Step 1: Ingredients
Pictures are a triple recipe..not much acetic acid in vinegar
2 tablespoons baking soda
900 ml distilled white vinegar 5% acetic acid
stainless steel or glass boiling vessel
funnel for filtering
I used 3 times the amount and boiled on the stove in large pan until small enough left to fit into my beaker (about 500 ml) boil to 250 ml if tripling recipe
put baking soda in pan first! this does not froth over as much
add vinegar to it slowly until all is added, slowly to avoid frothing over.
you will boil most of the vinegar away
Step 2: Making It (picture Is of Next Step)
as its boiling if solution goes cloudy add vinegar to clear it
If, or when, you see flakes coming out of solution this is unreacted reactant, add more vinegar (it wants more acetate ion)
put coffee filter into a funnel.
solution should eventually turn a darker brown from tan when its close to enough vinegar added,
Start testing a little before end volume is reached
I use a small glass bottle to test for end point.
Crystals will be small clear slivers not tan flakes,
remove small amount of solution (1tsp), put into small bottle with a toothpick, let it cool if it makes small amount of little crystals you are close. I use a flashlight to look through test material.
If not keep boiling down.
Step 3: Endpoint and Filtering
when you see many crystals forming, its at the end, save test crystals on small plate
pour solution through coffee filter into clean glass container.
cover to keep out dust.
place container in bowl of cool water to come down to room temp.
it should stay clear, if it goes goey brown not enough vinegar boil again. Also keep out dirt and contaminants.
when its room temp, drop in crytal from test material and watch it make beautiful crystals.
Most of solution should turn to crystals
Pour off excess liquid onto a coffee filter on a plate much of it will turn to crystals as it dries.
Step 4: Refining
Hold bag of crystals in boiling water, dont let water in
when re-liquified allow to cool to room temp, drop in test crystal
let harden and cool, pour of excess save excess as before,
you can repeat this step 4-5 times or as needed until its one solid crystal when it crystalizes. The liquid will be mostly clear at this point ( no fancy filtering ever needed )
I did this experiment three times this weekend, triple recipe each time, it worked great every time. all other attempts previously I had not added enough vinegar.
boil down, add vineggar to clear,boil add, boil add you get the picture:) test test test theres the crystals done. If you get small yield of crystals it needed boiled down a little further.
Hope this helps Enjoy