Hi, When I estimate the amount of priming sugar I need for bottling I usually check a number of online calculators, including the Brewer's Friend one (also the ones at Northern Brewer, Beersmith, Tastybrew, Beer Recipator, and others). Apparently the formulas behind the calculators vary, since the weight of corn sugar required for a given batch size, temperature, and desired CO2 level varies among the individual calculators. The Brewer's Friend one always recommends the greatest amount of sugar--meaningfully more compared to, say, Beersmith and Tastybrew. For example, for a 5.25 gal batch, 68 degrees F., 2.5 vols of CO2, the BF corn sugar weight is 5.00, while Beersmith's is 4.61 and Tastybrew's is 4.60--actually quite a range. Anyone have any thoughts as to who to trust more? Of course my natural inclination is to experiment and see which one gives me the best results, but since I almost never brew the same recipe twice I don't have a consistent base to assess one calculator over the other. Anyone have the same problem, or have you all just used one or the other calculator on faith? (I won't even get into the issue of what temperature is really right to enter into any of these calculators--highest fermentation temp of the beer, the bottling ambient temperature, or what--that's a real mess and I can't believe there's complete disagreement about that in the brewing community, considering that's a basic thing with important implications to getting the desired carbonation levels).