Passover and Leaven

matzot-350x200These days one hears much about the "Holiday" of Passover and even we Karaites refer to it often. But in the Hebrew Bible there is no such holiday! In the Tanach "Passover" is the name of a sacrifice, while the holiday is called Chag HaMatzot ("Feast of Unleavened Bread"). Thus in the verse: "Draw out and take a lamb according to your families, and slaughter (KJV: kill) the passover." (Exodus 12:21). In this verse the "Passover" is the lamb that is to be sacrificed by slaughtering and eating it. Similarly in Exodus 12:26-27:

"...when your children shall say to you, What mean ye by this service? And you shall say, It is the sacrifice of Yehovah's passover"

The service of slaughtering the lamb and eating it is called "the sacrifice of Yehovah's passover". This is also the meaning of Passover in the verse: "In the fourteenth day of the first month between the two evenings is Yehovah's passover" (Leviticus 23:5). And again in Deuteronomy 16,1: "Observe the month of the Aviv, and perform the passover unto Yehovah your God". To "perform" or "keep" the Passover (in Hebrew literally "do the Passover") means to bring the Passover sacrifice and eat it. It is only in post-Biblical times that the word Passover took on the new meaning of referring to the Holiday on which the sacrifice was eaten and not to the sacrifice itself. Today we often hear of the "Passover Holiday" and "Chag Ha-Pessach" both of which are post-Biblical inventions. In the Tanach the Holiday is called Chag HaMatzot which means: "Feast of Unleavened Bread".

What is Leaven?

There is a centuries-old debate among the Karaites themselves about the definition of Hametz (leaven). According to the first opinion Hametz is the process of leavening that occurs to certain grains when they are mixed with water. The test to identify what types of grain can become Hametz is to take the flour of that grain, mix it with water, and leave it for a few hours. If the dough rises, that grain is subject to becoming Hametz (leaven). On the other hand, if the dough spoils, then that grain or plant is not leaven-able and it can be freely used and cooked on Passover.

This seems rather obvious but in the Middle Ages the question arose of whether lentil-flour was permissible on Passover. While lentils are not grains, their flour looks much like wheat-flour. The Rabbanites too puzzled over this issue and to this day Sephardic Rabbanites eat lentils on Passover while Ashkenazic Rabbanites do not. Rather than accept arbitrary rulings the Karaite sages sat down and performed experiments. They concluded that the flour of lentils does not rise but spoils and therefore lentils in all its forms are permissible on Passover. The same with rice which is also permissible in all its forms on Passover. Adherents of this view include most of the medieval Karaite sages including Aharon ben Eliyah and Elijah Baschyatchi (see below) as well as the present author.

Not all Karaites agree with this definition. The second school of thought argues that Hametz is not strictly speaking "leavening" but something like "fermentation". They point out that in biblical Hebrew vinegar is called "Hometz Yayin" meaning "leavened-wine" (others translate: "soured wine"). This is used as proof that Hametz refers not only to the leavening of grains but any fermentation or souring process. Based on this reasoning, they forbid the consumption of anything fermented. Included in their list of forbidden foods on Passover are all forms of alcohol, and all milk products such as yogurts and cheeses. Some, although not all, include lentils and rice in this list of forbidden items. This school also considers wine to be Hametz, which is somewhat surprising given that vinegar is called "leavened-wine" (implying that the difference between wine and vinegar is that the latter is leavened but the former is not!). Adherents of this view include the medieval Karaite sage Samuel al-Maghrebi.

The following are excerpts from the writings of some medieval Karaite sages on Hametz:

"and the sage our teacher Yosef Kirkisani said... only the five types of grain can be made into Hametz, namely wheat, spelt, barley, oats, and rye. And the sage was correct because whatever experimentation shows to leaven can be used for Matzah, but the flour of the other 'seeds' do not leaven. For example, [the flour of] millet, rice, beans, lentils, and peas do not leaven but spoil [lit. 'stink']." [Aharon ben Eliyahu (14th Century), Gan Eden, pp.45d-46a].

