Assalamualaikum ustaz. What is the ruling of boiling or blanching chicken before cleaning and removing its excrement? Hope for an explanation.
Waalaikumussalam wrt. wbt.,
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions, and all those who follow his footsteps until the Final day.
We begin with the statement of Allah SWT:
يَا أَيُّهَا النَّاسُ كُلُوا مِمَّا فِي الْأَرْضِ حَلَالًا طَيِّبًا
“O mankind, eat from whatever is on earth [that is] lawful and good,” 
The above verse shows food to be eaten should fulfil the two criteria, lawful and good.
Other than that, al-Tabari also stated the word ‘tayyib’ means (food) that is pure and clean from najis and is prohibited. 
Usually, chicken that is slaughtered will be blanched in boiling water first before it is cleaned and its excrements are removed to ease the process of removing its feathers. Thus, if the chicken is blanched in boiling water that is less than two qullah, then the boiling water will turn to najis because najis is put in it even if it is in a small amount and none of its original attributes in terms of its color, smell and taste changed.  However, if the chicken has been cleaned from all of its filth and excrements before being blanched in the boiling water, then the water doesn’t turn into najis.
Likewise, scholars have differing opinions regarding the urine and excrement of animals that are halal to be eaten – that is whether they are considered najis or not? Regarding this matter, scholars of madhhab Maliki and Hanbali as well as Muhammad bin al-Hasan and Zufar, scholars of madhhab Hanafi hold the opinion that filth – urine and excrements – of halal animals to be eaten are pure and aren’t considered najis regardless of whether the animal is still alive or after it is slaughtered. This follows a hadith of al-‘Uraniyyin, where Rasullullah PBUH commanded them to drink camel’s urine and milk. If it is najis, surely the Prophet PBUH wouldn’t command as such. The same is stated in a hadith which narrated Rasullullah PBUH once prayers in goat’s stables. Thus, if the urine and excrement of halal animals to be eaten are considered najis, certainly the stable area is considered najis for it wouldn’t be safe from the animal’s urine.
While Abu Hanifah and Abu Yusuf are of the opinion that the urine of halal animals to be eaten is light najis. Whereas its excrement is heavy najis according to Abu Hanifah while Abu Yusuf considered it light najis. The difference between light and heavy najis here according to the scholars of madhhab Hanafi in terms of the forgiveness given to the najis. In other words, najis that are considered light are given more forgiveness, while heavy najis are less forgiven and the difference isn’t in terms of the methodology to clean it, for they state that there isn’t any difference in how to clean both of the najis.
As for scholars of madhhab Syafi’i, their opinion states that the urine and excrement of halal animals to be eaten is najis.  This is based on the hadith narrated by Ibn Mas’ud RA, he said:
فأتيتُه بحجرَيْن وروْثةٍ فأخذ الحَجرَيْن وألقى الرَّوْثةَ وقال: إنَّها رِكسٌ
“So, I brought him two stones and a piece of dung. He took the two stones and threw the dung away, saying: ‘It is impure.'” 
Hence, they who hold onto the opinion of scholars that states the urine and excrement of halal animals to be eaten is pure and not najis, then it is fine to directly blanch the chicken before cleaning it from all of its filth and excrements, for it doesn’t turn the boiling water into najis. However, the remaining question is if the filth – urine and excrement – is considered najis, what is the ruling of blanching the chicken before cleaning it since it will turn the boiling water into najis and whether the chicken is permissible to be eaten?
Blanching chicken in najis water
Scholars discussed this matter and differed. Some of them stated that if the meat is cooked with najis, it can no longer be cleaned or purified (the meat). This is the opinion of scholars from madhhab Hanafi except for Abu Yusuf and the opinions of scholars of madhhab Hanbali.
According to scholars of madhhab Maliki, they state that meat cooked with najis, if the najis is cooked with meat before the meat is cooked, then it cannot be cleaned. However, if the najis come into contact with the food after it is cooked, then it can be cleaned. 
Whereas the scholars of madhhab Syafi’I are of the opinion that meat cooked in najis will turn the meat’s inner and outer parts into najis and it can still be cleansed or purified. There are two methods to clean it, that is by washing the meat and then wringing it dry like a carpet. Second, it is conditioned to boil it again in pure water. 
However, al-Khatib al-Syirbini stated in his hasyiah that it isn’t conditioned to wring it regardless of whether it is still with its feathers like a carpet or otherwise. What is stated in al-Raudhah and al-Majmu’ is that meat cooked in najis water will turn the entire meat najis. Hence, it is sufficient by washing (with water) only. Wringing it like a carpet can be understood as a sunnah act or dhaif. Whereas, the opinion of al-Qamuli states that najis that permeates into the meat then it should be removed (the najis) by wringing it out is inaccurate, for the opinion that states that it isn’t conditioned to wring it is more accurate – that is asah – that is built on an asah opinion that the washing water is pure. 
Furthermore, Zainuddin al-Malibari also said that if grains or meat cooked with najis or clothing dyed in najis, then its inner parts are purified by washing its external parts with water on the condition that the to purify the place – the najis part – that is by washing or pouring water at the place of najis. However, if the najis came into contact with a little amount of water and not a lot of water, then, the water changes into najis even if its attributes (color, taste and smell) don’t change. Thus, the water is no longer purifying. 
Likewise, in Hasyiah al-Bujairimi, it is stated that if grains are wet by najis water or urine and ot become wet or damp. Then it is washed with pure water when it is still damp, then its external and internal parts are purified. The same applies to the meat that is cooked with them both – najis water or urine – then washed with pure water, then the entirety of the meat is purified. 
The reason is the purity of something is based on what is apparent (what can be observed) and not what is in the inner parts (cavity/unobservable) as stated by Imam al-Syafi’I when he was discussing the method to clean poison (najis) that has seeped into a heated metal and poured poison on it. 
According to the above arguments and discussion, in our opinion, blanching or boiling chicken that has yet to be cleaned during the process of removing its feathers will turn the chicken and boiling water najis. However, the chicken can be cleaned or purified again of its outer and inner parts by only washing it with pure water as stated by scholars of madhhab Syafi’i. The reason is the purity of something is based on what is apparent – observable – and not what is internal – that is unobservable.
May Allah SWT grant us all a clear understanding in religion. Amin.
 Surah al-Baqarah: 168
 See Tafsir al-Tabari, 3/300.
 See al-Fiqh al-Manhaji, 1/33-35.
 See al-Mausu‘ah al-Fiqhiyyah al-Kuwaitiyyah, 40/91-92.
 Narrated by al-Tirmizi (17); Ibn Majah (314); Ahmad (3685)
 See al-Mausu‘ah al-Fiqhiyyah al-Kuwaitiyyah, 29/116.
 See al-Majmu‘ Syarh al-Muhazzab, 2/599-600.
 See Hasyiah al-Syirbini ‘ala al-Gharar al-Bahiyyah, 1/59.
 See Fath al-Mu‘in, pg. 78.
 See Hasyiah al-Bujairimi ‘ala Syarh al-Manhaj, 1/101.
 See al-Majmu‘ Syarh al-Muhazzab, 2/600.