I'm not sure if this is an original idea; I highly doubt it given how obvious it is yet I can't recall seeing this suggestion here before. I'm getting into freezer bag cooking and so need to be able to measure liquid volumes in the backcountry to the nearest fluid ounce. My BPL Ti cup only has two graduations which makes it useless for that (thanks Evernew!) and my water boiler is a heiny pot. It occurred to me last night that I could simply graduate my water bottle since I prefer it to a platy bag for its miniscule weight.
I happen to have a 2 fluid ounce syringe which made it quick and easy. In order to be as precise as possible and not amplify error, I tared the empty water bottle on my gram scale and filled by weight rather than trusting the syringe. A fluid ounce of tap water will weight 29.5 grams so fill to 30 and then 29 on a gram scale. Rinse and repeat; no amplified error.
Graduated Absolutely Lightest Water Bottle
Turns out my 1L water bottle actually holds 35 fluid ounces when filled to the bottom of the neck. A bonus fluid ounce! So 15 minutes yielded a means of accurately measuring water volumes which added 0 grams to my pack. I had previously added Aquamira instructions to the outside of the water bottle to reduce the chance of my making a mistake in the backcountry.
