Mix and mold
As you keep adding liquid to the dry ingredients, you’ll see small clumps forming. Continue stirring and misting until you’ve used 2/3 of the liquid in your bottle.
Now try molding it!
Get a small amount in your hand to make a fist. If it clumps well — it doesn’t need to be completely moist or wet! — it’s ready to press into the mold.
TIP: Wait a few minutes before you add additional water to your mix.
Keep in mind the ideal mix should be slightly dry, rather than a sticky paste.
The moisture will activate the citric acid and start a reaction between the citric acid and the baking soda.
CAUTION: If you add too much liquid, your mix will expand and start the fizzing now, instead of later.