"The sage Yosef Kirkisani said that only the five types of grain can be made into Hametz, namely, wheat, spelt, barley, oats, and rye. It has also been said that if experimentation shows that a thing can become leaven then it can be used to make Matzah. However, all the other 'seeds' such as bean, lentil, pea, millet, and rice flours do not leaven but spoil [lit. stink]. And the sage our teacher Aharon (author of Etz Hayyim) said that all of these matters can become known through experimentation and he has spoken well for millet flour if left with water for a number of days does leaven. Therefore, in truth, there are six types of grain that can leaven and from which Matzah can be made: the aforementioned five as well as millet. And if Hametz is made from any of these it must be destroyed... and so too any alcohol made from the five types of grain [e.g. beer] or from millet. But some of the fools in our times who pretend to be wise do not eat anything that ferments based on the verse 'no leaven shall you eat' such as fermented milk [i.e. yogurt, etc.] and fruits soaked in water; they also refrain from eating beans and rice and any type of 'seed' and this is because of their foolishness and their lack of knowledge..." [Elijah Baschyatchi (15th century), Aderet Eliyahu, Ramla 1966, pp.133-134]

See also the treatise of Samuel al-Maghrebi in Karaite Anthology.

Have a happy and Kosher Chag HaMatzot!

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Torah Pearls - Passover Special
Passover and Leaven
When was the Passover Sacrifice Brought
Was the Last Supper a Passover Seder
How Long were the Israelites in Egypt
From Slavery to Freedom
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  • Conchita says:

    When is Passover this year

  • JCLincoln says:

    Is it … or should it be the resultant ‘action of rising’, or should it be considered the spread of the “culture” throughout the entire medium that should be regarded as the unwanted trait?
    Certainly, an argument can be made along the lines of ‘pride puffs up’, so the considering of oneself as greater than one really is, gives credence to the ‘action of rising’ conclusion.
    But the observation that when a bacteria is introduced into a medium, unless checked somehow, the bacteria will spread throughout the entire medium, gives a better description of how sin proliferates simply upon the initial introduction ….. seeming to have a life of its own. Thus “sin” can simply wait at the door, ready to pounce.

  • Dennis Martin says:

    Always enlightening to read/hear your Biblical interpretations. Blessings.

  • Neville says:

    It seems pretty clear to me that a lot of the “leaven” that tradition says should be removed from the house (or borders) is not leaven at all. I would appreciate some thoughtful responses to my thinking below.


    Although the Exodus story does not spell out a definition of leaven, when we look to other scripture for understanding then we should equate “leaven” with a corrupting agent.

    Leaven is not the process of rotting or oxidation. It is not even the process of carbonation. Leaven is a thing, not a process. The thing corrupts in a particular way that we know as yeast fermentation (bread, wine, etc.). Live yeast organisms do this. Dead ones do not.

    Heat kills yeast. Try activating dormant powdered yeast with water that is too hot, and the yeast will die. You cannot leaven a lump of bread dough by throwing in a hunk of cooked bread. “Leavened bread” is made to rise by the fermentation process of the leaven (yeast), but after cooking the leaven is gone, dead, kaput.

    Baking powder and baking soda do not corrupt. They do not cause fermentation. They are basically fake ways of getting one of the results of true leavening: gas bubbles trapped in the dough to make it fluffy. Mixing the baking soda/powder with anything acidic (even milk or honey) will cause the CO2 to be released. It is essentially the same thing as injecting CO2 into Coca-Cola syrup to make the carbonated fountain drink.

    It is common for baking soda and baking powder to be referred to as “leavening agents” but they are, at best, pretenders. They are not leaven.

    Regarding Chag haMatzot, scripture says we are to do 2 specific things regarding leaven: 1) for 7 days don’t eat bread made with leaven, and 2) remove leaven from our houses (or borders).

    Sweeping up bread crumbs from out of the cabinet or under the table does not remove leaven.
    Throwing out a half-finished loaf of bread does not remove leaven.
    Throwing out your Mountain Dew does not remove leaven.
    Throwing out a box of baking soda does not remove leaven.
    Throwing out the dried-up pieces of Big Mac bun from your car’s floor mat does not remove leaven.
    [ Those things above are all fences, and while the exercise is not without spiritual merit, it is nevertheless going beyond the instruction of scripture. As long as we understand that, and don’t confuse fences with actual instructions, then I don’t think there is a problem. ]
    Throwing out / destroying your yeast or bread starter DOES destroy leaven.

