Short answer
Yes, it is makruh (disliked), not haram. The Prophet ﷺ forbade breathing into a drinking vessel or blowing into it, and scholars apply this to hot food as well. Let the food or drink cool, stir it, or pour it into another cup instead.
Blowing into food or drink is makruh tanzihi (mildly disliked). It is not a sin, and the food stays halal.
The four schools agree on this.
Explanation
This is one of the manners of eating and drinking taught in the Sunnah. The Prophet ﷺ forbade breathing into the vessel and blowing into it. When a man said he sometimes saw a speck in his cup, he told him to pour that bit away; and when the man said he could not drink in one breath, he told him to move the cup away from his mouth to breathe.
Scholars give several reasons: breath can carry germs and smells into what you or others will drink, it is unpleasant for people sharing the food, and it is poor manners. The four schools agree that it is disliked.
What to do instead:
- wait a little for hot tea, coffee or soup to cool;
- stir it, or pour it between two cups;
- eat from the cooler edges of the plate first, since the Prophet ﷺ taught eating from the sides because blessing comes down in the middle;
- take the cup away from your mouth to breathe, and drink in three breaths.
Because it is only disliked, do not be harsh with others, especially children, who do it. The full manners are in sunnahs of eating and the sunnah way of drinking water.
The evidence
Sunan Abi Dawud 3728
Grading to be checked... نهى أن يتنفس في الإناء أو ينفخ فيه ...
"The Messenger of Allah forbade breathing into the vessel or blowing into it."
The direct prohibition on blowing into food and drink.
Jami' at-Tirmidhi 1887
Grading to be checked... نهى عن النفخ في الشرب ...
"He forbade blowing into a drink."
The same manner, with practical advice on what to do instead.
Jami' at-Tirmidhi 1805
Grading to be checked... البركة تنزل وسط الطعام فكلوا من حافتيه ...
"Blessing comes down in the middle of the food, so eat from its edges."
Eating from the edges, which also lets hot food cool.
Where the ruling is recorded
- al-Fatawa al-Hindiyya, Kitab al-Karahiyya, chapter on eating and drinking. Blowing into food and drink is disliked.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.