I most definitely disagree with the statement that weighing only works for large batches. It's quite the opposite-especially with the tools available to most DIY'ers.
My eyedroppers average 20 drops/ml. That is an average only. It is not even a mean, the number most frequently hit. In other words, I know my average drop will be .05 ml, not more or less, could be a lot more or less.
An eye dropper just does not have the resolution, and each drop could be off by a significant % (20, 50, 70% ?), but if I am mixing up a 100 ml that calls for 3% of something, I know I need 60 drops. My average drop size should work fine to give me what I need.
If I am mixing much smaller amounts, my error could be significant. Typically, when experimenting with new recipes, I try to keep my sample around 3 ml. and using the same 3% that the recipe calls for, I now need .09 ml, but my eyedropper can only give me an average of 2 drops at .1 ml with a lot of potential error in drop size. In other words, I do not have the resolution I need to accurately duplicate the recipe. Not quite true, since I have a base of 2.91 ml and add .09 ml to make up my volume; but let's not complicate issues.
Using volumetric measurement methods, I have only two options: micro pipettes or small syringes with a scale that is small enough to get a reasonable measurement-say down to .1 ml or better. Micro pipettes are expensive and require some skill to use. Syringes are messy and wasteful since you need to hold them upside down and vertically to drive out the air and excess liquid.
As pointed out in another thread, you can get a scale with .01 gm resolution at a very reasonable price. It's easier to tweak recipes since I have yet to follow anyone's recipe exactly. Sometimes that's due to my taste; most of the time it's due to not having the flavorings in my stock or the flavor from another supplier.
