In this article we will examine the meaning of leavening. For the last 20 years, this ministry has viewed leavening as an item that simply contained a leavening agent, e.g., yeast or baking soda. However, after a recent in-depth study, we have discovered that the concept of leavening is more complex.

The catalyst that motivated this study was Leviticus 23:13. “And the meat offering thereof shall be two tenth deals of fine flour mingled with oil, an offering made by fire unto Yahweh for a sweet savour: and the drink offering thereof shall be of wine, the fourth part of an hin.”

We see here a reference to the firstfruits offerings during the Feast of Unleavened Bread. One item that is prohibited during this Feast is leavening.

Historically we’ve defined leavening as an item that simply contained a leavening agent. From this passage, though, we find a problem with this definition: the mention of wine. As most may know, wine is produced with yeast, a leavening agent. And for this reason it’s also been our position that wine and other alcohol must be removed during Unleavened Bread. But as we see in this passage, wine was used in an offering during the Feast of Unleavened Bread.

Some may wonder, is the wine mentioned here really alcohol? Maybe it’s something closer to grape juice. The word wine comes from the Hebrew yayin, which Strong’s defines as, “wine (as fermented); by implication, intoxication.” The Brown Driver Briggs Hebrew Lexicon also defines this word as, “wine.” Based on Strong’s and BDB, we know that this word refers to fermented wine.

So how do we reconcile what we’ve always believed with what we find here? The answer is we can’t. We can’t reconcile our previous definition of leavening with the fact that wine was the drink offering commanded during the Feast of Unleavened Bread, which is why we took the time to re-evaluate this belief.

Going back to the Hebrew, we reviewed every instance of where leavening is used in Scripture. This involved every instance of the Hebrew words seor and chamets, the words used for leavening in the Tanakh or the Old Testament. To understand leavening, we MUST understand the meaning of these Hebrew words.

We find our first example in Exodus 12:15: “Seven days shall ye eat unleavened bread; even the first day ye shall put away leaven out of your houses: for whosoever eateth leavened bread from the first day until the seventh day, that soul shall be cut off from Israel.”

This passage refers to the Feast of Unleavened Bread during which time we’re to put away the leaven or seor from our homes and abstain from eating leavened bread or chamets. I want to point out that it explicitly mentions eating; nothing is said about drinking. As we’ll see from other instances, chamets is always connected to eating. Interestingly, this time is called the Feast of Unleavened Bread, not the Feast of Unleavened Drink.

Meaning of Seor

Let’s focus now on the meaning of seor. According to Strong’s, seor is defined as, “barm or yeast-cake (as swelling by fermentation).” According to the Merriam-Webster Dictionary, barm is defined as “yeast formed on fermenting malt liquors.” The yeast cake mentioned here is a reference to a sourdough starter, which is how Israel would leaven their dough to make leavened bread or chamets.

Continuing to look at the meaning of seor, we discover that the Fausset’s Bible Dictionary defines this word as, “A lump of old dough in high fermentation. Because making it, and leavening bread with it, took time, unleavened bread was used in sudden emergencies (Gen 18:6; 19:3). It was forbidden in all offerings to [Yahweh] by fire (Lev 2:11; 7:12).”

We see here that seor refers to an old piece of dough that is highly fermented, which is what we call a sourdough or a starter dough. It’s a piece of dough that is allowed to ferment to the point of becoming sour or acidic and then used to leaven another piece of dough. This dough contains both grain and a leavening agent. For Israel, the leavening agent would have been wild yeast. Therefore, seor must include grain plus a leavening agent and not a leavening agent alone.

When speaking of yeast and starter dough, a few facts to consider are:

1) wild yeast is all around us and even within us; 2) a starter is formed when the yeast breaks down the starch in the flour into sugar, producing carbon dioxide; and, 3) it’s the carbon dioxide that causes the bread to puff up or to rise. The rising was the focus of seor and chamets.

