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This Halacha will discuss the general laws involved in making a Kosher for Pesach dish. A Kosher for Pesach product refers to a food that does not contain any ingredients of Chametz [Halacha 2] or Kitniyos [Halacha 6], and has been supervised accordingly to attest to this. There are also various products that are not eaten due to worry of Chametz infiltration. [Halacha 7] In addition, there are foods that are avoided due to custom, each in accordance to his community and family, even though they contain no worry of Chametz or Kitniyos. [Chapter 7] In addition, even when no problematic ingredients are added to the food, in order for it to be Kosher for Pesach, certain guidelines must be followed, as explained in this Halacha.
Made with intent to eat on Pesach: If a dish was made without intention to eat on Pesach then is forbidden to be eaten on Pesach. This applies even if the person says that he is positive that no Chametz fell into the food [and that a Non-Ben Yomo Chametz pot was used]. Accordingly, only foods that were supervised for the sake of eating on Pesach, may be eaten.
Not to use Kosher for Pesach foods which one used for Chametz foods: Some are stringent not to eat foods which have been opened and used for Chametz meals, even if the foods are Kosher for Pesach. [Thus, for example, if one opened a Kosher for Pesach bag of potato chips when still eating Chametz, it is no longer to be eaten during Pesach, unless one was careful upon eating it.] However, in places that it is difficult to easily get a replacement of that food, then people are not accustomed to be stringent.
A food is only considered Kosher for Pesach if all the following conditions are fulfilled:
1. No Chametz ingredients or infiltration, as explained in Halacha 3.
2. No Kitniyos ingredients, as explained in Halacha 7.
3. No foods that are customarily avoided due to suspicion of Chametz infiltration, or due to custom.
4. The food was prepared/cooked under supervision for the sake of eating on Pesach.
5. The food was not eaten by a Chametz meal prior to Pesach.
Must all food products eaten on Pesach have a Hashgacha for Pesach? May one eat/purchase a food that does not contain a Kosher for Pesach label if it does not appear to contain Chametz?
In today’s modern food production industry, there are thousands of ingredients and trace ingredients added to the most basic and simple food products, and many of these ingredients derive from Chametz or Kitniyos. Their names, even when listed, are misleading and the Chametz or Kitniyos may be an inconspicuously hiding in the seemingly innocent food ingredients. Now, as explained in Chapter 2 Halacha 1H, an intentional Chametz ingredient is not nullified even in 1000x. Hence, in order for a processed food to be Kosher for Pesach, it does not suffice to simply read the ingredients, and asses that it does not contain Chametz and rather it must have a Kosher for Pesach label. The Hashgacha organization is charged with the task of performing a wide investigation into all the ingredients used by the company to make the food, and see which derive from Chametz or Kitniyos.
Raw non-processed ingredients: All raw unprocessed ingredients [i.e. fruits, vegetables, nuts] may be purchased without a Hashgacha for Pesach.
2. From what time on Erev Pesach must one be careful to only eat Kosher for Pesach products?
Beginning from the start of the 5th hour of the day on the 14th of Nissan, it is forbidden to eat Chametz. Accordingly, beginning from this time, one must to be careful to only eat Kosher for Pesach products.
At what time must Ashkenazim stop eating Matzah Ashira [egg Matzah]?
It is forbidden to eat Matzah Ashira starting from the time that it is forbidden to eat Chametz, which is from the 5th hour of the day on Erev Pesach.
From what time are those who are accustomed to not eating processed foods to begin their stringency? From the night of Pesach or from 5th hour of Erev Pesach?
One is to avoid eating these foods starting from the 5th hour of the day. However, many are lenient to eat processed foods up until the night of Pesach. See Chapter 7 Halacha 5A for further details on this matter.
From what time are those who are accustomed to not eating spices or unpeeled foods to begin their stringency? From the night of Pesach or from 5th hour of Erev Pesach?
One is to avoid eating these foods starting from the 5th hour of the day. However, many are lenient to eat these foods up until the night of Pesach. See Chapter 7 Halacha 7 for further details on this matter.
 Admur 447:43 regarding fat and 47 regarding Ben Yomo pot
 The reason: Being one did not supervise the food, perhaps Chametz fell into it, and if the food is a type of food which will not dissolve the Chametz crumb, as is the case with fat, then the crumb would remain Being in the food on Pesach. [Admur 447:43] Furthermore, even if the crumb were to dissolve in the food, it is still forbidden to be eaten on Pesach, as perhaps the person was not careful to avoid using a non-Ben Yomo Chametz pot, just as he was not careful to avoid Chametz from falling into it. [Admur 447:47]
 Admur 447:47
 The reason: As a person can only remember something if he was intentionally looking out to avoid it. Thus, since here he did not have intention to avoid Chametz, therefore, he would not pay attention if a crumb were to fall inside, and now he no longer remembers this. [Admur 447:44]
 Admur 447:49
 The reason: As perhaps one returned leftovers from a meal back into the original container, and at times this food may have in it crumbs of Chametz. [Admur ibid]
 See Chapter 2 Halacha 3B!
 Admur 444:3; 471:6
Other opinions: Some Poskim rule that even according to Ashkenazim one may eat Matzah Ashira [egg Matzah] until midday. [Noda Beyehuda 21 brought in Kaf Hachaim 443:7] However, practically, the custom is to avoid eating Matzah Ashira beginning from the time that one must stop eating Chametz, which is the beginning of the 5th hour. [Piskeiy Teshuvos 444:3]