All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
The mentioned hadeeth does not indicate that Muʻaawiyah drank alcohol. Allah forbids that he does! Had he drunk it, Buraydah would not have sat at a table where alcohol is drunk, and he would have left the place.
The hadeeth was cited by Imaam Ahmad in his Musnad as follows:
“Zayd ibn Al-Hubaab narrated from Husayn that ʻAbdullah ibn Buraydah said, ‘My father and I entered upon Muʻaawiyah, so he made us sit on a mattress; then we were brought food and we ate, then we were brought a drink, and Muʻaawiyah drank and then offered the drink to my father. Then he (meaning Muʻawiyah) said, 'I never drank it since the Messenger of Allah, sallallaahu ʻalayhi wa sallam, prohibited it.' Muʻawiyah then said, 'I was the most handsome young man in Quraysh with good front teeth. And there is nothing which I find as enjoyable as I used to find it when I was young except milk or a person with whom I have a good conversation.'’”
Shuʻayb Al-Arnaa’oot said:
“Its chain of narration is strong. Husayn was nicknamed Ibn Waaqid Al-Marwazi, and his narrations were cited by Abu Daawood, An-Nasaa’i, At-Tirmithi, and Ibn Maajah. His narrations in Saheeh Muslim are cited as supportive evidence to other narrations with the same chain of narration, and his narrations in Saheeh Al-Bukhaari are reported as a Mu’allaq hadeeth, i.e. a hadeeth whose whole chain of narrators is omitted. He was a sadooq reporter (an honest reporter who may make mistakes). The rest of the narrators of this hadeeth are trustworthy who are cited in Saheeh (sound) Hadeeth books ... The statement, ‘And I have not drunk it since the Messenger of Allah, sallallaahu ʻalayhi wa sallam, prohibited it’ was said by Muʻaawiyah ibn Abi Sufyaan, and perhaps he said so when he saw disapproval in Buraydah's face for (mistakenly) thinking that it was a prohibited drink.”
This makes it clear that the one who said 'I never drank it since the Messenger of Allah, sallallaahu ʻalayhi wa sallam, prohibited it.' was Muʻaawiyah, and not Buraydah, in order to dispel what Buraydah might think that this drink was alcohol. So Mu’aawiyah said that he never had it (alcohol) since its prohibition was revealed; rather, he mentioned that he enjoyed milk just as he used to enjoy it when he was a young man in Makkah (i.e. what he actually drank was milk and not alcohol).
Even assuming that it was Buraydah who made that statement, then it is possible that what Mu‘aawiyah was drinking was Nabeeth (water in which dates or grapes or other fruit was soaked) that did not intoxicate; i.e. was not fermented to the extent of causing intoxication. Buraydah chose not to drink it to avoid a doubtful matter. Many scholars held that it is permissible to drink Nabeeth provided that it did not reach the extent of causing intoxication. An-Nawawi said about Nabeeth, “The view of our school as well as that of the majority of the scholars is that it is permissible to drink it unless it has become intoxicating, even if it was left soaking for more than three days (and has begun to ferment, which is the start of the alcohol brewing process).”
He added, “Our evidence is the hadeeth of Buraydah in which the Messenger of Allah, sallallaahu ʻalayhi wa sallam, said, ‘I had forbidden you from making Nabeeth except in a waterskin. But now you may make it in all vessels, but do not drink an intoxicant.’ [Muslim] This report is of a general indication and includes the Nabeeth that was left soaking for more than three days. There was no reported forbiddance about the Nabeeth that was left soaking for more than three days. Accordingly, this entails deeming it allowable as long as it has not become intoxicating.”
Allah knows best.