I use the same recipe but found a few tricks on various websites. First, I boil the water before adding it to the bottle. I also let the bottle cap float in the boiling water. You of course let the water cool to room temperature before proceeding. This sterilizes everything and supposedly helps. Next, instead of just dumping the yeast and sugar into the bottle I combine the yeast, a small amount of water, and a pinch of sugar in a small bowl. I stir this up with a fork making sure I make bubbles, thus forcing air into the mix. I let this sit for 10 minutes before adding it to the bottle. This gives the yeast a bit of a head start, if you will.
2 cups table sugar, 1/2 tsp of left-over bread machine yeast (I have a huge bag of it, allegedly expired 2 yrs ago), 1/4 tsp Nottingham ale yeast, a "slurp" (1T?) of blackstrap molasses, all in 2-liter bottle, filled to where it starts to narrow at the top.
Once I run out of bread machine yeast, I'll go back to just ale yeast. This recipe lasts three weeks easy. I've seen a leftover bottle still going after five weeks, but wouldn't trust it on the tank for that long - when it quits, it quits *thud*. The bread yeast helps it get rolling in 12 hours instead of 24.
I use a little pyrex bowl (maybe 1 cup?) for starting the yeast. I start by sterilizing the bottle with about 1/8 tsp B-Brite (available at any homebrewing shop) and rinsing well. Then I take some of the treated water from my treatment trashcan and nuke it to 125F or so (just too hot for comfort). I put the sugar, water, and molasses in the bottle and shake it well (until it turns clear). By that time, it's cooled a good bit. I wait 'till it's just below 104F, then put about 1/2c in the bowl, add the yeast to the bowl, and stir the bejabbers out of it with a fork. Let it sit for 10-15 minutes to get rolling, pour it in the bottle, slap a cap on it, and shake it hard to heavily oxygenate the mix. Then I loosen the cap and just leave it perched on top of the neck to keep the airborne ickies out. As I say, with the bread machine yeast this blend gets cranked in 12 hours; with just the ale yeast, 24 hours is required. With the ale yeast, it'll keep working well when the house gets down into the mid-60s (that's why I like it), and really blasts when it's warmer. I use a two-bottle setup, and change alternate bottles every week - though it will run well longer, if needed. I lean a bit over-cautious, and it's cheap!