We evaluated Stevia as a Sweetener; Here is What we Learned

In recent months, we have had several customers ask us to use Stevia as a sweetener.

As you know, we take your requests seriously, and we take quality very seriously. So, we looked into the Stevia manufacturing process. Like you, we expected to hear how natural and pure Stevia is - much of the marketing involved the colors green and white.

Here's what we found. Please tell us what you think.
We are told that there are two major producers. One of the two, or maybe both, ship the "raw material" to China for processing.
A source shared with us a flowchart for the production process for one of the two companies. It mentions the use of alcohol to extract the Stevia. But the chart also shows the use of:
a. "Solvent 1"
b. "Solvent 2"

We haven't yet found a source that will share what those solvents are. How bad could they be? We just don't know.

Question: What kinds of chemicals are "solvents"?
Answer: There are many different kinds. One example: in earlier times, coffee used to be decaffeinated using benzene (source: Scientific American). Benzene is considered quite toxic and a carcinogen (CDC.gov).

We also heard from one Chinese manufacturer who would not share anything about how the product is made.

So we are concerned about these things:
Why all the secrecy around how it is made?

Why ship it to China?

It is because it is easier to conceal unsavory manufacturing practices over there? (There is much less regulation in China and far fewer consumer protections.)

What are Solvent 1 and Solvent 2? Why doesn't the seller name the solvents?

So if we used Stevia in our product, we probably wouldn't able to tell you for sure what chemicals are in the product, or how it is made. How can we go forward without knowing whether there is something toxic or carcinogenic in the product? That would betray your trust in us.