This is what you need:
- Large glass jar and lid (I use a big old applesauce jar) or 2 mason jars
- wire whisk, spoon
- saucepan (2+ quart)
- soy milk (refrigerated or boxed*); vanilla is yummy for yogurt!
- plain gelatin (for thickening)
- candy thermometer
- To get started, boil some water, then stick the whisk and spoon in the jar and pour the water in to sterilize, don't forget the lid. (I put it right into the cooler in case I spill some water)
- If you use refrigerated soy milk, you will heat 4 c. soy milk in your saucepan to 180° to kill off competing bacteria. Then remove and cool to 110°-115°. (set the jar in a sink of lukewarm water and wait about 15-20 min.)
- For boxed milk, you can use it straight from the box (it is sterile); for best results, warm slightly by setting the box in warm water in your sink or cooler.
- When your milk is down to 115°, add about 1/2 container of plain soy yogurt with live and active cultures and 1 packet unflavored gelatin; whisk together.
- Cover jar with lid.
- Fill your cooler with warm water, about 110°; gently place in your jar and close it up. The water should be as high as the yogurt, it does not need to cover the top of the jar (It needs to be kept at 90°-110°, and the cooler should maintain that temperature).
- DO NOT DISTURB for at least 6 hours. I usually wait 8 hours. I have never been able to get soy yogurt to thicken as much as dairy yogurt (but you will see a thicker consistency). I end up with a nice drinkable yogurt; it works especially great in smoothies for my dairy-allergic son. If it is not done, you can add warm water to bring the temperature in the cooler back up to 100°-110°.
If, for some reason, your yogurt fails, you can still use the end product in baking (biscuits, muffins, pancakes, bread, cake etc.)
*refrigerated soy milk such as Silk will result in a creamier consistency for your yogurt.
I am also looking into using acidophilus for a starter rather than commercial yogurt, though apparently some powdered acidophilus has casein in it! So watch out if you have a dairy allergy!
for photos and complete details, see my Dairy Yogurt in your Cooler post.