I've been carbonating with the "Ross Method" (ramp up pressure, shake keg for a while, you can find it explained in a ton of places on this forum) for inexact results for years now, and I hadn't thought of using a set of scales to add precision before today, and I can't find any information about others doing it so I thought I'd share. I have a set of rather precise (1g) scales that are good up to 40kg that I use for all my grain measurements. Carbon Dioxide has a density of approximately 2g/L (1.96 precisely). If you want to carbonate beer to 2 volumes, then you want to have 2 x 2 = 4g/L of CO2 in your beer. For a 19L keg, this is 76g. You can probably see where I'm going with this. 1. Tare scales with full keg 2. Shake keg for a minute or so 3. Weigh keg to see how much CO2 you just added 4. Repeat steps 1 - 3 until you hit 76g (or whatever desired weight is based on how many vols you want) 5 (Optional) give beer a couple of hours to settle before drinking (yeah, right...) I realise not everyone has a set of scales to do this, but for those who do, enjoy. Feel free to critique my calculation/method.