Answer: In the name of Allah, Most Compassionate, Most Merciful,
Assalam’aleykum, I pray this finds you in the best of states.
Jazakum Allah khayr for your question!
It is not a must to say the basmallah before every sip.
Among the Prophetic sunnas related to drinking are:
a) Beginning in the name of Allah, by saying Bismillah or Bismillah ar-Rahman ar-Raheem. Some extended this to every sip;
b) Drinking with one’s right hand, because it is disliked to drink with one’s left hand unless there is a genuine excuse;
c) Drinking between three breaths;
d) Not breathing into one’s drink;
e) Not drinking while standing;
f) Drinking in sips rather than gulps, for the latter is disliked;
g) Not drinking excessively. The sunna is to eat and drink in moderation, such that it does not lead to harm or laziness that prevents one from worship.
h) Praising Allah after drinking, by saying Alhamdulillah (‘All praise is to Allah’) or any of the sunna invocations after drinking, such as Alhamdu liLlahi lLadhi at`amana wa saqana wa ja`alana muslimeen]
’.All praise is to Allah who has fed us and given us drink, and made us of the Muslim‘
And Allah knows best. I hope that the above answers your question. If something is unclear please do not hesitate to ask again.
May Allah Most High grant you the best of this world and the next. Please keep us in your du’as!
[Ustadh] Sufyan Qufi