In fact, the word “leaven” comes from the Latin verb levare, meaning, “to raise.” Again, what allows for this to happen is the starter dough, i.e., the dough that is in high fermentation or that contains a high concentration of yeast. Therefore, when we speak about seor, especially from a biblical standpoint, we are speaking about a sourdough starter, which is how Israel leavened their dough.

The New Unger’s Bible Dictionary refers to seor as a small portion of dough that is highly fermented and turning acidic or sour. This was used to leaven and produce leavened bread or chamets. “The Heb. term se’or occurs only five times in Scripture, in four of which (Ex 12:15, 19; 13:7; Lev 2:1-11) it is translated ‘leaven’ and in the fifth (Deut 16:3) ‘leavened bread.’

The NIV translates ‘yeast’ in each of these references. This probably denotes the small portion of dough left from the preceding baking that had fermented and turned acidic. Its distinctive meaning is fermented or leavened mass.”

Another source, Nelson’s Illustrated Bible Dictionary, gives the following definition: “A substance used to produce fermentation in dough and make it rise (Ex 12:15, 19-20). In Bible times leaven was usually a piece of fermented dough retained from a previous baking that was placed in the new dough to cause it to rise.”

From here we see that seor refers to a piece of old dough in high fermentation that would then be used to leaven new dough, which is what we would call a sourdough starter.

A similar explanation is found in the International Standard Bible Encyclopaedia: “In bread baking.-The form of leaven used in bread-making and the method of using it were simple and definite. The ‘leaven’ consisted always, so far as the evidence goes, of a piece of fermented dough kept over from a former baking. There is no trace of the use of other sorts of leaven, such as the lees of wine or those mentioned by Pliny (NH, wviii.26). The lump of dough thus preserved was either dissolved in water in the kneading-trough before the flour was added, or was ‘hid’ in the flour (the King James Version ‘meal’) and kneaded along with it, as was the case mentioned in the parable (Matt 13:33). The bread thus made was known as ‘leavened,’ as distinguished from ‘unleavened’ bread (Ex 12:15, etc.)”

Again we see that leavening or seor refers to a piece of leavened dough from a previous baking, which would then be used to leaven a new loaf.

According to this source, this could have been done in two different ways. The first process would be to dissolve the starter within the kneading-trough before the flour was added. The other method was simply to take the starter and place or hide it within a new dough. Either of these two methods would leaven a new piece of dough, causing it to rise. This was done using the starter or this highly fermented, acidic piece of dough.

For good measure, let’s consider one more reference, from the Cyclopedia of Biblical, Theological, and Ecclesiastical Literature. “‘Seir’ occurs only five times in the Scriptures, in four of which (Ex 12:15, 19; Ex 13:7; Le 2:11) it is rendered ‘leaven,’ and in the fifth (De 16:4) ‘leavened bread.’ It seems to have denoted originally the remnant of dough left on the preceding baking which had fermented and turned acid.”

This source once more confirms the meaning of seor, a portion of leavened dough from a previous baking that has turned acidic or sour.

In summation, we learn that seor is a piece of dough that contains flour and yeast, is highly acidic, and is used as a sourdough starter. Also, by the existence of wine during the Feast of Unleavened Bread, we see that a leavening agent alone, e.g., yeast or baking soda, would NOT be considered seor.

 

What is Chamets?

Let’s now review the meaning of chamets. Strong’s states, “ferment, (figuratively) extortion: -leaven, leavened (bread).” The Brown Driver & Briggs Hebrew Lexicon explains it as: “…that which is leavened…forbidden at Passover Exodus…in all sacrifices…exceptions are of peace-offering and the wave loaves.

Biblically, we see that chamets refers to leavened bread. We also know that it’s forbidden during the Passover or the Feast of Unleavened Bread, along with all sacrifices, except for the peace offering and the wave loaves offered during the Feast of Weeks or Shavuot.

