Place the sugar, raisins and lemon slices (or juice and zest) in a quart mason jar. Pour near boiling water over the top to fill the jar to within 1 inch of the top. Stir to dissolve the sugar or honey.

Allow the mixture to cool to room temperature, and then add a pinch of yeast. Stir to incorporate.

Seal the jar with a mason jar airlock (or cover loosely with a cloth if you don't have an air lock). Allow the mixture to ferment at room temperature for 24 to 48 hours, until the raisins float to the top.

Once the raisins float, pour the sima through a fine mesh strainer and bottle in flip-top Grolsch bottles or another mason jar. Seal the lids tightly and store in the refrigerator.

Allow the drink to age in the refrigerator sealed for 2-4 days to accumulate carbonation. The tight seal is what allows the drink to carbonate. If you find it's not carbonating in the refrigerator, leave it out on the counter for a few hours to carbonate (but watch the time there, leaving it out too long will cause too much pressure to build up, and it may break the container).

Keep the drink stored in the refrigerator to slow fermentation until you're ready to drink. Open it when you're ready to consume, but be sure to drink within seven days for best results.