Lab Technique · Entry 13 of 42

Culture Maintenance / Serial Subculturing

Keeping a live microbial culture alive and active by regular feeding/transfer.

How it works in the lab

Microbiologists keep working cultures alive by transferring a small amount into fresh medium on a regular schedule, a serial passage that refreshes nutrients and removes waste while staying aseptic to keep invaders out. Famous long-term experiments, like the E. coli long-term evolution project, have transferred cultures every day for decades, relying on flawless sterile technique the entire time. Consistency in timing, temperature, and medium is what makes a culture predictable enough to run experiments on.

Research Findings

Core microbiology technique used in everything from lab yeast strains to long-term bacterial evolution experiments.

Skills you gain in the lab and kitchen

  • Feeding a living culture on a fixed schedule
  • Working cleanly to prevent contamination
  • Reading a culture's health by smell and appearance
  • Keeping a feeding log over weeks
  • Reviving a weak culture with adjusted care

How it shows up in baking

A sourdough starter is a living mixed culture of yeast and bacteria that must be fed fresh flour and water on a schedule and stored at a steady temperature, or it weakens and mold moves in. Bakers discard a portion at each feeding exactly like subculturing, keeping the culture young and balanced. Both practices demand aseptic care, routine, and observation over weeks.

Recipes that demonstrate this technique

Each card shows exactly where the technique appears inside that recipe's method.

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