Here’s how the Cyclopedia of Biblical, Theological, and Ecclesiastical Literature defines leavening: “‘chamets’ ought not to be rendered ‘leaven,’ but leavened bread… In Ex 13:7, both seor’ and chamets’ occur together, and are evidently distinct: ‘Unleavened bread (matstsah’) shall be eaten during the seven days, and there shall not be seen with thee the fermented bread (chamets’), and there shall not be seen with thee leavened bread (seor’) in all thy borders.”

We see that chamets is not simply leavening but is leavened bread. In other words, it is the leavened product produced from the seor. Again, the primary example of chamets from the Bible is leavened bread. There are no other examples for chamets, but for leavened bread, whether eaten or used in sacrifice. When we think of seor, we should think of a sourdough starter, and when we think of chamets, we should think of a leavened product produced by a sourdough starter or an alternative leavening agent.

 

The Jewish Perspective

Let’s consider now how the Jews understand leavening.

According to oukosher.org, “If one of the five grains – wheat, barley, rye, oats and spelt – sits in water for more than 18 minutes it becomes chametz, and one may not eat, derive benefit from or own it on Pesach.”

Kashrut Division of the London Beth Din, kosher.org.uk, states, “Chametz is formed when dough made from wheat, barley, rye, oats or spelt is allowed to ferment (or rise). The time in which fermentation takes place is deemed to be 18 minutes.”

As the last example, chabad.org verifies that “chametz (also spelled ‘hametz’ or ‘chometz’) is any food product made from wheat, barley, rye, oats or spelt that has come into contact with water and been allowed to ferment and ‘rise.’”

We see that chamets is any food product that is produced from grain that has come in contact with water and allowed to ferment or rise. So based on the Jewish understanding of leavening, we find that four things are needed for something to be considered chamets:

1) It needs to contain grain, e.g., wheat, barley, rye, oats or spelt;

2) It needs water;

3) It needs access to a leavening agent, which is around us in the form of wild yeast; and,

4) It needs time to leaven or to rise.

According to many Jews, the time it takes for a piece of dough to become leavened is 18 minutes. With this in mind, if we took flour, added water, and then allowed that dough to ferment with the natural yeast within the air for 18 minutes. According to many Jews, we would have chamets.

Because chamets requires all these items, a leavening agent alone is not considered chamets or seor. For those who were part of the initial study, this was the bombshell that changed the trajectory of what we would come to understand about leavening. Again, it was always our belief that a leavening agent alone was considered seor or chamets, but when we understand these words from a biblical standpoint, there’s more to it. In this case, we know that yeast or a chemical leavening agent alone is not considered chamets.

Wikipedia concurs: “Chametz is a product that is both made from one of five types of grain and has been combined with water and left to stand raw for longer than eighteen minutes (according to most opinions) and becomes leavened … Leavening agents, such as yeast or baking soda, are not themselves chametz. Rather, it is the fermented grains. Thus yeast may be used in making wine.”

From this source, we again see that chamets is when grain is combined with water and allowed to become leavened. Remember, from a biblical standpoint, seor is a sourdough starter, and chamets is a leavening product made from seor.

 

Examples of Seor and Chamets

Let’s now review where soer and chamets are used within Scripture. From the Torah we find the following passages containing the word seor.

Exodus 12:19 – “Seven days shall there be no leaven found in your houses: for whosoever eateth that which is leavened, even that soul shall be cut off from the congregation of Israel, whether he be a stranger, or born in the land.” All seor must be removed from our homes during the seven days of Unleavened Bread.

Exodus 13:7 – “Unleavened bread shall be eaten seven days; and there shall no leavened bread be seen with thee, neither shall there be leaven seen with thee in all thy quarters.” All seor must be removed from our quarters, Heb. gebul, referring to a person’s boundary or territory.

Leviticus 2:11 – “No meat offering, which ye shall bring unto Yahweh, shall be made with leaven: for ye shall burn no leaven, nor any honey, in any offering of Yahweh made by fire.” No meat or grain offering was to be made with seor or a sourdough starter. THIS IS IMPORTANT – it shows that seor was the initial starter that was used to leaven chamets.

