Hello everyone, this is my first post! Thanks for all the great info. This thread is especially good and the best seed sowing guide I could find on the internet. I have very good germination from my first batch of seed!
I'm using a 1:1:1 mix, as above, and bagging them with a hole in the bag. While the seedlings are still young, I've gotten good results so far. I'm new to the Nepenthes hobby, and although I'm not formally a microbiologist, I know a thing or two about microbes.
Microbiologists know that sterilization and pasteurization are totally different things. Actual sterilization requires temps above 250F. NOBODY is sterilizing their media - this requires an autoclave or a pressure cooker or something. Pasteurization, with temps ranging from 140F to 170F (100 degrees F cooler than sterilizing!) is a maneuver which yields a microbiologically stable environment by killing most active organisms, and sparing the dormant ones. While killing multicellular organisms like nematodes and insect eggs and also colonies of active fungi and bacteria, it leaves most endospores and some favorable bacteria intact (actinomycetes actually thrives in low pasteurization temperatures). This levels the playing field in the competition for nutrients, but still allows plenty of biodiversity. This way, they all keep each other from growing unchecked across a nutrient source (the soil). Believe it or not, trichoderma, rightly mentioned above as a great soil stabilizer, is also the same green mold you see in failed pots (or possibly penicillin). The difference is that the overcooked media favors the mold so much that it gains enough nutrition to grow "vegetatively" and sporify. - potentially deadly for a seed caught in the cross-fire. We want a slow, lazy war among these microorganisms, and not a massive, single-front offensive.
The only effective way I'm aware of really pasteurizing soil correctly at home is in an analog turkey roaster set to low and monitored with a meat thermometer (I go for 145F). The media is then hydrated to field capacity, so approximately that's when no water comes out when squeezed, and only 1 - 3 drops come when squeezed "hard." The moistened media is put in a moist pillowcase along with a little water for an hour or two. I haven't tried this on Nepenthes seeds, but on rather more sensitive applications here on my mushroom farm. Its the industry standard for microbial stability.
In my opinion, the preference would be as follows:
1. pasteurized (the best by far)
Microwaving until "the media gets hot, but not hot enough to burn you" works quite well. In my new micro thats 44 seconds on high for a single 4 - inch round pot of moist media. I've gotten great germination and nearly zero mold. In fact, I did an accidental side by side comparison with some media heated to boiling, and some to "just hot" as above. The microed pots have healthy seedlings of about 40% germination which I think is great. The three I overcooked just turned green and I have maybe three seedlings per pot (quite poor).
Here's a link to an article I'm finding useful regarding raising out the young seedlings: