The hadith you seem to be referring to does not specifically discuss the gradual prohibition of alcohol, but rather that the rules of Islam and the revelation of the Quran occurred gradually so that people were willing to follow and accept them. Alcohol was only mentioned as an example:
Narrated Yusuf bin Mahk:
While I was with Aisha, the mother of the Believers, a person from Iraq came and asked, "What type of shroud is the best?" 'Aisha said, "May Allah be merciful to you! What does it matter?" He said, "O mother of the Believers! Show me (the copy of) your Qur'an," She said, "Why?" He said, "In order to compile and arrange the Qur'an according to it, for people recite it with its Suras not in proper order." `Aisha said, "What does it matter which part of it you read first? (Be informed) that the first thing that was revealed thereof was a Sura from Al-Mufassal, and in it was mentioned Paradise and the Fire. When the people embraced Islam, the Verses regarding legal and illegal things were revealed. If the first thing to be revealed was: 'Do not drink alcoholic drinks.' people would have said, 'We will never leave alcoholic drinks,' and if there had been revealed, 'Do not commit illegal sexual intercourse, 'they would have said, 'We will never give up illegal sexual intercourse.' While I was a young girl of playing age, the following Verse was revealed in Mecca to Muhammad: 'Nay! But the Hour is their appointed time (for their full recompense), and the Hour will be more grievous and more bitter.' (54.46) Sura Al-Baqara (The Cow) and Surat An-Nisa (The Women) were revealed while I was with him." Then 'Aisha took out the copy of the Qur'an for the man and dictated to him the Verses of the Suras (in their proper order) .
(Sahih al-Bukhari)