Before the creation of picture-perfect hybrid tomatoes that could withstand the rigors of mass production and transportation, early gardeners grew tomatoes from superior seeds passed from one generation to the next. Unlike the streamlined, barely ripened orbs found in the grocery, heirloom tomatoes come in a plethora of shapes, sizes, colors and weights. Heirloom tomato seeds, originating from all over the world, help to sustain precious food resources as they are harvested, saved and traded by family and community members.
Choose a ripe heirloom tomato specimen that is free of blemishes or cracks from a plant that is free of disease.
Label containers or lids with the type of tomato and date. Label several coffee filters with this information as well.
Cut the tomato in half and squeeze seeds, pulp and juice into clean, sterile containers.
Cover containers loosely with lids and set them in a warm location, out of direct sunlight. Do not seal containers or they will explode from the building gasses caused by fermentation.
Allow seeds to sit and ferment for one to three days, stirring occasionally to release any viable seeds from the scum that forms on top of the tomato material.
Harvest viable seeds by gently pouring off the top layer of scum. Add water, stir to remove any remaining residue, and repeat this process until the seeds are free of gelatinous coating and other materials.
Lay coffee filters over a screen and spread cleaned heirloom seeds over the filters to dry. Place the screen in a warm, dry location and allow seeds to dry thoroughly for up to seven days.
Place dried seeds in glass jars with lids and keep in a cool, dry location for storage. Label jars with tomato type and date of harvest.