The part of bread dough that makes
it rise. Sometimes it is used as a symbol
of bad influence.
A yeast is a tiny living fungus that makes bread rise and grow bigger when added to dough. In the Bible, it is also called leaven.
See Leaven.
Aquifer Open Bible Dictionary © 2026 Mission Mutual, an adaptation of the Tyndale Open Bible Dictionary © 2023 Tyndale House Publishers. Licensed under CC BY-SA 4.0.
A raising agent commonly used in bread. Bread that was required quickly was baked without yeast, as at the first Passover, commemorated annually in the Feast of Unleavened Bread. Although some non-meat offerings contained yeast, it could not be burned on the altar.
Unleavened bread was made without yeast
EXO 12:39 See also GEN 19:3; EXO 12:8–12:11, EXO 12:34; JDG 6:17–6:19; 1SA 28:24–28:25
The consumption of yeast was prohibited during the Feast of Unleavened Bread
EXO 12:14–12:15 See also EXO 12:17–12:20, EXO 13:3, EXO 13:6–13:7, EXO 23:15, EXO 23:18, EXO 34:18; LEV 23:6; NUM 28:17; DEU 16:1–16:4; EZK 45:21
Sacrifices burned on the altar were not to contain yeast
LEV 2:11 See also EXO 29:1–29:3, EXO 29:22–29:24, EXO 34:25; LEV 2:4–2:5, LEV 6:16–6:17, LEV 7:12–7:13, LEV 8:2–8:3, LEV 8:26, LEV 10:12; NUM 6:14–6:15, NUM 6:19
Some offerings contained yeast
Yeast as an image of the kingdom of God
MAT 13:33 parallel LUK 13:20–13:21
Metaphorical references to yeast as something evil
1CO 5:6–5:8 See also MAT 16:5–16:12 parallel MRK 8:14–8:21; LUK 12:1–12:3; GAL 5:2–5:12
Dictionary of Bible Themes © 1999 Martin H. Manser. Licensed under CC BY-SA 4.0.