Wash a quart-size canning jar and canning ring in soapy water. Rinse clean and allow it to dry.
Cut a piece of stainless steel window screen material to fit inside the canning lid ring. Use the ring as a guide to ensure the screen material is cut to the proper size.
Place 1 to 2 tbsp. of sprouting seeds inside the jar. Fill the jar with water.
Set the screen on top the jar opening. Screw on the ring, securing the screen to the jar.
Place the jar in a warm, dark place, such as inside a kitchen cabinet. Soak the seeds in the water for 24 hours.
Drain the water from the jar, pouring it through the screen. Pour fresh water through the screen, rinse the seeds, then pour out the water. Repeat two to three times daily.
Rinse a final time once the sprouts reach the desired size, usually between 1/2 and 1 inch long, depending on the seed variety. Sprouts take between three and five days before they are ready to eat.