Homemade ketchup is a healthy, delicious alternative to store-bought versions. If you want to start cooking your own condiments, here is an easy guide to making your own ketchup:

Choose the right tomatoes
The best ketchup is made with fresh tomatoes. You will need at least 10 pounds of tomatoes. This may sound like a lot, but removing the skin and seeds will shrink your produce dramatically. Choose farm-fresh tomatoes and avoid any that are soft and bruised. Tomatoes come in a number of varieties, but while most large tomatoes will work just fine, some are better suited for making ketchup than others. Roma, or paste tomatoes, are particularly apt, thanks to their meaty flesh. Beefsteak tomatoes are also meaty enough to make great ketchup. If you want to make unique ketchup, try experimenting with orange or green tomatoes.

Remove the skins, seeds and excess water
Tomato skins will create unpleasant textures in your ketchup, so you want to remove the skins through a process called blanching. To blanch your tomatoes, submerge them into boiling water for a little less than a minute. Use a slotted spoon to take the tomatoes out of the hot pot, then immediately plunge them into a bowl of icy cold water. This process will allow you to pull the skin right off of the tomato.

Next you will want to remove the seeds. Cut the tomato in half, give them a little squeeze -- then spoon out the seeds and excess water. Drain the tomatoes in a colander or cheese cloth to remove the last of the water -- which is also drinkable tomato juice.

Season and cook
Seasonings add extra flavor to your ketchup and distinguish it from plain, old tomato paste. Simmer the tomatoes with garlic, onions, pepper, salt, sugar and vinegar -- either apple cider or red wine. You can also experiment and include more flavors such as cayenne pepper or fennel. Simmer the mixture until it thickens quite a bit. This will take several hours, so prepare ahead of time.

Store the ketchup
To achieve the ideal ketchup consistency, puree the ketchup in a blender until it reaches your liking. Use a mesh strainer to remove any leftover seeds or skin. Transfer your homemade ketchup into a clean jar with a lid or an old ketchup bottle. You can usually store this in the refrigerator for about a  week.

If you want to store ketchup for longer, you can use traditional canning methods. Fill clean glass jars with ketchup, place the lid on top and tighten the ring to seal it. Inside a canner or large pot of boiling water, submerge the sealed jars, and make sure to use enough water to cover at least an inch above the lids. Use jar lifting tongs to keep your hands at a safe distance from the hot water. Boil the jars in the pot for at least a half hour to seal and sanitize. Once you have finished, let the jars cool on a counter-top overnight. Press the seals to make sure that no air can enter the jars; if it pops, you may have to seal the ketchup jar again.