    So, based on the above, separating out tradition and fences from the simple admonitions of scripture, I would say we must do the following:
    1) Get rid of your yeast. Get rid of anything in which you know yeast is growing (like sourdough starter).
    2) If you have leavened bread in the house, stop eating it. If it hasn’t gone stale after the 7 days, then you can eat it.
    3) There is no 3. End of list.

    Now, be gentle please, but “have at it”. I want to know if anyone else sees it this same way, and I want to know what people see as holes in my logic or errors in my facts.

    • Rachel says:

      I appreciate your concise analysis of the commandment.

      Thinking about leaven in biblical days, wasn’t it in the air? One would leave the flour and water mixture sitting out for a time, and leaven in the air would land on it and cause the mixture to bubble, or ferment. Add more flour, knead, and you get leavened bread.


    • daniel says:

      I concur. I used to fret over the definitions of others, but I finally realized the wine at a Seder (which isn’t described in the Torah) is fermented! And the unleavened bread’s main ingredient can be made to leaven, ergo, leaven must be yeast – so, as long as I stick to my soft corn taco shells, my chicken tamales, my salmon salad on soda crackers …. etc., I should remain Torah compliant. I don’t drink wine and stay off my weekly pint (or 2) of ale. Any remaining cheese or bread I pop into the freezer for the week. Keep It Simple, Students.

  • Shalom says:

    Ever heard of something called a tortilla? Lamb tacos!

    • Neville says:

      Check your store-bought tortillas. I just did. “Contains: …yeast”

      • MonR says:

        We’ve bought tostada shells the past 2 years and they didn’t have yeast-and the lamb tostadas were fantastic, especially with some cilantro! 🙂

  • Joy says:

    I am trying to understand. Quoting Nehemia from above, “If the dough rises, that grain is subject to becoming Hametz (leaven). On the other hand, if the dough spoils, then that grain or plant is not leaven-able and it can be freely used and cooked on Passover.” So the Hametz grains (wheat, spelt, barley, oats, rye, and maybe millet) should NOT be used during Unleavened Bread, correct? But wait, quoting the sages above, “whatever experimentation shows to leaven can be used for Matzah”, and “Therefore, in truth, there are six types of grain that can leaven and from which Matzah can be made: the aforementioned five as well as millet. And if Hametz is made from any of these it must be destroyed.” Is this not contradictory? Use the Hametz grains to make Matzah? But if you do, destroy it? Can someone please explain what I am missing? Also, doesn’t this indicate that the grain used is what matters, not whether yeast or baking powder is added to the dough? I have been thinking all along that I had to toss the yeast out of the house, and check all food labels for yeast as an ingredient. I don’t want to be caught up in legalism, I just want to follow YHVH’s commands. However, I have to understand them in order to follow them.

  • Ann Correa says:

    I thought leven was caused by wild yeasts that can sour, or leven bread dough, juice to wine, wine to vinegar,milk to yogurts or cheese, etc.
    I would think anything that is not allowed to let these spores grow would be considered unleavened, because it has not been allowed to become contaminated with the yeast spores.
    Just a thought. ..

    • Ann Correa says:

      I’m not Jewish, so maybe my understanding is different.

    • daniel says:

      As I understand it, wild yeast has to be present in large enough quantities under specific conditions of time, temperature, etc. to make bread. Usually it had to be collected and added. That white, powdery coating seen on dark grapes is wild yeast. That’s why it’s not necessary to add cultured yeast to the grape harvest to make wine, because it’s built-in to the main ingredient.

  • Tim Beeker says:

    Doesn’t the word “pesach” have a primary and secondary connotation to it? In the verb form, it means to “skip” or “passover”, but in the noun, it means “victim”? One is the observance, while the other is the item of focus in the observance?

