The Prophet ﷺ forbade the mixing of ripe and unripe dates and also the mixing of dates and raisins (for preparing a syrup) but the syrup of each kind of fruit should be prepared separately. ( One may have such drinks as long as it is fresh )
نَهَى النَّبِيُّ ﷺ أَنْ يُجْمَعَ بَيْنَ التَّمْرِ وَالزَّهْوِ وَالتَّمْرِ وَالزَّبِيبِ وَلْيُنْبَذْ كُلُّ وَاحِدٍ مِنْهُمَا عَلَى حِدَةٍ