Leavened

Leavening is the action used to introduce bubbles into dough which when cooked, leaves a matrix of holes, often supported by proteins such as gluten that make the product airy and light.

There are many ways used to leaven doughs:

• Biological leaveners
  • beer (unpasteurised - live yeast)
  • buttermilk
  • ginger beer
  • kefir
  • sourdough starter
  • yeast
  • yogurt
• Chemical leaveners
  • baking powder
  • baking soda (a.k.a., sodium bicarbonate)
  • various bicarbonates
• Mechanical leaveners
  • Beating or whisking (particularly with egg-whites)
  • Creaming - mixing sugar crystals and solid fat
  • Introducing crushed ice and quickly cooking so the ice melts, leaving air-gaps

Unleavened

Unleavened, particularly when applied to bread, is when no leavening or rising agent is used. This normally means no yeast is used, due to religious taboo.