Case Study: Specific Gravity Values for Liquids

Our client, a mixologist, approached us because she wanted to state the energy values for her cocktails and wished to put the values on her menu per 100ml rather than per 100g.

Working out an accurate specific gravity value for a liquid can be a challenge at the best of times and especially where there are both liquids and solids within the recipe.

In this case, our client had syrups, fruit and ice cubes going into her drinks and was very uncertain as to how to approach the measurements.

We were able to help and explained that there are a few things to bear in mind to ensure accuracy:

1. Make up several batches as this will ensure you obtain a good sample, enabling you to cover any small inconsistencies/differences for the fruit, ice cubes etc. (Much easier to demonstrate due diligence this way too)
2. Reduce everything to a liquid form before measuring the volume i.e. allow ice cubes to melt, blend everything etc. (even though the cocktails are not sold this way)
3. Use a quality measuring cup to measure out several cups of the liquid, ensuring that the cup is level and the liquid is right to the top of the cup
4. Using quality digital scales, place an empty bowl onto the scales and set the scales to zero.
5. Pour the measured liquid from the cup into the vessel on the scales
6. Make a note of the weight of the liquid and the volume of liquid weighed
7. Divide the weight value by the volume value and enter that value into the ‘details’ area of the recipe under the ‘specific gravity’ tab. So for example if 100mls juice weighs 104grams, the SG entered should be 1.04

It doesn’t matter whether the product is sold with solid ice cubes and pieces of fruit, the need to reduce these to a liquid is simply to remove the gaps that would be there if you didn’t.

Our client was very happy to have gained both the understanding and the ability to offer per 100ml reports on all of her cocktails!