Colin Webb from New Zealand had some very interesting thoughts to add to the discussion of using milk powder afloat…
Hi Lin And Larry
Firstly some of my background is an industrial chemist and during my working life I owned a dairy factory producing milk powder from fresh milk for over 15 years. I sold this to Fonterra in 2006. So I will tell you how it works, but firstly be aware that most fresh milk in S.E Asia is from reconstituted milk powder, and for the average discerning person they would not know the difference from fresh milk.
The process or reconstituting the powder is: first weigh the powder and add at 125 grams of powder per litre of good drinking water. Max temp for the water 35C then refrigerate. Cold water is ok but the rest time takes longer.
Add the instant milk powder ( prefer the instant milk as it gets through the first stage quicker but either instant on non- instant is ok, just good quality – ie buy Nestle , Fonterra , Murray Goulburn etc as there are many rascals blending some slightly off spec product to make a quick $ – especially in NZ )
Stages of reconstitution
1. Add the powder to the water. What happens first is there is a change taking place where the powder air inter face of the milk powder partials changes to powder water infer face on the surface of the powder. Just give it a light stir to disperse
2. Most of the powder will sink, however for instant powder the powder has a coating of lecithin on the surface the change from air powder to water powder happens more quickly. Give this a few minute or even 30 min , it is not specific but then give it a light stir fir a few seconds.
3. at this stage the outside of the milk powder particle is wet but the inside of the particle is still dry powder, so if you then use the made up milk it will have a taste component of part of the dry internal powder of each particle. The particles are microscopic but anyone can taste that this was made up from milk powder
So what needs to happen in this 3rd stage is , you need time for the water to soak into the powder particle and disperse the particle. When this final dispersing has happened the milk will taste like fresh milk.
So put it in the fridge for 4 hrs rest time, or make it up the night before, and you will get a great result. Please note that when made up the shelf life of the new liquid milk is roughly the same as fresh milk and not longer
Best of luck