I made 2 growlers of root beer and it tastes awful I used 1 cup of sugar 1/4 tsp of bakers yeast and 1tbsp of McCormick root beer concentrate in each growler what happened ?
Define awful. And check other threads of this type.
One definate problem is that you used bakers yeast. That's said to leave a yeasty taste since the strain is for bread where you want a yeasty taste. Use a brewing yeast. I believe Yoop recommends a champagne yeast for it's clean taste.
Or use a co2 tank and force carbonate things.
Was it sweet enough. Does mccormick have the right flavor for a drink? (test this by using plain soda water from the store if you have to)
I think McCormick's is ok. I've used it, and it's not the world's best root beer but it's pretty good. The champagne yeast will really make a big difference.