The Jerusalem Council

A Global Association of Orthodox Jewish Disciples of Messiah Yeshua

What is Chametz? (It’s not Yeast)

Chametz is any food that contains wheat, barley, oats, spelt, or rye that has fermented. These particular grains will ferment by themselves in the presence of water. This process can begin in as little as 18 minutes.

Obvious foods such as breads, cakes, pastries, pasta, cookies, crackers, pretzels, breaded foods, etc. must be consumed or disposed of before Pesach. However, as we are not permitted to consume, derive a benefit from or possess any chametz we need to look a bit further. As such, to make sure that we have no chametz in our possession it is important to review all packaged products or processed foods. If they are not certified kosher for Passover, assume they are not. All raw fruits, vegetables, nuts, and kosher meats are kosher for Pesach. Sephardic Jews and now more and more Ashkenazi Jews do not remove or limit the use of legumes (kitniyot) for Pesach.

But what about Yeast?

Ex 12:33-34, 39 (NASB 1995 update) 33 The Egyptians urged the people, to send them out of the land in haste, for they said, “We will all be dead.” 34 So the people took their dough before it was leavened, with their kneading bowls bound up in the clothes on their shoulders. … 39 They baked the dough which they had brought out of Egypt into cakes of unleavened bread. For it had not become leavened, since they were driven out of Egypt and could not delay, nor had they prepared any provisions for themselves.

Dt 16:3-4 (NASB 1995 update) 3 “You shall not eat leavened bread [Chametz] with it; seven days you shall eat with it unleavened bread, [matzah] the bread of affliction (for you came out of the land of Egypt in haste), so that you may remember all the days of your life the day when you came out of the land of Egypt. 4 “For seven days no leaven [Se’or] shall be seen with you in all your territory, and none of the flesh which you sacrifice on the evening of the first day shall remain overnight until morning.

Se’or is what is prohibited in our homes. Yeast is natural occurring, living, microorganism which is everywhere. It is what ferments wines, beers, grains, etc. As we know we can have wine (as Yeshua and His disciples did at Pesach) we know that we can have some forms of yeast. What we learn is that all se’or is yeast, but not all yeast is se’or. (Just like all Levites are Hebrews but not all Hebrews are Levites. They may be Gadites, Ephramites, Jews, etc..)

The passages in Ex and Dt show us that the only ingredients for the bread were a fermentable grain, water, heat, and a short period of time. The opportunity for the grain to ferment after water was added over time is the key formulation. We know that if we add yeast or a lump of fermented sour dough to fermentable dough it is immediately considered fermented and is by definition se’or. Therefore, we know that yeast was not added. We also know that grains such as corn, rice, etc. rot if water is added to them and they are allowed to sit for a long period of time. They do not ferment on their own over time. As such, it was not corn meal or rice cakes that they were taking out of Egypt that did not have “time to leaven.” From this we learn that those grains are not required to be removed from our homes, even if they have been fermented with yeast. Conversely, we learn that the five grains that ferment in the presence of water, if there is any chance that they have been permitted to ferment since harvesting, must be removed from our homes.

Brewers yeast is one exception. As it is a fermented barley it is by definition chametz and all products that contain it must be removed for Pesach.

Baking soda, leavening agents, etc are irrelevant at Pesach and do not have to be removed from ones home, unless they are made from a fermented grain.

Other areas of consideration:

  • Pre-ground “raw” wheat flours are often presoaked in water before grinding and may or may not be kosher for Pesach and do require certification.
  • Oats are can also be “heat-treated” to keep them from rotting. If the “heat treatment” is done dry they are kosher for Pesach, however if it is done with “wet steam” they may be chametz and do require certification.
  • Barley and “pearled barley” are kosher for Pesach and do not require certification.
  • Sprouted Barley, barley malt, malt, malted barley, etc are by definition chametz.
  • Unfortunately, grains are sometimes used in products such as soda-pop and decaf coffee and are not listed in the ingredient list. Not all soda-pop and decaf coffee are forbidden at Pesach but they do require certification. However, because of the Ashkenazi limitation on kitniyot which includes corn syrup, no soda-pops are currently certified kosher for Pesach and therefore they should be removed and avoided during Pesach.
  • Beer, Whisky, grain alcohols, etc are by definition chametz and must be consumed or removed before Pesach.
  • All alcohols and wines should be checked to make sure they are in fact kosher for Pesach or they should be consumed or removed before Pesach.
  • Vinegar is a re-fermented alcohol. Malt vinegars are by definition chametz as is any product containing malt as it is made from a fermented barley. Wine, apple, and white distilled vinegars are usually fine for Pesach. However, white distilled vinegars can be made from wheat which would make it chametz and wine, apple and white distilled vinegars may contain additives that are chametz or be made on equipment that also processed chametz products such as malt vinegars. Care should be taken to review all products that contain vinegar. Some authorities in the US however do not have a problem with distilled vinegars as the majority of them used in processing foods (such as pickles, ketchup, mustard, olives, etc) or sold are made from corn and are therefore not chametz. They may not contain a hechsher saying it is kosher for Pesach however, because it does contain kitniyot which the Ashkenazi Jews avoid during Pesach. Many people do not remove it from their homes, but avoid consumption because of the vagaries surrounding products containing vinegar. As such consult your local Orthodox Rabbi for a ruling.
  • Girl Scout cookies are kosher, but they are not kosher for Pesach. Be sure to check when they will be delivered so that you do not have them delivered just before or during the week of Pesach before you order them.
  • For all corporate meals, congregational meals, or meals with guests, it is best to adhere to the strictest standard which is to not use any processed or packaged products unless they are marked kosher for Pesach. As stated before raw fruits, vegetables, meats, nuts and certain grains as noted are fine without a hechsher stating kosher for Pesach.


