Mix this up at least 4 hours before you want to use it. It needs time to absorb fully first.
First, put your hyaluronic powder in your sterilized glass jar.
Next, add the hydrosol (or distilled water--do not use filtered tap water--it may introduce harmful microbes to your serum). Put the lid on and give it a good shake.
Then, remove the lid, and add the glycerine and Luecidal Liquid preservative if using). If you aren't using the preservative, it is a good idea to just make a half batch to make sure you use it all up within a few weeks. Also be sure to refrigerate your serum if not using a preservative. If you do use the preservative, you can store your serum for a few months at room temperature (even longer in the fridge).
Put the lid on the jar and shake, shake, shake. The mixture will be lumpy with pockets of powder. Do not fear! It will fully absorb.
Finally, refrigerate your serum while you wait for it to fully hydrate-about 4 hours.