Deuteronomy 16:4 – “And there shall be no leavened bread seen with thee in all thy coast seven days; neither shall there any thing of the flesh, which thou sacrificedst the first day at even, remain all night until the morning.” No seor was to be seen within a person’s coast, Heb. gebul, referring to a person’s boundary or territory.

Let’s now look at the examples for chamets, which is found 13 times in the Old Testament, 12 within the Torah and once within the Nevi’im, e.g., prophets.

Exodus 12:19 – “Seven days shall there be no leaven found in your houses: for whosoever eateth that which is leavened, even that soul shall be cut off from the congregation of Israel, whether he be a stranger, or born in the land.” The command is not to eat chamets during the seven days of Unleavened Bread. The penalty for ignoring this command was to be cut off from the congregation. It’s crucial that we do our very best to abstain from eating leavened products or chamets during the Feast of Unleavened Bread.

Before moving on, I want to emphasize that the command here is eating and not drinking. And the reason for this is simple – chamets is leavened bread, not leavened drink.

Exodus 12:20 – “Ye shall eat nothing leavened; in all your habitations shall ye eat unleavened bread.” As we saw in verse 19 we see here, that we’re to abstain from eating chamets or anything leavened during this Feast. And again, I point out that the command is of eating, nothing is said about drinking. For those wondering, there is a Hebrew word for drinking, it is shathah, but we don’t find that word in relation to seor or chamets.

Exodus 13:3 – “And Moses said unto the people, remember this day, in which ye came out from Egypt, out of the house of bondage; for by strength of hand Yahweh brought you out from this place: there shall no leavened bread be eaten.” As we’ve seen previously, Yahweh commands us here not to eat chamets or leavened bread during this Feast.

Exodus 13:7 – “Unleavened bread shall be eaten seven days; and there shall no leavened bread be seen with thee, neither shall there be leaven seen with thee in all thy quarters.” There are several items to consider here: we’re to eat unleavened bread, i.e., matstsah’, for all seven days of this Feast. So, in contrast of removing and abstaining from leavening, we find that we’re to eat unleavened bread for all seven days of this Feast.

As we know from the New Testament, unleavened bread symbolizes sincerity and truth. Understand that there’s a spiritual lesson to be learned throughout this Feast. This passage also relates that no chamets or seor should be seen within our quarters or boundaries.

Exodus 23:18 – “Thou shalt not offer the blood of my sacrifice with leavened bread; neither shall the fat of my sacrifice remain until the morning.” As we saw from the BDB, we also find here that no leavened bread or chamets was to be included within the offerings. The only exception was the peace, or fellowship offering along with the two loaves offered during the Feast of Weeks.

Exodus 23:25 – “And ye shall serve Yahweh your Elohim, and he shall bless thy bread, and thy water; and I will take sickness away from the midst of thee.”

Leviticus 2:11 – “No meat offering, which ye shall bring unto Yahweh, shall be made with leaven: for ye shall burn no leaven, nor any honey, in any offering of Yahweh made by fire.” A better name for the meat offerings is a grain offering and as before, leavening, whether chamets or seor, was not allowed within this offering. We also see the mention of honey and because of this, some ask if we should be removing honey during the Feast of Unleavened Bread. While honey can be used to speed up the leavening process, honey of its own is NOT considered seor or chamets. For this reason, there’s no need to remove honey during this Feast.

Leviticus 6:17 – “It shall not be baken with leaven. I have given it unto them for their portion of my offerings made by fire; it is most holy, as is the sin offering, and as the trespass offering.” Two specific offerings are mentioned here – the sin offering for unintentional sins and the trespass offering, which was for intentional sins. Notice that if a person brought a cake or grain offering, it had to be without leavening or chamets. This offering was a food product that was baked.

