative method to direct methods of dough making. 

Direct methods? 

Yes! There are two categories to leavening dough: Indirect Dough Methods and Direct Dough Methods: 

1. Indirect Dough Methods are when the ingredients are combined in more than one phase and include preferments. The first phase is making a starter. This prolongs the process since the starter needs time to develop. The second phase is adding this pre-fermented portion of dough to the remaining ingredients and creating a final dough. Since your final dough includes some dough that has had a head start on developing, the overall mixing time is reduced.
2. Direct Dough Methods are when all dry and wet ingredients, including the yeast are mixed at once. While you may not pour all the ingredients into the mixer and then start it, (baking is a science and order matters!), you will add all of the ingredients in one phase. 

Let’s examine some types of starters and terms that are used in Indirect Dough Methods:

Preferment: the portion of a dough that is made is made in advance of the final dough. This portion of dough is fermented before being combined with the remaining ingredients. The final dough will also ferment before being shaped and baked. 

Mother: a preferment made of just water and flour that sits for a few days and develops wild yeast from the naturally occurring lactic acid bacteria (LAB) found in the air and flour. A mother must be “fed,” “maintained,” and “refreshed” to stay active and can last for years! You may know of bakeries or friends who have had mothers that have been passed down through generations! 

Levain: another name for a mother. We’ve also seen recipes that refer to levains as the portions of a mother that are used in a recipe. 

Sourdough: another term often synonymous with mother and levain as it is also a preferment made of just water and flour that ferments from wild yeast. The “sour” in “sourdough” comes from the flavor that results from the natural fermentation of the wild yeast and bacteria. 

Sponge: a preferment made of flour, water, and a small amount of yeast that is often used to enhance the flavor and texture of the final product. 

Biga: a stiff sponge that is generally two parts flour and one part water (2:1 or 50% hydration) with a little bit of yeast (typically around 1% fresh yeast), a Biga is often used to enhance the structure, rise, and flavor of dough. When making a biga, don’t expect your dough to be smooth and shiny. Instead, you’ll have a very dry, rough, and crumbly mixture that will come together as it rests. 

Poolish: a loose sponge that is 1 part flour and 1 part water (1:1 or 100% hydration) with a little bit of yeast (less than 1% fresh yeast), a Poolish is used to enhance the flavor of dough. 

Pâte Fermentée: a preferment that consists of a saved piece of dough from an old batch that is used in a new batch. Because it comes from a completed and mixed dough, it contains salt and usually only lasts for a few days in the fridge.

Wild Yeast: naturally occurring, wild yeast (single celled organisms in the fungus family) grow everywhere - in the air, on your flour, on plants, on fruits, on flowers, in soil, and on skin. In fact, there are more than 1,500 species of yeast, 250 of which can convert sugar into CO2 and alcohol, and 24 species of these 250 make our food taste good. In dough, wild yeast are the combinations of these wild species that create fermentation. 

Commercial Yeast: commercial yeast comes from the fungal species, Saccharomyces cerevisiae which means “sugar-eating fungus”. This is one of the 24 species of yeast that makes our food taste good and it has been used since the 19th century. Commercial strains of S. cerevisiae are selected for their flavor, aroma, and fermentative abilities. 

Baker’s Yeast: another name for commercial yeast.

Dry Active: a type of commercial yeast also referred to as Active Dry Yeast or ADY, this type of yeast is a granular living organism that must be dissolved in lukewarm water to be “activated” or “awakened.” If the yeast is alive, you will see it begin to dissolve, bubble, and foam within minutes. Once the yeast has fully dissolved and bubbled, it is ready to be combined with the rest of your ingredients. 

Instant: a type of commercial yeast also referred to as Rapid-Rise Yeast, this type of yeast has smaller particles which dissolve more quickly than Active Dry Yeast and does not require proofing (activating). Instead, Instant Dry Yeast can be directly added to your dry ingredients. 

Fresh: a type of commercial yeast also referred to as Cake Yeast, this type of yeast is not pressed and dried and therefore has a shorter shelf-life. Fresh yeast must be refrigerated as it consists of moist and active fresh yeast cells. Often resembling a pale brown, beige, or grey brick or block, it is soft and crumbly. It should be crumbled into smaller pieces when being used, and proofed like Active Dry Yeast in warm water before being combined with the remaining ingredients.

*Converting Fresh and Dry: The general rule of thumb is that you use ⅓ the amount of dry yeast that you would fresh or 3x more fresh yeast than you would dry. So, if you were going to use 3g fresh yeast, you would use 1g dry yeast, and if you were going to use 2g dry yeast, you would use 6g fresh yeast. With Caputo Lievito, you can go up to 70% of fresh yeast (or ⅔), so if your recipe calls for 3g fresh yeast, you can use 2 grams of Caputo Lievito.

Caputo Yeast: a high activity yeast that yields better results in long fermentation and does not need to be activated in water. It works slower in the first period and then starts releasing a higher quantity of gas in the sequent phases to guarantee gradual and consistent gas production during the entire leavening period. Our yeast is obtained from Italian molasses (a particular type of sugar obtained from beet and sugar cane) and dies completely at 58 ° C. Therefore, it is easily digestible unlike chemical yeasts which may collapse due to long fermentation but won't die during cooking.

As you experiment and bake, you will find that different recipes will call for different types of starters and yeasts depending on the characteristics (elasticity, density, flavor, etc.) each creates. Some final reminders to keep in mind: 

1. When using preferments, always be aware of hydration levels. If you use a poolish, you will close your dough with less water than you would if you used a biga. 
2. A pâte fermentée includes salt, so you will use less in your final dough than you would if you were using a different type of starter. 
3. Wild yeasts are what create mothers, levains, and sourdough starters. 
4. Commercial yeast consists one one species of yeast and can be found in dry and fresh applications which determine the quantity you should use and the way in which you use it. 
5. Starters and yeasts release carbon dioxide as they feed on the sugars in your dough making it rise!