Shulchan Aruch: Chapter 464 - [The Laws Pertaining to] Mustard Into Which Flour was Mixed

SECTION 464 [The Laws Pertaining to] Mustard Into Which Flour was Mixed (1-2)

1 [The following laws apply to] all types of dips that contain vinegar or other sharp substances into which meat is dipped and into which flour is commonly added:1 [Since] the flour will become chametz because of the sharp substances if [even] a small amount of water is added,2 it is forbidden to add flour [to these dips if they will be eaten on Pesach], because [they are like a mixture of] mei peiros and water, which cause [the flour] to become chametz rapidly.3

If [a person] violated [the above directives] and added flour [to such a dip] on Pesach, one cannot remedy the situation by eating the dip immediately.¹ [The situation does not parallel one in which a person] was given license to bake a dough that was kneaded with mei peiros immediately [after kneading it].4 In that instance, [leniency was granted because] the dough cannot possibly become chametz since it will be baked immediately. By contrast, [a person] will perforce delay slightly while partaking of [sharp] dips in which meat is dipped.5 Since [a mixture of] mei peiros and water causes [flour] to become chametz rapidly, there are grounds for concern that [the flour in the dip] already became chametz as soon as the person began eating. Therefore, there is no way to remedy the situation except to burn the dips immediately after the flour is [mixed] into them,6 since it is forbidden to maintain possession of them.

To which [types of dips] does the above apply? To all dips other than mustard. If, however, one violated [the above directives] and added flour to mustard, the situation can be rectified by eating the mixture immediately.7 There is no concern that the flour already became chametz immediately when [the person] began eating.

[The rationale is that] mustard is sharp (even [sharper] than peppers, [in which instance,] since [the peppers] are sharp, they will cause the dough to become chametz faster [than usual]. However, the mustard is) extremely sharp. As a consequence, it will not allow the flour [mixed] into it to become chametz rapidly.

2 As was already explained in sec. 453[:4], the custom in these regions is not to partake of mustard at all on Pesach, for the reason explained there.⁷ Even if [the mustard seeds] were crushed, ground, and mixed together with wine before Pesach, one should nevertheless refrain from partaking of [the mustard mixture] on Pesach. [The rationale is that] the mustard is of primary importance [in the mixture], and it is noticeable and apparent. Therefore, such a mixture is not one which may be permitted even on Pesach, as explained [in sec. 453:5].8

Moreover, [the Sages] ruled leniently only with regard to a mixture that came about as a matter of course. When, by contrast, one mixes [a forbidden substance with a permitted substance] actively and intentionally with the intent of partaking of [the mixture] on Pesach, he is not allowed to partake of it [on Pesach].9