Hello David. To give you a straightforward answer, doing a direct 1:1 substitution of 750 ml of artisanal mezcal in place of blanco tequila will completely alter the profile of your cocktail, and in most cases, the intense smoke and earthy agave notes will overwhelmingly dominate the other ingredients.
Artisanal mezcal carries complex phenols, smoke, and vegetal qualities that unaged blanco tequila simply does not have. Freezing the batch at sub-zero temperatures actually dulls perceived sweetness and volatile citrus aromas while leaving heavier smoky notes prominent once the drink begins to warm in the glass. While the alcohol and sugar content will keep the batch stable and safe from spoiling over four weeks in airtight glass, the flavor balance will tilt heavily toward smoke if you use 100 percent mezcal.
If you want the cocktail to remain balanced and reminiscent of the original tequila recipe, the ideal approach is a split-base method. Instead of using 750 ml of mezcal alone, consider blending 250 ml of mezcal with 500 ml of blanco tequila, or at most a 50/50 split of 375 ml mezcal and 375 ml blanco tequila. This introduces the depth of artisanal mezcal without masking your citrus and modifiers.
If purchasing additional tequila is not an option and you must use only what is in your pantry, you should prepare the batch with the understanding that this is now a dedicated mezcal cocktail rather than a tequila drink. In that scenario, keep the 750 ml volume to maintain your batch ABV for proper freezer consistency, but taste a single-serving test build first to see if you need to slightly increase your sweet or citrus components to balance the aggressive smoke.
To batch properly for four weeks of freezer storage, combine your ingredients thoroughly, measure out roughly 20 to 25 percent water dilution if you plan to pour directly from the freezer without shaking over ice, funnel into airtight glass containers leaving an inch of headspace, and seal tightly. Best of luck with your batch.
