The first DMT that I tried, was described as "non-chemical extraction", although no details were provided.

It gave me the same visuals that I'm having with my current (different) batches, but it also gave me some horrible shivering, shakiness, hot-cold, etc. It was extremely unpleasant, and definitely not a way in which you would like to breakthrough.
With the substances that I've had after that one, none of that happened.

Unfortunately I don't have any more of the substance to send to testing services, but has anyone experienced something similar? Any idea what was that about?

What did it look like? Was it white crystals?

I usually experience shivering and shaking with Ayahuasca and consider it a desirable effect, one that makes it a good medicine.

Well that non chemical extraciton was a lie. Everything is made up of chemicals.
Prolly just the same as other dmt but the setting made the difference.

Haven't tried aya, but regardless, that shaking and shivering cannot by desirable, not even normal or minor side effect. I'm someone that always puts up really good with side effects, comedowns, etc, but this was a clearly indication that something was off.

Looked yellowish, just like the batch that I have now and doesn't have even a hint of that side effect, even with bigger doses.

Totally agree with the first part, "everything is made up of chemicals".
You can see in my Introduction Essay that I strongly disagree with the "natural/synthetic" dichotomy.

Also, totally disagree with "the setting made the difference". The setting could affect the trip, mentally, but not that level of shivering, that's clearly something else. Different settings produced the same shivering, and different batch with same settings produced no side effects.