If you’re making a batch of fermented pickles, tannins are an essential ingredient to keeping them crisp and crunchy months later when you open the jar and take a bite.
Fermenting cucumbers is difficult because they have a high water content and they grow in the heat of summer which speeds the action of enzymes that decompose them.
In order to keep cucumbers from getting mushy, it is essential to add tannins to your jar of soon-to-be pickles. Tannins are astringent, naturally occuring phenol compounds that keep vegetables crisp.
Some sources of tannins:
- grape leaves
- horseradish leaves
- sour cherry leaves
- oak leaves
- black tea (1/8 cup per 1 liter of water)
- a green banana peel
Katz, Sandor Ellix. The Art of Fermentation: An In-depth Exploration of Essential Concepts and Processes From Around the World. Chelsea Green Pub., 2012.