What is Leaven?

(UnSplash Photo)

The Days of Unleavened Bread come in the Spring each year. For 2025, they begin at sunset on April 12th and run through sunset on April 19th.

The Bible teaches:’

18 In the first month, on the fourteenth day of the month at evening, you shall eat unleavened bread, until the twenty-first day of the month at evening. 19 For seven days no leaven shall be found in your houses, since whoever eats what is leavened, that same person shall be cut off from the congregation of Israel, whether he is a stranger or a native of the land. 20 You shall eat nothing leavened; in all your dwellings you shall eat unleavened bread. (Exodus 12:18-20)

Early Christians observed this time, as does the Continuing Church of God to this day.

The Bible teaches that, “no leaven shall be seen among you” (Deuteronomy 16:4), which is telling us:

There is leaven we do not see.
We need to remove all the leaven from our lives that we can, as well as symbolically removing all sins we know from our lives.

Jesus pointed to leaven is a symbol of false doctrine and hypocrisy:

6 Then Jesus said to them, “Take heed and beware of the leaven of the Pharisees and the Sadducees.”

7 And they reasoned among themselves, saying, “It is because we have taken no bread.”

8 But Jesus, being aware of it, said to them, “O you of little faith, why do you reason among yourselves because you have brought no bread? 9 Do you not yet understand, or remember the five loaves of the five thousand and how many baskets you took up? 10 Nor the seven loaves of the four thousand and how many large baskets you took up? 11 How is it you do not understand that I did not speak to you concerning bread? — but to beware of the leaven of the Pharisees and Sadducees.” 12 Then they understood that He did not tell them to beware of the leaven of bread, but of the doctrine of the Pharisees and Sadducees. (Matthew 16:6-12)

The Apostle Paul wrote to the Christians in Corinth:

7 Therefore purge out the old leaven, that you may be a new lump, since you truly are unleavened. For indeed Christ, our Passover, was sacrificed for us.

Notice clearly that the Gentile Corinthians would have been observing the Days of Unleavened Bread because the Apostle Paul stated “you truly are unleavened.”

The problem that the Corinthians had was that they were not unleavened spiritually. That is why Paul continued and told them to also spiritually be unleavened “with the unleavened bread of sincerity and truth.”

This also brings to mind the fact that God told the children of Israel to eliminate all the pagan groups in the promised land–but Israel did not, hence this caused Israelites to sin more.

We need to remove all sin we can see in our lives.

But most will not. Most think they are basically fine.

Jesus warned that most end time Christians think they are fine, but He told them that they needed to repent in Revelation 3:14-19.

Pride puffs people up.

Physical leaven puffs bread up.

But what is leaven anyway?

Here is some information from the old Worldwide Church of God:

Just what is leaven? Which foods are to be avoided during the Days of Unleavened Bread?

God uses leaven to typify sin (I Cor. 5:1-8). Sin puffs up just as physical leaven puffs up (verse 2). Unleavened bread is a type of an unleavened life.

To understand exactly what is included in the leaven we are to avoid during the Days of Unleavened Bread, let’s first notice some of the Hebrew words translated “leaven” in the Old Testament. Mechametz refers to leavening agents — substances used to puff up or produce fermentation, causing dough to rise. Yeast, bicarbonate of soda (baking soda) and baking powder are such substances.

Another Hebrew word rendered “leaven” is seh-ohd. This literally means “sourdough,” a naturally fermenting yeasty batter that was the most common leaven of the Israelites, and which is still often used to cause baked goods to rise and become light in texture.

These leavening agents cause foods to become chametz. This Hebrew word is translated “that which is leavened” in Exodus 12:19. It is also translated “leavened bread” in a number of places. It refers to all foods that leaven has caused to rise, including bread, cake, some crackers, certain cookies, some prepared cereals and pies. A few candies and other foods also make use of leavening agents. If you are in doubt about any product, check the list of ingredients on the wrapper.

Instead of eating leavened bread, we have the positive command to eat unleavened bread (Ex. 13:6). We may also eat unleavened pies and cereals together with all the meats, drinks, fruits and vegetables we normally consume.

Most stores carry a variety of unleavened breads. Always check the ingredients on the label to be sure. Or, you may enjoy making your own.

