Some vegetable seeds, like tomato and pepper seeds, can host bacteria. This bacteria can spread quickly and damage the plant once the seed germinates. Companies typically treat their seeds with sodium hypochlorite, which sterilizes the surface of the seed. However, any bacteria within the seed is left undamaged. A hot water soak can penetrate the seed and kill the bacteria, but there are a few risks; if the seed crop was grown under stressful environmental conditions, soaking the seed in hot water may cause poor germination.
Bring a water bath up to between 122 and 125 degrees Fahrenheit, depending on the type of seed you are treating. Heat the water to 122 degrees F for pepper, cabbage, cauliflower, broccoli and Brussels sprouts seeds. Heat the water to 125 degrees F for tomato seeds.
Wrap 50 to 100 seeds in cheesecloth along with a metal bolt and add the seeds into the water bath.
Stir the water and monitor the temperature constantly throughout the entire bath. Bathe pepper, cabbage and Brussels sprouts seeds for 25 minutes. Bathe cauliflower and broccoli seeds for 20 minutes. Bathe tomato seeds for 20 minutes.
Cool the seeds under tap water. Spread them out on paper towels and allow them to air dry at 70 to 75 degrees Fahrenheit.
Test the germination of the seeds by putting them in moist paper towels. Prepare another sample of untreated vegetable seeds and compare the germination rates between the two.
Bathe the rest of your seeds in the hot water bath if germination rate is not substantially reduced compared to the untreated sample.