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I have grown and dried about a pound of the herb called 'stevia' or
'sweetleaf'.  I would like to find out how to make a liquid extract from it
that is CLEAR, like the storebought extract with the brand name
SteviaClear (among others) which succeeds in eliminating the musty aftertaste.

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In one recipe I found, fresh rather than dried leaves seem to be
recommended for making an extract. In the second, alcohol is used to
draw out more of the herb's sweetness. (That recipe also seems to
suggest the use of fresh leaves, but not as clearly.) I don't known if
either of these methods might help diminish or remove any
mustiness/aftertaste.

Crushing the dried leaves is the final step in releasing stevia's
sweetening power.  This can be done either by hand or, for greater
effect, in a coffee grinder or in a special blender for herbs.  You
can also make your own liquid stevia extract by adding a cup of warm
water to 1/4 cup of fresh, finely-crushed stevia leaves.  This mixture
should set for 24 hours and then be refrigerated.
http://www.stevia.net/growingstevia.htm

A liquid extract can be made from the whole Stevia leaves or from the
green herbal Stevia powder. Simply combine a measured portion of
Stevia leaves or herbal powder with pure USP grain alcohol (Brand, or
Scotch will also do) and let the mixture sit for 24 hours. Filter the
liquid from the leaves or powder residue and dilute to taste using
pure water. Note that the alcohol content can be reduced by very
slowly heating (not boiling) the extract and allowing the alcohol to
evaporate off. A pure water extract can be similarly prepared, but
will not extract quite as much of the sweet glycosides as will the
alcohol. Either liquid extract can be cooked down and concentrated
into a syrup.
http://www.stevia.com/SteviaArticle.asp?ID=2269

interesting, thursdaylast23-ga, thanks a lot!

I would tend to try vodka because I really don't like the taste of
brandy or Scotch - vodka is relatively tasteless, and I do hope I can
evaporate off the alcohol without altering the taste of the stevia too
much.  Have you actually tried this?  Does the end result turn out
clear or colored?   Another good experiment will be using the dried
herb vs the fresh leaves (can't do the latter until this summer,
anyway)

thanks for your tips!

ts 

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timespacette,

Back in the sixties, I had a college chum who made his own herbal
tinctures from various substances. To remove unpleasant tastes, he
filtered the extracts through activated charcoal. I have no idea
whether that is feasible with stevia, but I thought it would be worth
mentioning.

No, I can't speak from personal experience on this one. (As a guess,
I'd expect you'd be more likely to get a clear[er] extract from fresh
leaves than from dried ones.) I did find a scientific article that
analyzes the various commercially used methods of clarifying the
extract. It is a little like Greek to me, with all the chemical
verbiage and symbols. However, it might be worth a look, either to see
if what you're trying to do might require a more complicated process
than you want to replicate, or to see if you can pick up some
information on how you might proceed more successfully. The filtering
idea from pinkfreud makes sense. Initially, I was wondering if putting
the extract through some kind of paper filter might help, but again, I
have no concrete evidence to support that idea. Here's the pdf file of
the article. If I find anything else more helpful, I will post it here
as well.

http://www.scielo.br/pdf/bjce/v21n3/a09v21n3.pdf

A couple more webpages that might help:

Another recipe for stevia extract that combines your idea about vodka
with my thought about coffee filters! This one uses fresh herbs as
well.

STEVIA EXTRACT
To make a liquid extract, combine 1 cup vodka  with 3/4 cup macerated
fresh stevia leaves in a jar with a lid.  Shake everyday for two
weeks, then filter through a coffee filter.  Label store in cupboard. 
Add a drop to beverages.

http://www.blossomfarm.com/herb_recipes.htm

Here's another page of hints on how to make tinctures. The focus is on
medicinal tinctures, but you may find transferable tips here to try in
your process.

http://members.cox.net/contentmentacres/howtotinctures.htm

Good luck!!

thank you Pink and thursdaylast ---

(sure wish GA would fix their email notification service . . . )

these are all good ideas, and now the proof will be in experimenting
with it sometime this summer.  The glycerine based extract (on
'contentment acres' website) sounds like a good one to try too. The
label on the SteviaClear bottle says 'stevia, purified water and
grapefruit seed extract'.  The grapefruit seed extract is probably to
keep bacteria growth down, but it's interesting that it's
non-alcoholic and not even a glycerine base.

thanks again!


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