Volumetric vs mass measurement & storing ingredients in solution


#1

I’ve been using a mostly food based version for a few months now. So far so good.

I have a few ingredients (table salt and choline bitartate) that I add in chemical form in relatively small quantities. I have some scales that apparently are accurate to 0.1g but I don’t really trust them. I’m thinking about pre-disolving 100g of salt (say) in 1L of water and simply pipetting the required amount as i make each meal. A quick time in motion study of me pipetting vs measuring the weight of each would save ~1 minute per meal (which is about 25% of total time spent preparing, consuming and cleaning up after myself). My questions are:

  1. Are there any issues with storing chemicals dissolved in water in
    the long term (e.g. >2 months)? It will be in an airtight, dark
    bottle. I cannot imagine any issues with the salt solution, but am
    not sure about the choline bitartate.
  2. Are there any chemists who could tell me if both chemicals would react with each other if I stored them both in the same solution? (i.e. so I only have one liquid to pipette rather than two). When i mix the two together i cannot see anything happening (no effervescence, etc) but that doesn’t mean there is no reaction.
  3. I anticipate the error in the measurement using pipettes will be smaller than i currently have weighing the ingredients (see here for an explanation). Is anyone aware of any potential risks with accuracy using this approach?

Thanks!


#2

I don’t know about the water and pipetting, but what I do is weigh out the different ingredients based on specifically defined volumes, and then just those volumes as my measurement, rather than weighing every day.

For example, my choline for approximately 1.1 grams is 1/32 of a teaspoon. I think it averaged out to 1.04 grams, but close enough. So then I just use 1/32 teaspoon for my choline.
For my salt it is 1/8 teaspoon per day.

This is what I use to measure volume with:

It goes down to 1/64 of a teaspoon, which takes care of 90% of all of my ingredients.


#3

You should test your pipette’s markings are accurate by repeatedly transferring water from a glass into a measuring jug - say, 100 times. Divide the volume the measuring jug shows by 100 and compare. Remember to measure from the bottom of the meniscus.


#4

@HarveyDesu Those little spoons come pretty close to what i want. I’ve got something similar for now, but i’m hoping for something more accurate in the long run - i had a play and found that measuring by volume seems to result in a mass fluctuation +/- ~20% (is it my technique or just the nature of the way the particles pack together?). This isn’t a huge issue WRT overdosing (it should average out), but does seem to affect taste quite a bit (especially since I’m talking about salt and choline).

@richardtkemp Thanks for the tip!

Anyone got any thoughts on whether storing in solution would work? I’'ll give it a go and see…