if someone made kratom extract usually by boiling it in vinegar and water, but didn't have vinegar, but had food grade glacial acetic acid and made vinegar by mixing 1000mg with 50ml of acetic acid(diluted at five percent i beleive but could be wrong) and the boiled it all the down to being dry would this be safe to consume?

I'd like to help here as I did a plain water and lemon juice extraction on about 300 grams of super fine ground Red-Bornio leaf on Sunday evening.
I say 'I'd like to help' because unfortunately our cleaner who comes on a monday to tidy our house found the concentrated tea in a long clear glass oven dish in the kitchen ( where I'd hoped to oven dry the final concentrate to a resin) she thought it was left over chicken fat and gravy and chucked the lot.

I'd spent about 5 hours boiling, filtering, adding water, filtering again, boiling, filtering, adding water etc etc.

Sadly all my hard work literally went down the drain

One thing I can say is that I have no idea how people on some forums claim they can make an extract in under an hour Took me absolutely ages and I still hand't got that close to a resin or hard material by the time my otherwise lovely housekeeper dumped the lot.

I've heard whispers on the wind of alcohol extractions -- soaking the plant material in IPA then filtering and evapping the remaining alcohol for a pure concentrate. Sounds simpler and wouldn't make the house stink of shit.

Awooga

They could have also just not been too thorough in there extractions. It take me hours and hours to finish an extraction too. I do a fair number of washes on plant matter when I'm extracting. I like to be sure i get everything.
I would do alcohol or other extractions, but i like the water ones. The product seems pretty comparable to plain leaf in effect. I guess it's the cheapest. Although the texture of isopropanol extracts is kinda cool.
This time i able to boil it down the water extract to a nice hard extract, which turns into powder nicely. I wanna know if it's safe to have used food grade acetic acid in place of store bought vinegar as my acid.

Is there any reason you can't get some vinegar? Here in the states it's about $2 for a gallon at pretty much any store. Just a thought.

Of course the chemistry can be interesting, but if you're concerned for your health, I'd say it's not worth it. You could even buy a small bottle for around a dollar.