How to Save Spaghetti Squash Seeds
To get your seeds ready for storage, start by cutting open a ripe spaghetti squash and scooping out the insides. Place the substance in water and let it sit until the mixture separates, leaving dead seeds and pulp on top and good seeds on bottom. Pour out everything except the good seeds, then rinse them off multiple times. To dry the seeds, lay them out on a tray or sheet of paper and set them in a dark place for about 3 days.
Get a ripe spaghetti squash. For the best seeds possible, pick a spaghetti squash that is firm and fairly heavy. When fully ripe, the squash should have a rich, yellow color; if it's green, it's not ready. If possible, avoid harvesting seeds from squash that are cracked or soft, since they may have been exposed to bacteria. Cut open the squash. Open up the squash using a sharp, clean kitchen knife. Then, separate your squash into 2 halves, revealing a soft, stringy interior. Remove the seeds. With a spoon, scoop out every bit of the stringy substance from inside the squash, then set it aside for later use. The stringy substance is made up of the fruit's seeds and the pulp connecting them together. When you're finished, the inside of the spaghetti squash should look completely smooth and uniform. If you plan on cooking your squash, make sure to harvest the seeds before doing so. Place your seeds in a bucket of water. Grab a bucket and fill it with a large amount of cool water. Set it in an area where it will not be disturbed, then drop your seed and pulp mixture inside. This will give your seeds a chance to both get clean and germinate. Let everything ferment until the mixture separates. In addition to simply cleaning everything up, the water will help you determine which seeds are worth keeping. Good seeds, ones that are still alive and rich with nutrients, will sink to the bottom of the water. Dead seeds, along with pulp, will rise to the top. Let the seeds sit until they are fully separated, which normally takes about 1 day. Discard the seeds and pulp on the surface of the water. Once they've had enough time to sit, carefully pour out the water so that the dead seeds and pulp escape while the healthy seeds remain in the bottom of the bucket. Rinse the good seeds off with cool water. To make sure the healthy seeds are as clean as possible, fill the bucket up with new, fresh water. Let the seeds soak for a few seconds, then pour the water out. Repeat this 3 or 4 times. Rinsing the seeds thoroughly will remove dirt and grime, preventing them from sticking to the drying sheet. Place your seeds on a drying sheet. Once you've rinsed off your seeds, move them to a glass tray, a ceramic plate, or a sheet of flat newspaper. Spread the seeds out so that they each have ample room and are not touching the other seeds. Let your seeds sit in a dark place until they are completely dry. Put your seed tray in a dark area, like a basement or closet, and let them sit until fully dry. If you do not have access to a dark area large enough for your seeds, cover them with multiple sheets of newspaper. Your seeds should be completely dry after 2 or 3 days. Check on your seeds twice a day. While checking your seeds, look out for any that may be rotting or decaying and remove them from the tray. Make sure to clean off any pooling water and, if necessary, remove wet and soiled newspaper. Remove excess pulp if necessary. Once your seeds are completely dry, you may find that there is still a small amount of pulp left on them. To get rid of it, simply peel they excess pulp off the seeds and dispose of it. Wrap your seeds in paper. To keep your seeds contained, place them inside a small paper envelope or wrap them in a dry paper towel. This is especially important if you plan to store different types of seeds in the same container. After placing your seeds inside, examine the paper to see if any moisture appeared. If some did, give the seeds another day to dry, that way you don't encourage mold or mildew growth. Seal your seeds inside a jar. Get a solid glass container, like a mason jar, and wash it with antibacterial soap. Rinse out all the soap and dry the jar. Once the jar is completely dry, place your paper packet of seeds inside. Cover the container with a lid and make sure to close it tight, thereby keeping as much bacteria out as possible. Label the jar. To avoid mixing the seeds up with other strains, and so you remember when the seeds were cultivated, label the jar in clear, legible handwriting. Include the seed type, when you harvested the seeds, and when you plan to place the seeds in storage. Move your seeds to a refrigerator until you're ready to plant them. To keep your seeds happy and healthy, store them in a refrigerator or similarly cool place. Seeds need consistent temperatures, so choose a spot where you won't need to move them often. Do not store your seeds for more than 6 years. While in storage, spaghetti squash seeds can last anywhere from 3 to 6 years, though they are best when used as soon as possible. To test if your squash seeds are still good, check for rot or mildew. If you don't see anything, place the seeds in water; if they float, they've gone bad! 
Get a ripe spaghetti squash. Cut open the squash. Remove the seeds. Place your seeds in a bucket of water. Let everything ferment until the mixture separates. Discard the seeds and pulp on the surface of the water. Rinse the good seeds off with cool water. Place your seeds on a drying sheet. Let your seeds sit in a dark place until they are completely dry. Check on your seeds twice a day. Remove excess pulp if necessary. Wrap your seeds in paper. Seal your seeds inside a jar. Label the jar. Move your seeds to a refrigerator until you're ready to plant them. Do not store your seeds for more than 6 years. 