What Is Considered Leavening?

The Bible commands us not to have leavening for seven days during the Days of Unleavened Bread. But what exactly is leavening?

In preparing for the Days of Unleavened Bread, people often ask what constitutes the “leaven” that they need to remove from their property. God commands, “You shall remove leaven from your houses” (Exodus 12:15), but Scripture does not define “leaven.”

Rather than produce a list of items that “must go” or “can stay,” the Church has taught the scriptural instruction along with the principles contained therein, so that individuals would be able to exercise good judgment. We advise people to be cautious about accepting the wide variety of opinions, whether from Jewish traditions or even from within the Church of God community.

A basic definition of leavening

We look to history to learn what leaven was used in the past, and we look at modern baking practices for guidance. According to Smith’s Bible Dictionary, “Various substances were known to have fermenting qualities; but the ordinary leaven consisted of a lump of old dough in a high state of fermentation, which was mixed into the mass of dough prepared for baking.” Merriam-Webster’s Collegiate Dictionary defines leaven as follows: “1a: a substance (as yeast) used to produce fermentation in dough or a liquid; especially: SOURDOUGH b: a material (as baking powder) used to produce a gas that lightens dough or batter.”

However, some of these chemicals can have other uses besides leavening. Sodium bicarbonate (baking soda), for instance, can be used to control pH balance and for other medical issues. In such items as medicines, salt and antacids, it is commonly used as a binder, not as an agent to “puff up,” as is the case when it’s used for making bread or other baked products. Bottled water may have sodium bicarbonate added to enhance the taste and add minerals. When used in these ways, sodium bicarbonate and other such chemicals are clearly not acting as leavening agents. When chemicals that could be leavening agents—if they were used in conjunction with food—are used in other ways, they are not what God intended His people to put out to remember their affliction in Egypt.

This basic principle answers the host of questions about products that are not human food or bread/bread products: toothpaste, pet food, medicines, cat litter, salt, water, laundry detergents, antacids and fire extinguishers! None of these have to be put out.

What about brewer’s yeast, kefir and egg whites?

Live yeast is used in making beer. Therefore, it is sometimes called “brewer’s yeast.” However, the “brewer’s yeast” that appears on a food or health product label is “dead” (inactive, unable to leaven dough). This type of brewer’s yeast offers various health benefits, and it is often used as a dietary supplement. It is sometimes added to soups and other foods as a flavoring agent. Either it was harvested from the brewing process (from which it got its name, “brewer’s yeast”) and deactivated by heat or it was cultivated as inactive yeast for commercial use. The brewer’s yeast that is a food additive or a health supplement is not leaven.

Kefir is a fermented milk drink, but it is not leavened. The whey from kefir could be used as a leavening agent—just as the active leaven in unpasteurized beer could be used to make bread. Obviously, a believer should not use either to make bread during the Days of Unleavened Bread. However, the Church has not taught believers to avoid drinking these beverages during the Days of Unleavened Bread or to put them out before the festival merely because they could be used to leaven dough. Kefir and beer are beverages, not bread.

Some people question whether using egg whites to fluff up or lighten a baking batter “breaks the spirit of the law” and whether it is a type of leaven. There are other ways of mechanically adding air to dough. Historically, the Church of God has counseled that this is not leavening. We should remember that one characteristic of yeast and other leavening agents is that they spread their puffing-up quality until they change the nature of the entire batch of dough. That is not true of air added to dough by whipping. Active leaven makes an excellent symbol for sin, which spreads through human thoughts. Paul compared active leaven to sin with the phrase “a little leaven leavens the whole lump” (1 Corinthians 5:6).

Should we throw away our toasters?

About toasters or toaster ovens, the Church does not teach members to throw these away every year but to do the best they can to clean them. Some members clean such appliances by carefully spraying them with water—after unplugging them, of course! They find that by the time the festival is over, the toaster has dried thoroughly and is safe to plug in again. Another method of cleaning is simply to use the hand tools many vacuum cleaners have.

We should also consider the matter of personal conscience. Different believers can have different personal convictions about what constitutes leaven. We respect those convictions, even on matters about which the Church teaches differently; we do not tell people to act against their conscience. The Bible tells us that whatever we do that is not of faith is sin (Romans 14:23).

In conclusion, a Christian should look to the simplicity of Scripture: Put out leaven; do not eat leaven. As described, leaven means active yeast and chemical leavening agents, as well as human food products that were made with leaven. Keep it simple—and keep the Feast.

To learn more about this topic, read “What is Leaven and What Does it Picture?”