Italian sparkler (4)
I believe the answer is:
asti
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">italian sparkler</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for asti that I've seen before include "18" , "It's a (anag) - wine" , "Source of fizz" , "Bubbly wine" , "Piedmontese white wine" .)