The K’zaisim (minimum required amount) for Matzah:
Introduction: We have spent many long days on researching the correct shiur of a k’zayis. The work was particularly difficult because all the Shiurim are originally given in volume and we had to convert the amounts to weight, so that they could be used practically. (The only way the original measurements could be used is by crushing the Matzah and measuring its volume.) The weight measurements are especially useful, as we will need to know the matzah’s weight anyways in order to calculate the amount of carbs it has (more on that later). This explains why we state the weight amounts in grams, and not in ounces; we count carbs in terms of grams. Acquiring the shiur in measurements of weight wasn’t an easy job, as we found different opinions regarding the formula for converting cc (a measure of volume) to grams (the measure by weight). We therefore used the most stringent shiur, taken from the sefer “Middos Vshiuri Torah”, which the author figured himself using special tools. Although certain factors, such as the wetness of the matzah, might influence its weight (If a matzah is baked for a few seconds more, it will weigh less.) the formula we used covers that margin too. When you follow our shiurim, you might eat more than needed, rather than less. [Other sources that were used for the Shiurim are “Piskei Tshuvos” from Rabbi Simchah Benzion Rabinovitz shlit”a, “The laws of Pesach” from Rabbi Blumenkrantz shlit”a, “Seder H’oroch”, and “Halachas of K’Zayis” from Rabbi Yisroel Pinchos Bodner shlit”a. Rabbi Bodner also shared his vast knowledge with us over the phone.] In addition to the precise shiur by weight, we have included each shiur in comparison to a whole matzah (i.e. third matzah, quarter matzah, etc.). You may notice that it is almost impossible to be exact using this method of measurement, but we’ve included it to give you an approximate idea of the size and shape of the portion under discussion. Machine matzahs are generally uniform in size and thickness. Therefore, one shiur can be given which will be good for all machine matzahs. However, handmade matzahs, commonly referred to as shmurah matzahs, can vary significantly in weight, size and thickness. For this reason, it is impossible to assign a precise shiur as a standard k’zayis for all hand-made matzahs. One can, however, get a close approximation of the shiur needed, by weighing the matzahs. Typically, thin matzahs weigh 51 grams; medium-sized matzahs weigh 58 grams; and thick matzahs weigh 72 grams. [Usually, one would get nine thin matzahs to a pound, 7 ½ medium matzahs to a pound, and 6 thick matzahs to a pound.] The carb amounts we’ve used were supplied by the Manischewitz matzah manufacturing company.
Serving size: 1 Matzah (32 grams)
Total carbohydrate: 27 grams
Dietary Fiber: 1 gram
Based on the above information, matzah has a carb factor of 81%, or 0.81. (For instructions on using carb factors, refer to our Tu B’shevat article.) According to the matzah bakeries, the nutrition facts would be the same for shmourah matzah and for machine matzah. Although the amount of wetness in hand-made matzahs can vary, there is no way to have a more exact figure. Some matzah bakeries claim that their matzahs have more bran than others, which increases fiber content and reduces the effective carb content. However, we have not been able to get any nutritional data on that. (If you do use these matzahs, you may be advised to underestimate their carb content slightly.)
[Note: In previous articles, we stated that matzah has a carb factor of 70%. This was based on the nutrition facts of chametz’dige matzah. The carb factor for pesach matzah is 81%.]
To Keep in Mind
In the Poskim, we find that people who are sick (cholah) can use the smaller shiurim. A diabetic is not a sick person, but if one controls his/her carbohydrate intake due to a health reason such as diabetes, especially if his/her preferred option of treatment is a reduced carbohydrate diet, he/she would be permitted to use the smaller shiurim. (Of course, discuss this with your Rav who understands diabetes.)
The Zohar Hakodosh states that matzah is “Meichlah D’asvasah” (a food that heals). People mistakenly assume that eating matzah can’t cause harm because it is a healing food. However, we know that an overdose of medication may be very harmful, and the same is true with matzah. It will heal when consumed according to the correct dosage, but not when overdosed. The Nodah B’Yehudah, who originated the most stringent shiurim, states that in the case where his new, larger shiur would result in a leniency, the smaller shiur should be used. It is also well known that although the Brisker Rav zt”l was very stringent in all halachic matters, he was unusually lenient about the halachos of fasting on Yom Kippur. He explained that by being lenient with a mitzvah due to health reasons, he was indeed being stringent with the mitzvah of “vchai bahem” (and you shall live in them). The same could be true here: if one would act stringent and use larger shiurim at the risk of neglecting his personal health, it would be considered a leniency in the all-important mitzvah of “v’chai bahem”. Even the Nodah B’Yehudah did not approve use of the bigger shiurim where it would result in a leniency, as would be the case here. It is also remarkable to note that the Chazan Ish, who is famous for advocating the largest shiurim, actually used the smaller shiur (17 grams of matzah) for himself.
The various shiurim: There are differing opinions about the correct measurement of a k’zayis. The Shulchan Oruch rules that a k’zayis is half of an egg, while the Rambam holds that the proper measurement is a third of an egg. There is further debate on exactly what amount constitutes the halachic measurement of an egg. The Chazon Ish held that an egg is 100 cc. Most follow this opinion once a year, for the first k’zayis of matzah on Pesach. The opinion of the Grach Naah is that an egg measures 57.6 cc, and the sefer “Halachos of K’zayis” uses the measurement of 55 cc for an egg.
We can sum up these opinions into three separate shiurim, all of which will be used in this article. They are:
1) A k’zayis is half of an egg, or 50 cc. [Chazon Ish zt”l] 2) A k’zayis is half of an egg, or 28.8 cc. [Grach Naah] 3) A k’zayis is a third of an egg (with the egg measuring 55 cc), or 18.3 cc. [Rambam]
[We have converted these shiurim to amounts in weight by using the formula of 100:55 meaning that 100 cc equals 55 weight grams.]
Please note that there are smaller shiurim that we have not included in this article. If one needs to restrict carbs even further, the issue should be discussed with a Rav (and you can also give us a call for some more ideas). Which one of the Shiurim should be used? Moitzi Matzah: The mitzvah to eat a k’zayis of matzah on the first night of Pesach is a d’oraysa (Torah commandment). Therefore, we are required to use a shiur that conforms to even the most stringent methods of calculating a k’zayis, so as to be sure of fulfilling the mitzvah. The first shiur mentioned above, that of the Chazon Ish, is the most stringent, and therefore the preferred measurement for motzi matzah on the first night of Pesach.
This shiur (27.5 grams) contains 22.3 grams of carbohydrate. (27.5 X 0.81 = 22.3)
Use the following guidelines: