Dissolve the sugar in about 1 cup of warm non-chlorinated water in a clean glass jar, stirring until completely melted. Add the remaining 3 cups of cool non-chlorinated water to bring the temperature down to room temperature. It's crucial the water is not hot when you add the grains.

Add the active water kefir grains to the sugar water. Optionally, you can add a slice of organic lemon and a piece of dried fruit (like a fig or apricot) to provide additional minerals which can help feed the grains.

Cover the jar with a breathable cloth (like cheesecloth or a coffee filter) and secure it with a rubber band. This allows air to circulate while keeping contaminants out. Place the jar in a warm spot (ideally 68-75°F / 20-24°C) away from direct sunlight.

Allow the mixture to ferment for 24-48 hours. The fermentation time will vary depending on the temperature, the activity of your grains, and your desired taste. Taste periodically; it should become less sweet and develop a pleasant tang, with a slight fizz.

Once fermented to your liking, place a non-metal strainer over a clean pitcher or bowl and gently pour the contents of the jar through it to separate the water kefir liquid from the grains.

Remove any added fruit or lemon from the strained grains. The strained liquid is your finished first fermentation (F1) water kefir, ready for consumption or a second fermentation.

Immediately transfer the separated water kefir grains to a new batch of fresh sugar water to continue the fermentation cycle. If you need to take a break, store the grains in sugar water in a sealed jar in the fridge for up to a week, changing the sugar water weekly.

*Optional Second Fermentation (F2):* For increased carbonation and flavor, pour your strained water kefir (F1) into airtight bottles. Add fresh fruit pieces, fruit juice, herbs (like ginger or mint), or spices. Seal the bottles tightly and let them ferment at room temperature for another 12-24 hours. Be sure to 'burp' the bottles occasionally by opening them slightly to release built-up pressure.

Refrigerate your finished water kefir (F1 or F2) to slow down fermentation and enjoy it chilled. It can be stored in the refrigerator for several days to a week.