Some have asked about using egg whites in baking. Egg whites should not be used as a substitute for leaven, in a deliberate attempt to circumvent the spirit-of the law. On the other hand, beaten egg whites used in meringue on pies and other desserts do not constitute a leavening agent. They have not been used to puff up any product baked of flour or meal.

Others have noticed the term “yeast extracts” on the labels of certain foods and have wondered if they should be avoided. These are derivatives of yeast that cannot be used as leavening agents. It would therefore be permissible to use a product containing yeast extracts provided, of course, that it does not contain any actual leavening agent. Some people also buy brewer’s yeast from health food stores. This form of yeast is totally dead and should not therefore be considered as leaven. It should also be mentioned that cream of tartar, by itself, is not a leavening agent either.

Occasionally a question comes up about beer or other fermented drinks. There is nothing in the entirety of Scripture to indicate any restriction on the kind of beverages we consume during the Days of Unleavened Bread — no mention of these being the “Days of Unleavened Beverages.” The fact is that in all cases where the Days of Unleavened Bread are mentioned, the reference is always to the example set by the children of Israel when they came out of Egypt without any leaven in their dough (see Exodus 12:39). There is no reference to the invisible yeast or result of it in either beer, wine or other beverages.

Naturally fermented wine was customarily consumed by the Israelites at God’s festivals. If God had intended a ban on fermented beverages during the Days of Unleavened Bread, it would undoubtedly have been mentioned. In fact, such mention would have been necessary. Yet the command adds no more than is found in Exodus 13:6-7: “Seven days thou shalt eat unleavened bread… and there shall no leavened bread be seen with thee, neither shall there be leaven seen with thee in all thy quarters.”

If you are unsure about any particular food and unable to find the answer, you should refrain from eating it, “for whatsoever is not of faith is sin” (Rom. 14:23).

If partway through the Feast you find some leavened product that somehow escaped your scrutiny, put it off your property immediately. This is a type of those hidden sins that we don’t always discover upon conversion. We must keep on putting out sin (leaven) until the process is complete, as is signified by the very fact that there are seven — the complete number — Days of Unleavened Bread.

God intended the Days of Unleavened Bread to be a type to remind us that we are to be unleavening our lives spiritually by putting out the spiritual leaven of sin — not for seven days only, but throughout our entire lives! “Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth” (I Cor. 5:8). (Questions & Answers. Good News, March 1981)

Also, here is a list some may find to be helpful:

The Following is a List of Leavening Agents

Active Dried Yeast
Ammonium Carbonate – also known as “Hartshorn”
Ammonium Bicarbonate
Baker’s Ammonia
Baker’s Yeast
Baking Powder
Baking Soda
Bicarbonate of Soda
Dipotassium Carbonate
Disodium Phosphate
Monocalcium Phosphates (Ca(H2PO4)2)
Potassium Bicarbonate – also known as “Potash” or “Pearlash”)
Potassium Carbonate
Sodium Aluminum Phosphate
Sodium Bicarbonate – also known as “Saleratus”
Sourdough Starter Yeast
* Calcium Carbonate

* While Calcium Carbonate is normally not a leavening agent, it is considered to be one when it is in baked goods. Thus, while you can keep any calcium carbonate you have, any baked goods with it listed should be consumed or tossed out prior to the first day of unleavened bread.

All leavened items should be consumed or disposed of prior to the start of the First Day of Unleavened Bread each year and not be back in our homes until after the end of the Seventh Day of Unleavened Bread each year. And if we find any leaven in our homes during the Days of Unleavened Bread, we are to discard them immediately–just like we should immediately repent once we realize we have sinned in some manner.

Now, in this age of processed foods with various additives, perhaps it would be helpful to also list items that are NOT leavened agents that some may have wondered about.

What are not leavening agents?

The Following Are “Not” Leavening Agents

Autolyzed Yeast
Brewer’s Yeast
Corn Starch
Egg Whites
Polysorbate 60
Potassium Bitartrate (Cream of Tartar)
Sorbitan Monosterate
Tartrate powder
Torula Yeast
Yeast Extract

Hopefully, this will help those who have questions about which items should be gone prior to the first Day of Unleavened Bread each year.

