When you get your hands on a really delicious apple, you may be tempted to plant its seeds and grow your own supply. But before you go through the trouble, you should know that most of the apples sold in supermarket are hybrids grown from cloned or 'grafted' trees. Commercial growers don't plant apple seeds because they do not grow true to type. And its quite likely that the grocery store apple seed you just bought will grow a tree whose fruit has little in common with the apple you just finished eating.
Roll all of the seeds from your apple in a damp paper towel.
Place the paper towel on a paper plate and place it in your refrigerator until the seeds split open and produce a single sprout (one or two weeks). Check on your seeds daily after one week has passed. They should germinate soon after that time. Once the seeds have sprouts that are just a bit longer than the seed itself, take them out of the refrigerator. Discard the seeds that do not germinate.
Plant each germinated apple seeds roughly 1/4 inch deep in a small pot filled with potting soil.
Water the pot's soil until water drips out of the drainage holes in the bottom of the pot. Continue to keep the soil moist, watering whenever the soil feels dry to the touch (every couple of days).
Keep the seedlings in a warm spot that receives indirect sunlight until they break through the soil's surface. Once they reach a few inches in height, move the seedlings into direct sunlight on a sunny windowsill.
Transplant the strongest apple seedling(s) out of doors the following spring. Compost or throw away small, spindly seedlings.