Heat some water and dissolve the sugar in it.
Cool the water-sugar mixture up to room temperature.
Add the hydrated grains.
Cover the jar with a paper towel or a cheesecloth, secure with something so that the cover won't fall off.
Let sit (preferably at 70-75°F) for 24-48 hours.
When ready, strain the grains through a colander and pour the liquid into another jar.
You can use the grains again, just make sure they are washed thoroughly.
To make the water kefir carbonated, pour a couple ounces of fruit juice such as grape, pomegranate, apple, or cherry into the water kefir you just strained.
Once you've added the juice, cover the jars tightly with an airtight lid and leave for additional 1-3 days.