Physically, leavening agents “puff up” grain containing products and make them look larger than they would be otherwise.

People often want to look more influential, etc. than they really are.

Notice what God really wants:

8 He has shown you, O man, what is good;
And what does the Lord require of you
But to do justly,
To love mercy,
And to walk humbly with your God? (Micah 6:8)

Satan’s problem was that he refused to walk humbly. He was the anointed cherub (Ezekiel 28:14–he had it all–but his pride got in the way (cf. Ezekiel 28:17). Humans often let their pride get in the way (Proverbs 29:33–and pride puffs people up (cf. 1 Timothy 3:6). Most will not do what God says as their pride and human reasoning, influenced by Satan, gets in the way.

Consider also:

18 Pride goes before destruction,
And a haughty spirit before a fall.
19 Better to be of a humble spirit with the lowly,
Than to divide the spoil with the proud.

20 He who heeds the word wisely will find good,
And whoever trusts in the Lord, happy is he. (Proverbs 16:18-20)

Do you really trust God and not yourself? Can you humble yourself and really change your faults? You can with Jesus’ help (Philippians 4:13).

Do not be among those to whom God says:

3 The pride of your heart has deceived you, (Obadiah 3)

Humble yourself and change.

23 A man’s pride will bring him low, But the humble in spirit will retain honor. (Proverbs 29:23)

12 Before destruction the heart of a man is haughty, And before honor is humility. (Proverbs 18:12)

33 The fear of the Lord is the instruction of wisdom, And before honor is humility. (Proverbs 15:33)

God wants you to forsake pride, accept His teachings, be humble, and THEN He will grant honor. Many do not have the faith to truly humble themselves as the above suggests:

8 Nevertheless, when the Son of Man comes, will He really find faith on the earth? (Luke 18:8)

Many claim to believe in Jesus, but are unwilling to truly humble themselves before God–such humility takes faith.

Consider also that the Bible teaches:

15 On the first day you shall remove leaven from your houses. (Exodus 12:15)

Those who attempt to obey God follow this and remove all leavened breads, crackers, etc. from their houses, clean out their toasters, and otherwise remove physical leaven from their lives just prior to the start of the Days of Unleavened Bread each year. Most people do not have the humility to do this, and many that do seem to let pride get in the way of removing their own sins.

We are always to be examining ourselves by the standards in the word of God.

Searching for, and removing leaven, before the Days of Unleavened Bread can help us to see that just like we may find leaven in places we never expected, we may have sins and pride in areas we also had not considered.

Some items of possibly related interest may include the following:

Leaven, Sin, and Why to Not Sin What is leaven? What is sin? Why is sin so bad? Can sin effect your eternity? Here is a link to a related sermon: Leaven, Sin, and Purpose.
Christians: Ambassadors for the Kingdom of God, Biblical instructions on living as a Christian This is a scripture-filled booklet for those wishing to live as a real Christian. A related sermon is also available: Christians are Ambassadors for the Kingdom of God. Here is a video in Spanish: ¿Qué es un verdadero cristiano?
Living as a Christian: How and Why? In what ways do Christians live differently than others. What about praying, fasting, tithing, holy days, and the world? There are also two YouTube video related to this: Living as a Christian: How and Why? and Living as a Christian: Pure Milk of the Word.
Should You Keep God’s Holy Days or Demonic Holidays? This is a free pdf booklet explaining what the Bible and history shows about God’s Holy Days and popular holidays. Two related sermons would be Which Spring Days should Christians observe? and Fall Holy Days for Christians.
Unleavened Bread, Jesus, and the New Testament? What happened to Jesus during the Days of Unleavened Bread? Do the Days of Unleavened Bread have any Christian meaning? Are there passages in the New Testament supporting not only keeping the Days of Unleavened Bread, but the meaning behind them? Here is a link to a related sermon: Unleavened Bread, Jesus, and the Apostles.
Holy Day Calendar This is a listing of the biblical holy days through 2033, with their Roman calendar dates. They are really hard to observe if you do not know when they occur ? In the Spanish/Español/Castellano language: Calendario de los Días Santos. In Mandarin Chinese: 何日是神的圣日？这里是一份神的圣日日历从2013年至2024年。.