The Aperol Spritz is the exception to the batching playbook. Two of its three ingredients — Prosecco and soda water — are carbonated, and carbonation does not survive batching: the bubbles dissipate in the bottle and the drink reads flat within an hour. So a Spritz pitcher is honest about what it is: a same-hour pitcher for table service, mixed the moment the table sits down, poured before the bubbles have anywhere to go.
What you can't batch
You can pre-batch the Aperol portion indefinitely — Aperol is shelf-stable for years and pre-portioning it into 2 oz pours is reasonable bar prep. What you cannot do is pre-mix Aperol with Prosecco and store the result; within an hour you'll have a flat orange beverage that tastes like dull jam. The bubbles in a Spritz are not a garnish, they're a structural element.
The 3:2:1 ratio
Three parts Prosecco, two parts Aperol, one part soda water — the IBA spec, and the one Padua and Venice serve. At pitcher scale: 24 oz Prosecco (one full 750ml bottle), 16 oz Aperol, 8 oz soda water. Eight serves at 6 oz each. The pitcher must be cold; ice in the pitcher dilutes too aggressively, ice in the individual glasses does not.
Build and pour
Combine all three components in a well-chilled pitcher just before service. Stir gently with a long spoon — you're integrating, not aerating. Pour 6 oz over ice in a large wine glass; garnish with an orange slice and (optionally) a single fat green olive in the Venetian style.
The pitcher holds for about an hour at room temperature with the bubbles meaningfully intact. After that, mix a new one. For a long event, refresh the pitcher each round rather than building a larger one.