Stuck fermentation: a halt before the goal

The standard

Complete fermentation is reached when no fermentable sugar remains convertible; any interruption before that is a stall. What counts is the residual sugar relative to the fermentable share, not the time elapsed.

Criteria

• Fermentation ends although fermentable sugar remains
• Yeast activity declines without the fermentation goal being reached
• Causes lie in temperature, nutrient deficiency, alcohol or yeast health
• The state is measurable in the residual sugar, not in the duration

Distinction

Stuck fermentation ≠ intentional fermentation arrest: an arrest is brought about deliberately, a stall occurs unintended. Stuck fermentation ≠ alcoholic fermentation: fermentation is the process, the stall its unplanned interruption. Complete fermentation remains the reference point in both cases.