Makes 1 gallon 

What You Need

Ingredients 
1 gallon apple cider or apple juice
1/4 teaspoon dry champagne yeast or baker's yeast (see note)

Equipment
Measuring cup
Fork or whisk
Small funnel
2 two-liter soda bottles, 4 one-liter soda bottles, or 7 sixteen-ounce swing-top bottles with 1 sixteen-ounce soda bottle (see note)

Safety First!

• Clean Your Bottles and Equipment: Wash all your equipment and bottles with soap and water, and thoroughly rinse. It's not necessary to sanitize equipment for this mini-brewing project, but cleanliness is still important.

• Use Bottles Meant For Carbonation: Only make sparkling cider in bottles intended for carbonation. Soda bottles and glass swing-top bottles are specifically designed to withstand the pressure of carbonation. Other bottles, even the original container the cider came in, can break or shatter under the pressure.

• Refrigerate When Carbonated: Refrigerate the sparkling cider as soon as the plastic bottles feel rock-solid to the touch. Refrigeration puts the yeast on hold and prevents the cider from over-carbonating. There is some margin for error here, but left un-refrigerated, the pressure will continue to build and the bottles will eventually break.

Instructions

1. Dissolve the Yeast: Pour a half cup or so of the cider into a small measuring cup. If the cider is cold, warm it in the microwave in 5 second bursts until it feels lukewarm to the touch. Add the yeast and stir to dissolve completely. (If you're not sure your yeast is still active, let this solution stand until you see small bubbles collecting on the surface of the cider.)

2. Pour the Yeast Back into the Cider: Pour the dissolved yeast back into the container of cider. Seal and shake to thoroughly distribute the yeast.

3. Divide the Cider Between Bottles: Insert the funnel into the mouth of one of your bottles. Fill with cider, cap, and label with the date. Repeat with your remaining bottles.

NOTE: If you are bottling in swing-top bottles, also fill one plastic 16-ounce (or smaller) soda bottle. Since it's hard to tell when cider in glass bottles are fully carbonated, this soda bottle will serve as your indicator.

4. Let the Cider Carbonate: Store the bottles of cider somewhere dark and at room temperature to carbonate. The cider is carbonated when the plastic bottles feel rock-solid to the touch. This will take about 24 hours at an average room temperature of 70°F-75°F; the cider will carbonate more quickly at warmer temperatures and more slowly at cooler temperatures.

5. Refrigerate the Cider: Refrigerate the cider as soon as it is fully carbonated. Refrigerate for at least 6 hours before serving, or for up to two weeks. Open bottles very slowly over a sink in case the cider gushes. Refrigerate any cider that isn't consumed after opening.