  • David says:

    Hi everyone,

    I like to make fresh bread, its one of the few times Im allowed in the kitchen and not get chastised for making a mess (lol). I love the smell of leavened bread when it bakes, the dough too is oh so yummy and fresh baked leavened bread hot out of the oven with melted butter is even better. Its worth the wait!

    But when the feast nears I dont really fret over what the scientific definition of leaven is or what it could or might be. What I throw out is the actual leavening agents I use to make my bread and sahti with. My understanding of that act is that it was a way to reduce the temptation of using it in bread, because there was no time to wait for it to rise and savor it. No time to dress the animal, just throw it over the fire cook it whole and have at it. Bitter herbs? Looking at how many of us prepare greens today I will surmise they did the same in Egypt and say they had no time to sweeten them with dressings and spices they were eaten as is, bitter. It seems to me everything about the meal indicates that not only was it eaten in haste but prepared in haste as well. To get ones nourishment just before for that long journey ahead.

    Anyway, thats my opinion, 🙂

  • Dave Christensen says:



    The Hebrews left Egypt early in the morning. They did not have time to put leaven in the bread and wait the precise amount of time for the dough to rise. Neither did they have the time to bake loaves in an oven. It is time consuming to bake loaves of bread. And it would be more cumbersome to carry loaves of bread with you on the road, along with your kids and everything else you own.

    So in the morning they took their flour, added water and kneaded it into dough. They did not add leaven. Then they kept the dough in their kneading bowels, covered with their cloaks, and carried it with them on their shoulders as they traveled across the hot desert. When they camped that evening they built campfires and made the dough into flatbread, the way primitive people all over the world do it.

    The flatbread was compact and could dry quickly so that it could be carried with them on their journey as a survival food that would last for days.

    THINK ABOUT THIS! They carried wet dough with them. Why? There are nutritional reasons.

    All seeds and the flour made from seeds have lectins and other chemicals in them that protect the growing seeds. But these chemicals are irritants to people’s digestion.

    The process of leavening the bread breaks down these chemicals and starts digesting the gluten. Baking the bread half an hour in an oven also aids digestion. Baking loaves of baked bread is the best way for people to eat wheat. Anything you can do to make the process last longer helps the people eating the bread.

    But they did not have time to leaven their bread. And they would not be able to cook it much. Making flat bread only takes about 3 minutes over the fire.

    The least they could do was to let the dough sit while they traveled. Letting it set would do something to start digesting the components of the bread and would contribute something towards better for digestion and nutrition.


    There is naturally occurring yeast in the air. The dough is going to get a tiny bit of leavening just from the air. The naturally occurring yeast would not be enough to raise the bread.


    There is a tradition of making the unleavened bread in under 18 minutes, to avoid naturally occurring yeast from having time to leaven the dough even the slightest bit. I find this obsessive paranoia against naturally occurring yeast to be a contradiction to the Torah and to nutritional wisdom.

    If we want to be accurate to the Torah, we should make the dough in the morning, let it set all day, and make flatbread out of it before sundown, and then eat it. This will be true to the original story and will benefit the nutrition. Yehovah cared about His children’s health.

    It seems to me that the message of the unleavened bread is not a purist paranoia against naturally occurring yeast. Yeast is not a poison, spiritually nor physically. It’s a luxury. And it’s part of nature. They couldn’t leaven their dough only because they had to leave Egypt in a dramatic hurry and didn’t have time to prepare food for the trail.

    The unleavened bread represents an traveling food, made in haste, made from pure basics, that could be stored a long time for their journey. The bread tells the story of the journey. We want to remember the journey. The road to freedom that our forefathers took for us required some sacrifice and hardships including eating unleavened bread.

    So why have a fetish against small amounts of natural yeast? That is just looking for one more thing to make obsessive rules about, while contradicting the actual event and the wisdom.

    They yeast is not the problem, the Pharaoh is.

    The story is not about our own acts of perfection and purity. It is about Yehovah caring for us and guiding us to freedom with His outstretched arm.


    They would have used whole wheat flour. The white flour that people use today has had the nutritious bran and germ removed. White flour is nutritionally useless.

