Peel about 2 inches of ginger and grate with the microplane until you get 2 Tablespoons.

Bring 1 cup of water to a boil in small sauce pan. Add sugar and stir until dissolved. Remove from heat and add ginger and salt. Let cool and add lemon juice.

With the kitchen funnel pour ginger water into the 2 liter bottle along with the remaining water. (save empty bottles/lids for refilling when ginger ale is ready to be bottled). Leave a 1-2 inches head space.

Add yeast. Screw on cap tightly. Gently roll bottle. Do not shake and let bottle sit at room temperature on the counter out of direct sunlight for 2-3 days until desired carbonation reached. Notice when cap is applied tightly how the bottle has some flexibility? Every day you need to check the bottle for firmness. If it is firm and sometimes hard as a rock carefully burp the bottle (slowly open container to let gasses out and then re-close tightly). Check the bottle every day to remove excess gas/pressure from the bottle. If you don't you could have a sticky mess on your hands.

Once you have reached the desired carbonation you can 1) place the 2 liter bottle into the refrigerator or 2) using the kitchen funnel fill the four empty 16-ounce bottles with ginger ale and then store in refrigerator or 3) put in Swing Top Glass Bottles and store in refrigerator.