Cooking is permitted on festival Shabbats as long as the preparation has begun before the festival Shabbat began, the “eruv tavshilin” including the blessing, has been prepared before the festival. This permits cooking on festival Shabbats for meals to be consumed on weekly Shabbats that follow immediately after a festival Shabbat. Note that if a day is available between the festival Shabbat and the weekly Shabbat, cooking for the weekly Shabbat or the regular week day is prohibited on the festival Shabbat.

Cooking is always prohibited on the weekly Shabbat. This is the case even when a festival Shabbat follows immediately after the weekly Shabbat. In that case the “eruv tavshilin” including the blessing, must be prepared before the weekly Shabbat. Then after sunset on the weekly Shabbat, the cooking of the meals for the festival Sabbath may resume. Again, cooking on the festival Shabbat is limited to what will be consumed on the festival Shabbat. Cooking for a meal on a regular week day that follows the festival Shabbat is strictly prohibited.

Ex 12:14-16 14 ‘Now this day will be a memorial to you, and you shall celebrate it as a feast to the Lord; throughout your generations you are to celebrate it as a permanent ordinance. 15 ‘Seven days you shall eat unleavened bread, but on the first day you shall remove leaven from your houses; for whoever eats anything leavened from the first day until the seventh day, that person shall be cut off from Israel. 16 ‘On the first day you shall have a holy assembly, and another holy assembly on the seventh day; no work at all shall be done on them, except what must be eaten by every person, that alone may be prepared by you.

By reason of specific to general we see that because cooking is permitted specifically on the festival Sabbaths of Pesach, cooking is permitted on all festival Sabbaths (except Yom Kippur which is a fast day.) By applying the 9th rule of Yishmael we see that the permission to cook on a festival shabbat is a specification that is to provide a leniency to a general prohibition.

Ex 16:4-5, 15-29 4 Then the Lord said to Moses, “Behold, I will rain bread from heaven for you; and the people shall go out and gather a day’s portion every day, that I may test them, whether or not they will walk in My instruction. 5 “On the sixth day, when they prepare what they bring in, it will be twice as much as they gather daily.” (here we see that the preparation is to take place on the sixth day. They are not permitted to gather it or cook it on the seventh day, the weekly Shabbat.) … 15 When the sons of Israel saw it, they said to one another, “What is it?” For they did not know what it was. And Moses said to them, “It is the bread which the Lord has given you to eat. 16 “This is what the Lord has commanded, ‘Gather of it every man as much as he should eat; you shall take an omer apiece according to the number of persons each of you has in his tent.’ ” 17 The sons of Israel did so, and some gathered much and some little. 18 When they measured it with an omer, he who had gathered much had no excess, and he who had gathered little had no lack; every man gathered as much as he should eat. 19 Moses said to them, “Let no man leave any of it until morning.” 20 But they did not listen to Moses, and some left part of it until morning, and it bred worms and became foul; and Moses was angry with them. (cooked or raw it went bad by the following morning.) 21 They gathered it morning by morning, every man as much as he should eat; but when the sun grew hot, it would melt. 22 Now on the sixth day they gathered twice as much bread, two omers for each one. (First we note they gathered twice as much on preparation day, but we see that was not enough and Moses corrects them.) When all the leaders of the congregation came and told Moses, 23 then he said to them, “This is what the Lord meant: Tomorrow is a sabbath observance, a holy sabbath to the Lord. Bake what you will bake and boil what you will boil, (all of it on preparation day) and all that is left over put aside to be kept until morning.” (what was not consumed is to be set aside. They are not to set it aside raw as tomorrow is a Shabbat observance, a holy Shabbat to HaShem.) 24 So they put it aside until morning, as Moses had ordered, and it did not become foul nor was there any worm in it. 25 Moses said, “Eat it today, (There is no permission to cook it. Cooking on a weekly Shabbat is strictly prohibited. That is why there is a leniency provided for festival Shabbats.) for today is a sabbath to the Lord; today you will not find it in the field. 26 “Six days you shall gather it, but on the seventh day, the sabbath, there will be none.” 27 It came about on the seventh day that some of the people went out to gather, but they found none. 28 Then the Lord said to Moses, “How long do you refuse to keep My commandments and My instructions? 29 “See, the Lord has given you the sabbath; therefore He gives you bread (the word here is lechem, inferring cooked manna as it is in the form of a food stuff, not raw.) for two days on the sixth day. Remain every man in his place; let no man go out of his place on the seventh day.”

On the Pashat (plain meaning) of the text we see that cooking is strictly prohibited on all weekly Shabbats.

As cooking is permitted on festival Shabbats for food to be consumed on the festival Shabbat, it is customary to bless HaShem for such a privilege and to show recognition of the keeping of the commandment not to cook on the weekly Shabbat. In blessing HaShem before the festival Shabbat, with the comingling of foods, we are setting apart the festival Shabbat and showing that we are keeping it holy by not doing general cooking for regular week days.

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