Sayyiduna Anas (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) forbade "mixing unripe dates and ripe dates to make nabidh and then drinking it", because when wine was forbidden, this was the common wine of the people.
This hadith shows that the reason for its prohibition is that it is khamr (wine), and khamr is everything that covers the intellect. On the basis of these narrations, it is recommended to avoid making nabidh by mixing them even if no intoxication has arisen in them, because the reports prohibiting it without qualification are established, and they are more firmly established than the reports of permissibility.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأشربة والحد فيها / 17465