Thoroughly sanitize all equipment that will come in contact with your cider. This includes fermentation vessels, airlocks, siphoning tubes, and bottles.
If using unpasteurized cider, add a crushed Campden tablet and let it sit for 24 hours to kill wild yeast and bacteria. For store-bought pasteurized cider, skip this step, but warm the juice to room temperature (65-75°F/18-24°C).
In a small, sanitized bowl, activate your yeast according to package instructions. Typically, mix the yeast with warm water (95-105°F/35-40°C) and wait 5-15 minutes until frothy.
Transfer your apple juice to a primary fermentation vessel. Add the yeast nutrient, pectic enzyme, and acid blend if using. Pour in your activated yeast and stir gently to distribute evenly. Seal with an airlock and store in a cool, dark place (60-70°F/15-21°C is ideal).
Allow the cider to ferment for 10-14 days, or until bubbling slows to less than one bubble per minute. The specific gravity should drop from around 1.050 to near 1.000.
After primary fermentation, gently transfer (siphon) your cider to a bottling bucket, leaving the sediment behind. Add your priming sugar (3-4 tablespoons of honey or 1/4 cup of brown sugar per gallon). Stir gently but thoroughly.
Fill sanitized swing-top bottles or capped beer bottles, leaving about 1 inch of headspace. Seal tightly.
Store the bottles at room temperature for 7-14 days to allow carbonation to develop, then transfer to refrigeration to stop fermentation and clear the cider.