    There is no recipe for the bread in the Torah. It was just made quickly with basic ingredients. I imagine if they liked a pinch of salt in it, or a little oil, if they had it on hand, some might have added salt or oil. We will never know. They did what they could under the circumstances to keep their families strong and healthy.

    • UKJ says:

      Very interesting Dave,

      If I may add just a few more points..

      To the Christians leaven represents sin, coming out of Egypt represents coming out of sin and good points are being raised as the Israelites have learned many idol worship practices, the golden calf is a reminder of such!

      In my understanding leaven is produced by creating a sourdough which is left to ferment and then part is used to create the bread, this means it is a continued process. One bit of the old carries forward to the new, so to speak.

      Yehovah wanted to create something new with the people, hence the old leaven represents the “cut off”

      The new bread “of a different kind” came from heaven in the form of the manna. Just my view..

    • j says:

      Ezekiel 4:9-17New International Version (NIV)

      9 “Take wheat and barley, beans and lentils, millet and spelt; put them in a storage jar and use them to make bread for yourself.

    • YIshis Lassie says:

      THANK U SO MUCH FOR TAKING THE TIME. I FIND THAT HIS COMMANDS ARE very practical and for our highest good. This makes total sense!

  • Daniel says:

    I wonder if calling some one a fool is a form of leaven? Didn’t know being pious is not foolishness.

  • mark says:

    shalom nehemiah, here is my question, from your article the karaite sages point out five grain that will become hamets: if a leavening agent is added to any grain not listed in five does that product then becomes hamets and thus unsuitable for consumtion during chag hamastot.

  • James Riley says:

    Thank you for the insight as to the physical application of this. What is the traditional spiritual interpretation of this? We have always seen the spiritual side of this to be that we need to examine the practices of our house for teachings and practices that have soured or bloated beyond their initial intent. (ie. Maybe a tradition that has evolved into something that is outside of Biblical.) Would this also seem relevant?

  • Nicholas Mansfield says:

    I was faced with an awkward situation. How to express accurately the Passover rituals. Is the Torah using slang here too? If we use the word slay, being some derivative of the word slaughter, as in ritual slaughter, to express the Hebrew for shachat, for Ex.12:21, then what of zebach in Ex.12:27? Passover was a completely unique event, being originally performed before the Tabernacle, or the Ark. Then things changed at some point, probably twice. Is Ex.12:27 looking forward in time? Zebach is the same term used again in Lev.17 for the right manner of taking an animal’s life with the altar (Ark in this instance) having been established, shachat for inappropriate, well illegal, actions. In the first instance there was no threat of a future judgment, it was immediate. Do this, or game over for your firstborn men, and beasts. So at the point of Leviticus being established as a section of Law, has Passover become an atoning sacrifice? Then is zebach always pointing to an atoning sacrifice? Is it simply a picture of the past? Later on there is a national lamb selection and offering, yet by whom, and where, was this prescribed?
    Thanks Nehemia for helping me and many others to see how certain things were to be performed. Yet how are we to interpret the instructions for what can no longer be performed? Surely these are the questions we are to ask as we attempt to recreate a shadow of former days, and honour the Word of YHWH.

  • wordslea says:

    What did they coming out of Egypt consider leaven? How did they make their bread rise? I use yeast or baking powder, so isn’t it enough to rid my cupboard of yeast and baking powder?

    • They had two ways of making it rise: 1) Let it sit for 2-3 days, 2) Mix it with “leaven”, what we call “starter dough” today. Modern yeast is actually “brewers’ yeast”, a by product of beer production.

      • sandra coats says:

        I have a flat bread recipe I was given while visiting the middle east, that I’d wondered how far back it went. It’s made from wholemeal flour, salt and water sitting 2-3 days to ferment, then cooked on a hot oily surface. If I cook it immediately after mixing, it reminds me of homemade matza. It didn’t make sense to me to assume all flat breads were baked, because while wandering the desert did they really lug around or keep building ovens? It makes more sense if they cooked it on a hot surface because a pan can be easily transported. This bread would fit right in with that environment.

