Sourdough Starter Care: Feeding, Discarding, and Achieving Peak Readiness
The Living Ingredient
This article is dedicated to Deb…my first sourdough starter. I may have killed her. I guess it should also be dedicated to Deb 2, Deb 3 and Deb 4 who also met their untimely demises by turning into liquid goo before ever making a loaf of bread. It is also in honor of Deb 5, when everything finally fell into place. I hope that through the tips and tricks outlined in this article you can avoid some of the pitfalls I experienced and get to making lovely sourdoughs for your friends and family.
Sourdough starter is far more than just flour and water; it's a thriving, complex ecosystem of wild yeast and lactic acid bacteria. Treat it like the delicate, living pet that it is, and it will reward you with superior flavor and lift.
Successful sourdough baking relies entirely on maintaining a healthy, balanced culture through proper feeding ratios, controlled temperatures, consistent discarding, and knowing the visual and aromatic cues of "peak readiness." This guide will demystify starter maintenance and provide the practical steps needed to keep your culture strong, predictable, and ready for your best loaves.
The Science of the Culture (The Symbiosis)
The unique flavor and structure of sourdough come from the harmonious relationship between two microbial groups:
Wild Yeast: These are the leavening agents. They feed on the sugars in the flour and produce carbon dioxide gas, which creates lift, volume, and that beautiful open crumb in your dough.
Lactic Acid Bacteria: These are the flavor creators. They produce two main acids: acetic acid (which gives a sharper, more vinegary, traditional "sour" flavor) and lactic acid (which gives a milder, creamy, yogurt-like flavor).
The goal of consistent feeding is to keep both populations thriving in balance. When a starter is "ripe," it's happy, hungry, and producing the right amounts of gas for lift and balanced acids for complex flavor.
Feeding Ratios and Hydration (The Math of Maintenance)
Feeding is the simple process of giving your starter fresh flour and water to eat. The ratio is the key to timing and predictability.
The Standard Ratio (1:1:1): The default maintenance ratio is 1 part matured Starter : 1 part Water : 1 part Flour, measured precisely by weight. This ratio ensures the microbes have enough food to reach their peak activity in a predictable timeframe, typically 4 to 8 hours at room temperature.
Example: If you keep 50 grams of starter, you feed it 50 grams of water and 50 grams of flour.
Hydration Percentage: Most common starters are 100% hydration (equal weight of flour and water), resulting in a liquid, pancake-batter consistency. This liquid consistency allows yeast and lactic acid bacteria to move and work easily. Stiffer starters (lower hydration, like 50% to 70%) are slower, less acidic, and are sometimes preferred for specific bread types.
Temperature Control: This is the single biggest factor affecting timing. Warmer temperatures (around 78 degrees Fahrenheit or 25.5C) accelerate microbial activity, useful for quick turnaround. Colder temperatures (like in a refrigerator at around 40 degrees Fahrenheit) slow activity down significantly for long-term storage, sometimes allowing you to feed only once a week.
Discarding (The Necessary Balance)
Discarding sounds wasteful, but it is a non-negotiable step in starter health and consistency.
Why Discard?: If you don't remove a portion of the old starter before feeding, the culture grows exponentially, and the microbes rapidly use up the available food. The culture quickly starves and becomes overly acidic, producing a weak starter that smells sharply of vinegar. If you see a layer of gray liquid on top (called hooch), the starter is signaling intense starvation.
The Process: To maintain a small, manageable volume and a consistent pH level, always remove a large portion before feeding (usually leaving behind only 50 to 100 grams of starter total).
Use it, Don't Waste it: The discard doesn't have to be thrown away! It can be used for excellent discard recipes like pancakes, quick crackers, waffles, or chocolate cake, which all benefit from the sour flavor.
Achieving Peak Readiness (Visual and Float Cues)
Timing is everything in sourdough baking—you must catch the starter at its most active, gaseous point, known as peak readiness.
Visual Readiness: The starter is ready to use when it has doubled or tripled in size and has a rounded dome on top, as opposed to a peaked center, which indicates activity is slowing. Look for lots of bubbles breaking the surface and streaks of bubbles along the sides of the jar.
The Float Test: For absolute certainty, drop a small spoonful of starter into a clear glass of water. If it immediately floats on the surface, it's perfectly full of carbon dioxide and ready to use. If it sinks, it's either under-active or past its peak (it consumed all its food and collapsed).
Aroma Cues: A ripe, happy starter should smell pleasantly sour, yeasty, and slightly fruity, like a fresh beer mash. A sharp, pungent, vinegary scent signals that you missed the peak and the culture is beginning to starve.
The Living Ingredient's Promise
Your sourdough starter is truly the living heart of your bread. Sourdough success is simply about being attentive to the needs of your culture: feeding it consistently at the right ratio, managing its volume through discarding, and using it at the precise moment of peak activity.
By understanding the science behind the symbiosis of yeast and bacteria, and by listening closely to your starter's visual and aromatic cues, you ensure every loaf has the maximum lift and the complex, authentic sour flavor you seek. Embrace the journey of caring for your culture—it’s the most rewarding step in the entire baking process!