Stevia - Growing and Processing

If like me you need to keep a grip on your weight, but don't like to use artificial sweeteners, you will probably be familiar with stevia, which is a no-calorie sweetener.
For the first time (after several previous attempts) I have managed to grow a decent plant that the snails haven't demolished.
It seems that Autumn, which it is here in New Zealand right now, is the best time to harvest stevia, when the leaves are at their sweetest.

Stevia plant

Last week I picked some leaves, washed them and left them to dry in the kitchen. Today I thought that I would pulverise them to make my own stevia powder - which is something I have been buying as a fine white powder in little plastic bags (sounds suspicious eh). Turns out that this is a very refined product - I don't know how they get it looking like that.
My plan was to grind it up, after snipping with the scissors, with my mortar and pestle.

This wasn't terribly effective, neither was the food processor. I eventually rubbed it to a powder through my sieve. The resulting product is sweet, but grassy smelling.

After this I decided to do some research on the internet. Turns out that a coffee grinder is the way to go for making powder.
What I did find on there were recipes for stevia extract, which I am now having a try at.
There is a good instructional blog here at commonsensehome.com (which looks like an interesting blog worthy of another look).
Basically, it is covering washed and dried stevia leaves with vodka for 2 days, in the pantry, then simmering them for a while to reduce the alcohol and liquid to concentrate it.

stevia leaves in vodka - making stevia extract.

I have a plan to make a plastic mesh insert to keep the leaves under the vodka.
I'll report back on result of taste and effectiveness.