TABDEEL-E-MAHIYAT, [CHANGE IN THE ORIGINAL PROPERTIES OF A SUBSTANCE]
Tabdeel-e-Mahiyat is the total transformation of something whereby the original substance retains NO properties of its former state and differ completely from it in application. One must understand that to include everything and anything under this analogy or cite modern food production techniques does not necessarily satisfy the condition of Tabdeel-e-Mahiyat. A classic example is Gelatine, a thickener used in food derived from skins, tendons, ligaments, bones, to produce a gelling agent. However some remnant of the original product still remains in the final packaged product making it impure and improper for use despite the great chemical changes it underwent. Hence this will not be considered Tabdeel-e-Mahiyat or Halaal. The example given by ‘Allamah Ibn Aabideen in his Fatawa Radd-ul-Muhtaar on Nutfah [a drop of sperm] which is impure and changes after conception into ‘Alaqah [germ cell or clot] also impure but fertilizing into a Muzqah [embryonic lump] which is pure.
The second example quoted by him is of ‘Aseer [grape juice] which is pure but ferments and changes into Ghamr [wine] becoming impure and thereafter can further change into Khal [vinegar] which is pure again. Vinegar is prepared by two successive microbial process. The first being an alcoholic fermentation [which is Haraam] and the second an oxidation of alcohol by aceto bacter, when its molecular structure is changed and it ceases to be an intoxicant. Other varieties of vinegar are produced from beetroot, tarragon and alcoholic spirits. In vinegar the intoxicating factor is destroyed by the microbial process of oxidation hence it becomes permissible. Islam permits any variety of vinegar to be used as a condiment or preservative. In both cases the original state undergoes tremendous changes making the final product something altogether different. Soap also undergoes tremendous changes from its original substance, hence all soap will be permissible to use for Muslims.
‘Allamah Ibn Aabedeen says: We recognise that the changing of the original state of a substance is necessarily followed by the change in the qualities of the substance. We now come to the point whether the cause for the changes in the substance is purity or public predicament. Allamah Ibn Aabedeen rules that the actual case is public predicament and cites the example of soap made from impure oil which is pure because of public predicament. Fatawa
Mazahir ul Uloom vol.1 page 84-85 Fatawa Ibn Aabideen [Shaami] vol.1 page 217-218