Pour your cold water into the plastic bottle, leaving about an inch of air at the top. Now, add that half teaspoon of sugar. Don’t add more—your water isn’t making a cake. The yeast just needs a tiny snack to get excited.
Screw the cap on tight, and shake the bottle like you’re a bartender at a tropical resort. You want the sugar to dissolve completely. This is the only time you’ll look cool doing this—embrace it.