Reference for Bava Batra 251:8

רב פפא משמיה דרבא אמר ויתר באותה שדה קא סבר אין לו לבכור קודם חלוקה (ומה דאתא לידיה אחיל אידך לא אחיל)

[or] olives which they plucked, the firstborn receives a double portion even if they pressed [the grapes]. '[If] they pressed [the grapes]', it was asked, '[were these not] first grapes [and] now [they are turned into] wine?'<span class="x" onmousemove="('comment',' Since this is a case of complete transformation. why should he receive a double portion? v. p. 522. n. 9. and n. 10. ');">¹⁵</span> [To this] R. 'Ukba b. Mama replied. 'Compensation is paid to him for any damaged grapes.'<span class="x" onmousemove="('comment',' The firstborn receives a double portion. not in the wine, but in value of the grapes that were lost or damaged in the process of the manufacturing of the wine. The heirs, who made the change in disregard of his protest, must hear the loss. ');">¹¹</span>

Jastrow