Add your vinegar to your pot.
 

Slowly add your baking soda, one tablespoon at a time. The two substances will react as you add the powder, let it fizzle out before you add more. Then stir until all of the powder is dissolved and your liquid is clear.
 

On the stove, over a very low heat, let your solution sit for about an hour. Make sure you keep an eye on your pot as it’s very easy to overheat. If the heat is too high, the liquid will turn yellowish-brown; this will still work so don’t worry if this happens.

As you reduce the liquid, you’ll see crystals forming on the side of your pot. This step is done when you see small white crystals forming on top of your liquid. Make sure to turn off the stove.
 

Pour the liquid into a heatproof dish. Cover with aluminum foil and put it in the refrigerator. This is to remove excess heat and can take anywhere between 1-2 hours. Be very careful with your liquid; any bump can start the reaction before you’re ready to watch it.
 

Back at your stovetop, use a skewer to scrape the white crystals from the side and bottom of your pot. Keep these, they are your Seed Crystals to begin your reaction.
 

Add a Seed Crystal to your Sodium Acetate Solution to watch the liquid change to a solid. Or pour the liquid onto some Seed Crystals to form a tower that looks like it’s made of ice!
 

You can put your crystals into a heatproof dish and into a pot of gently boiling water to turn the crystals back into a liquid so you can repeat your experiment or make changes and try something new.