      • Darlene DeSilva says:

        I make a flat bread without yeast, baking powder, or baking soda. I use Einkorn…,the original wheat, oil, butter and a sweetener of sugar or honey. I only let it rest on the counter for 10-15 minutes, not for fermentation purpose but to let the gluten relax. I have been using this flat bread for “Unleavened bread”. My family loves it and I do not believe I am violating the unleavened bread restriction during the week of “Unleavened Bread”. Please let me know if I am. I think everyone would have been in my camp wrapping their food in my flat bread… 🙂

  • Mimi says:

    Applause thank you

  • Yehuda Ben-Yosef says:

    Good food for thought here Nehemia. Have a blessed holydays (holidays)… We had a great meal and awesome lamb and enlightening fellowship last evening here in Oregon….with fellow Jews and Israelites in the diaspora (a.k.a. Joseph’s kin) sharing a Pesach meal together and praising YHWH. Can these dry bones come to life? Ezk 37….. They already have! Shalom. Yehuda Ben-Yosef

  • Jenina Conradie says:

    We ate of the tree of Life and I am so encouraged as I participate in being added to the people of יהוה. Thank you for this recipe. I used wheat free flour, macadamia nut oil and luke warm water. It was a superior unleavened bread. We loved it!

  • I am not sure if this post is monitored, but if it is, I have a question. I have read and reread the hebrew on Debarim 16:4. It seems to me it could be stating and even more than likely is stating that “And no leaven should be seen with you in all your border for seven days, neither should any of the meat {remain} which you slaughter in the evening {on} [toward] (before) the first day until morning {dawn} [break of day].”
    If this is not a viable and possibly accurate understanding of this verse, will someone please explain to me ( grammer wise) why?

  • When I say dinner, is called afternoon tea here in Australia and starts around 4 and goes till sunset.

  • Thank you for this WONDERFUL recipe! The first time we got it right! Had dinner at the neighbours and rushed over to home to do the proper Passover with the proper bread, Thrown out our vegemite and our dog biscuits and dog roll of wurst and well you know half the contents of our cupboard near enough the week prior., WIshing everyone a safe and blessed Passover and Holy Feast.
    LOVE the Passover.

  • Devora Forsman says:

    I have believed for years that it was bread starter that they were to get rid of. You can’t get all the yeast out your home because it is everywhere. I also learned about this when I started making bread for my family. Be blessed and bless Yehovah!

  • Vicki says:

    I am not doing Passover or the Feast of Unleavened Bread this year because I just started studying with you and Keith Johnson and I haven’t made this teaching “my own” yet.Coming from outside the Jewish tradition and just now learning this with you and Keith I got to thinking about leaven. I don’t exactly know what leaven is other than something used to make bread rise.Doing a little cursory research on ancient breadmaking the Egyptians mostly had a diet of bread and beer.There are old hard bread fossils placed for the afterlife in Egyptian tombs. Beer can be used as a leavening agent. Yeast found on grape peel can be used as a leavening agent. I was big into breadmaking years ago and I was given an Amish bread starter and I remember keeping it in the fridge and having to feed it daily with sugar. Sourdough bread is also made with a starter that has to be fed daily to keep the starter, or the bread “riser” alive. Grain mixed with water and left on a kitchen counter will ferment over 2-3 days and can be used as a starter.I really am wondering if the commandment to remove leaven and eat unleavened bread is not just the letter of the law but the spirit of the law. Women made the bread for the family, it took time and also the starter had to be cared for and babied. If I were part of the mixed multitude and a woman leaving Egypt and “running for my life” bread starter would be the last thing on my mind. Have a wonderful passover and Feast to all commemerating and remembering the scripture. For me, maybe next year.

    • Gavri'el says:

      Leavening from a Scriptural perspective is the mixing of Truth with lies, which is what we see in western churches. You could say that Satan is good at this, he adds some traditions of men to Yehovah’s word and makes it seem as if they are the commandments of Elohim. Leavening or the puffing up can also be seen as the arrogance of a person whom assumes they know more about His word than they acutally do, so again adding too and I guess diminishing from.
      I look at it from this perspective, if its not in His Word, then do not add it, and if it is in His word, do not detract from it.

  • jess says:

    Well I do passover abouf 20 to 15 min before sunset and eat it in haste.