4. Transformation (Istihala)
197. If a Najis thing undergoes such a change that it assumes the category of a Pak thing, it becomes Pak; for example, if a Najis burns and is reduced to ashes, or a dog falls in a salt marsh and transforms into salt, it becomes Pak. But a thing does not become Pak, if its essence or category does not change; like, if wheat is ground into flour, or is used for baking bread, it does not become Pak.
198. An earthenware or the like, which are made of Najis clay, is considered as Najis. Also, the charcoal, which is made of Najis wood, should be avoided.
199. A Najis thing about which it is not known whether it has undergone any transformation (Istihala) or not, remains Najis.
200. Any liquor, which becomes vinegar by itself, or by mixing it with vinegar or salt becomes Pak.
201. A wine, which is made from Najis grapes, will not become Pak by turning into vinegar. Also, if any external Nejasat reaches it, as an obligatory precaution it should be avoided.
202. Vinegar which is prepared from Najis grapes, raisins, and dates is Najis.
203. If stalks from grapes or dates are added, and then vinegar is poured over it, or, if cucumber and brinjal is added before dates, raisins, and grapes turns into vinegar, there will be no harm. Grape Juice Turning into Vinegar.
204. The grape juice which ferments, before two thirds of it evaporates; in other words, before two-third of it is reduced and one-third remains, is not Najis but it is Haraam to drink. If it is proved to be intoxicating, it is both Najis and Haraam, and it will only become Pak and Halal by turning into vinegar.
205. If in one bunch of sour grapes, there is one or two grapes, so that the juice prepared from it is called vinegar and it is not sweet and it ferments, then it is Pak and Halal.
206. A thing about which one does not know whether it is unripe grapes or ripe grapes will be Halal, if it ferments.