These are the tools you will need to separate epiphyllum seeds from their fruit. They consist of a couple of bowls, a glass jar with lid, a sharp knife, a spoon, a pen or marker for labeling, a screen-type strainer, a cookie sheet, and a silicone non-stick baking mat or a sheet of wax or parchment paper. You may also want to have on hand a roll of paper towels, paper or tape for labeling, a pair of tweezers and some small ziplock plastic bags.
Using the sharp knife cut the fruit in half lengthwise. I like to do this on a slight diagonal. This avoids having to cut through the tough bits at either end of the fruit. Watch your fingers!
The halved fruit displayed cut side up to show the seeds.
Scoop the pulp and seeds from the fruit using the spoon.
The scooped out pulp and seeds in a bowl. Note the empty fruit skin in my left hand. If any seeds remain clinging to the skin, you can scrape them out with the edge of the spoon.
Mash the fruit as completely as possible with your hands. You’ll notice the sticky sliminess of the pulp as you squish it between your fingers. Yuck! This stickiness is why you want to try to separate the pulp from the seeds as completely as possible. If a lot of pulp remains with the seeds later when you dry them, it will glue them together in clumps, making it difficult to sow them evenly when it is time to plant.
The hand mashed fruit in a bowl. At this stage, some of the seeds have been separated from the pulp, and some seeds are still adhering to pieces of pulp.
Place the strainer in the other bowl. Spoon the mashed fruit into the strainer a little bit at a time and push it through the mesh with your fingers. Some of the seeds will go through the screen and some of them will not. When you have strained all of the mashed fruit through the screen, scrape the whole mess from both sides of the screen into the bowl with the edge of the spoon. Any seedless pulp left on the screen can be discarded. This step separates even more of the seeds from the pulp.
This is the fruit in the bowl after straining.
Pour the strained fruit into the jar. If any material sticks to the bowl, scrape it into the jar using the spoon.
Fill the jar with water leaving an inch or so of headroom. Tap water will work just as well as bottled water.
Filled jar with lid secured. Tighten the lid enough to prevent leakage.
With the lid secured, shake the jar vigorously, agitating the seeds and pulp. Let the jar stand for 24 to 36 hours. You can agitate it again a couple of times during this period.
This is the jar of pulp and seeds with some back lighting to show the separation of layers after a period of settling. The non-viable seeds have floated to the top. The good seeds have settled to the bottom along with some of the pulp. The longer the jar sits, the more pulp will float up into the middle levels of the jar.
After the settling period, slowly and carefully decant the floating non-viable seeds and floating pulp from the jar. Try not to agitate the jar too much.
Continue slowly decanting until you don’t think you can get any more material out of the jar without spilling the good seeds. At this point, if you think it is necessary, you can add more water to the jar, allow the contents to settle for a few minutes and then repeat the decanting process. Decanted non-viable seeds and pulp can be discarded.
Once you have decanted all you can, you may want to spoon out any remaining floating (non-viable) seeds or pulp. Once that is done, what you should be left with are good seeds, very little remaining pulp and very little remaining water.