Originally Posted by apraetor
As for the concentration to use, the directions say 1 to 2 fluid ounces per gallon; 2 tablespoons (tbsp, not tsp) make 1 ounce -- so it calls for 2-4 tablespoons per gallon.
Actually the directions are 1 ounce by weight, not 1 fluid ounce.
I found this e-mail response from Five Star on another forum.
"You are correct! All our powders have recommendations by weight, whereas our liquids are by volume. We find that one gently rounded teaspoon of PBW is about 1 oz by weight. If you have a small postal scale in your home office, as many do, you can verify a convenient measuring device in your home. There are 3 US Teaspoons per 1 US Tablespoon. Thus, about one-third of a tablespoon is about one ounce.
Also keep in mind that in our Five Star Homebrewer Cleaning and Sanitizing kits we pack about 2.25 oz per packet and instruct that to be added to 5 gallons of warm water. That is as low a concentration as 0.4 oz per gallon and is quite effective. In other words, for the home brewer, a little less is better than a little more to control your costs with PBW while still getting 'er done.
Five Star Chemicals
Commerce City, CO"