Prosecco for a spritz
Buy a cold, dry prosecco. The spritz will not rescue a sweet or warm bottle.
Brut and Extra Dry
Prosecco sweetness labels are easy to misread. Brut is the drier one, up to 12 grams of sugar per litre. Extra Dry is sweeter than Brut, roughly 12 to 17 grams. Dry is sweeter still. For a spritz, start with Brut so elderflower or bitter orange does not pile sugar on sugar.
Extra Dry is a fair second choice in a bitter spritz if Brut tastes sharp to you. It is a worse choice under limoncello, which is already sweet.
What to skip
Skip dessert sparkling wine, anything warm, and any bottle that has been open since yesterday unless it still tastes lively. A spritz is mostly this wine. A cheap brut that is cold and fresh beats a fancy bottle that is flat.
Prosecco DOC is enough. You do not need a prestige cuvée to pour over ice and soda.
Other bubbles, and no bubbles
Another dry sparkling wine will make a spritz. It is just not a prosecco spritz. Still white wine is its own recipe, and often the right one with dinner. Alcohol-free bubbly has to be dry, or the virgin recipes fall apart.
If you are holding a bottle and want food for it, that is a Gastrona question, not a ratio question. Scan the label or match the dish there. Come back here for the glass.
Questions people ask
What prosecco is best for a spritz?
A cold prosecco brut. Extra Dry is a bit softer and a bit sweeter. Avoid sweet sparkling wine.