Food EditionGrowSideFrenchKeeping Your Sourdough Starter Alive
10 minIntermediate
Side · French

Keeping Your Sourdough Starter Alive

A healthy starter is a consistent cycle of feeding and temperature management. Keep it in a glass jar, discard all but a small portion of the culture, and add equal parts fresh flour and water by weight until the mixture consistently doubles in volume within four to six hours.

Total time
10 min
Hands-on
10 min
Difficulty
Intermediate
Before you start

Consistency is the only metric that matters.

Your starter is a living culture; it will adapt to the temperature and flour you provide. A neglected jar will grow dark liquid on top, but it is rarely dead—it is just hungry.

  • Glass jar with loose-fitting lid
  • Digital kitchen scale
  • Silicone spatula
Ingredients

What goes in.

  • 50gmature starter
  • 50gall-purpose or bread flour
  • 50gfiltered water at room temperature
The key technique

Discarding to Control Volume

If you do not remove the majority of the old culture, the volume of flour required to feed it becomes unsustainable. Always scale back to a base amount before adding fresh nutrients.

Step by step

The method.

  1. Weigh the jar

    Place your clean glass jar on the scale and tare it. Add 50 grams of your existing starter.

  2. Add fresh feed

    Pour in 50 grams of water and 50 grams of flour. The mixture should be a thick, uniform paste.

  3. Mix thoroughly

    Use the spatula to ensure no dry flour remains at the bottom or sides of the jar. Scrape the walls down so the surface is clean.

  4. Mark the level

    Place a rubber band around the outside of the jar at the level of the mixture. This is the only way to accurately track growth.

  5. Ferment

    Set the jar in a draft-free spot. When the mixture reaches the rubber band's height or higher, it is ready for use or refrigeration.

Tips & troubleshooting

When it doesn't go to plan.

Tip

If you bake infrequently, store the jar in the back of the refrigerator. Feed it once a week to keep the yeast population robust.

Tip

Dark liquid on the surface, known as hooch, is a sign that the starter has consumed all available sugars and is starving.

Tip

If the jar smells like nail polish remover, it is past its prime. Feed it immediately and move it to a slightly cooler location.

Questions

The ones that keep coming up.

Can I use tap water?

If your tap water contains high levels of chlorine, it can slow down fermentation. Filtered or bottled water removes this variable.

How do I know if it has gone bad?

A healthy starter smells tangy and slightly acidic. If you see pink, orange, or fuzzy mold, discard the entire culture and start over.