It is disliked to breathe into the vessel, and it is recommended to take three breaths, outside the vessel
وَحَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، وَأَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ قَالاَ حَدَّثَنَا وَكِيعٌ، عَنْ عَزْرَةَ، بْنِ ثَابِتٍ الأَنْصَارِيِّ عَنْ ثُمَامَةَ بْنِ عَبْدِ اللَّهِ بْنِ أَنَسٍ، عَنْ أَنَسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَتَنَفَّسُ فِي الإِنَاءِ ثَلاَثًا .
Anas reported that Allah's Messenger (ﷺ) used to breathe three times in the course of a drink (i. e. he drank in three gulps).