Leviticus 7:13 – “Besides the cakes, he shall offer for his offering leavened bread with the sacrifice of thanksgiving of his peace offerings.” Unlike the sin and trespass offerings, we find that leavening was to be used during the fellowship or peace offering. The peace offering was a show of desire to fellowship with Yahweh and for this reason, it was treated differently.

Leviticus 23:17 – “Ye shall bring out of your habitations two wave loaves of two tenth deals: they shall be of fine flour; they shall be baken with leaven; they are the firstfruits unto Yahweh.” Again, we see that leavening or chamets was to be used within the wave loaves offered during the Feast of Weeks or Shavuot. As was seen here and in the previous example, leavening or chamets is not always negative. We know this because it was commanded to be used in the peace offering and the wave loaves offering to Yahweh.

Deuteronomy 16:3 – “Thou shalt eat no leavened bread with it; seven days shalt thou eat unleavened bread therewith, even the bread of affliction; for thou camest forth out of the land of Egypt in haste: that thou mayest remember the day when thou camest forth out of the land of Egypt all the days of thy life.” This passage is referring to the Feast of Unleavened Bread. As we’ve already seen from many other examples, during these seven days we’re to abstain from eating leavened bread or chamets.

Amos 4:5 – “And offer a sacrifice of thanksgiving with leaven, and proclaim and publish the free offerings: for this liketh you, O ye children of Israel, saith my Sovereign Yahweh.” We find here another reference to the fellowship or peace offering in which leavening or chamets was to be used.

Let’s review what we’ve learned thus far about seor and chamets:

• In the Old Testament, the word seor is found five times and the word chamets is seen 13 times, referring to the sourdough starter and leavened bread, respectively.
• During the Feast of Unleavened Bread, we’re commanded to remove all seor and chamets from our homes and boundaries.
• During this Feast, we’re commanded to eat unleavened bread and abstain from eating leavening or leavened bread in the form of seor or chamets, emphasizing the focus is on eating and not drinking.
• Except for the peace offering and the two wave loaves offered during Shavuot, no seor or chamets was to be used in a sacrifice or offering.

 

Defining Seor and Chamets

What do you suppose ancient Israelites would show us if we asked for examples of seor and chamets? More than likely they would bring us a sourdough starter for seor and a loaf of leavened bread for chamets.

Based on this, we offer the following definitions for seor and chamets:

Seor: A piece of highly fermented or acidic dough or any other grain-derived leavening product that might be used to leaven dough, much like our own sourdough starter.

Chemets: Any grain derived food product that has been leavened by seor, i.e., a leavening agent, whether that be natural or chemical. The primary example would be leavened bread, but it would also include items that may not resemble bread but contain both grain and a leavening agent.

So again, any food product containing grain, wheat, barley, spelt, rye or oats, along with a leavening agent, would be considered chamets. This is why we must take stock of the food items we have within our homes before the Feast of Unleavened Bread and remove anything that would be considered seor or chamets.

We have only referenced leavening agents until now, but have not provided a list of such agents. Below is a list of leavening agents we have identified over the years.

• Yeast
• Baker’s yeast
• Active dried yeast
• Baking powder
• Baking soda
• Cream of tartar (potassium bitartrate)
• Ammonium carbonate
• Ammonium bicarbonate
• Potassium carbonate
• Potassium bicarbonate
• Dipotassium carbonate

Remember that these leavening agents alone are NOT considered seor or chamets. For this reason, there’s no need to remove these leavening agents from our homes during the Feast of Unleavened Bread.

However, there is one caveat. Based on our research, some yeast packets would be considered seor due to the way they are manufactured. Some companies will produce a yeast cake with grain and then disaggregate that yeast cake into the yeast we find within many yeast packets.

This seems to be especially common with organic yeast packets. Because of this, we encourage you to remove your yeast packets during the Feast of Unleavened Bread.

But for the other items in the above list, there’s no need to remove them unless you are convicted of doing so, which is certainly acceptable.

 

What May Remain?

Beyond defining leavening, we must address those items that may remain during the Feast of Unleavened Bread that we previously disallowed. Since leavening agents alone are not considered seor or chamets, there is no need to remove leavening agents that cannot be used as a starter in their current form, e.g., baking soda and baking powder.

In addition to leavening agents, there is also no need to remove alcohol unless there’s evidence that it can be used as a starter. The following alcohols contain no yeast in their final form and therefore would not be considered seor: vodka, gin, tequila, Irish whiskey, bourbon, schnapps, most wine, and many commercial beers.

Even though many alcoholic beverages contain grain and a leavening agent, e.g., yeast, in their original form, the leavening agent is purged or made inert in its final form. For this reason, they are unable to be used as seor or a starter.

In our research we contacted several brewers and verified that most commercial beers either remove or kill any excess yeast; some exceptions, though, include Pale Ale, Porter, and Stout. Therefore, if you choose to keep commercial beers, we suggest that you confirm with the manufacturer that the yeast has been removed or made inert.

In our investigation, we sent the following question to several breweries: “Can you verify if any of your beers contain live or active yeast that could be used as a starter to make bread without the assistance of any additional leavening agents?”

We received the following replies:

“I can tell you that almost all beer, except for draught beer, is pasteurized. This process enables the brewer to kill traces of live yeast or other organisms which helps the beer stay fresh longer,” Anheuser-Busch.

“Almost all of the yeast used in the brewing process is filtered out of the beer prior to packaging,”

Molson Coors Beverage Company.

“The yeast used to make our beers is filtered out before bottling. If you would like yeast for bread or other means, we recommend buying yeast itself,” Samuel Adams.

“Our bottle-conditioned beers will have live yeast sitting at the bottom of the bottle. Bottle-conditioned beers include: Pale Ale, Porter, Stout, Celebration, and Bigfoot. There are about a couple thousand cells at the bottom of a can or bottle and will need to be propagated to be used for making bread. Yeast for bread and our ale yeast are a little different. You may have to use a bit more ale yeast than the recipe calls for or use additional leavening agents,” Sierra Nevada Brewing Company.

Also, as we see from Scripture, chamets is a food item. Therefore, by definition, alcohol would not be considered chamets and since most beer cannot be used as a starter, it would not be considered seor.

In addition to alcohol, since the Feast of Unleavened Bread focuses on food items we consume, there is no reason to remove non-food items with a leavening agent, e.g., baking soda toothpaste.

What About Grain Substitutes?

The last issue to address is grain substitutes. Examples of this includes quinoa, rice, almonds (and other nuts), coconut, tapioca, or sorghum. Many Jews use grain substitutes with a leavening agent to make cakes and other items during the Feast of Unleavened Bread. Even though grain substitutes are technically not grain, we believe that using such products combined with a leavening agent to make bread or pastries violates the command of abstaining from leavened bread during the Feast of Unleavened Bread. The main point of this Feast is to remove and abstain from leavened bread or that which puffs up.

 

In Summary

Let’s now summarize what we have learned:

• Wine was used during the Feast of Unleavened Bread in the form of an offering. This shows that a leavening agent on its own is NOT biblically considered leavening.
•   The two words for leavening or leavened bread within Hebrew are seor and chamets.
•   From a biblical standpoint, seor refers to a piece of highly fermented or acidic dough or any other grain-derived leavened product that might be used to leaven dough, much like our own sourdough starter.
•   Chamets would be any grain-derived food product that has been leavened by seor or a leavening agent, whether natural or chemical.
• Except for yeast packets, a leavening agent alone is NOT considered seor or chamets.
• Since most alcohol does not contain active yeast and cannot be used as a sourdough starter, i.e., seor, and would not meet the definition of chamets, it can remain during the Feast of Unleavened Bread.

I hope that this information has helped you better understand the biblical definition of leavening. We encourage you to prove all things from Yahweh’s Word as we are all obligated to do