Some times I've had problems with mold, probably spores hidden in the seed (The shell covering Astrophytum seeds, for example, is an excelent place for such thing s to hide).
When your mother makes jam, juice or similar, she will typically add a preservative in it. These preservatives contains in many (or all?) cases Sodium benzoate, an effective fungi-killer. The most known brand around here (Scandinavia) is called "Atamon", but look around in your local supermarket for food-preservatives and take a look at the product's table of contents.
I use aprox. 1 teaspoon pr litre (.25 gallon). I let the seedlings float around in it for a few hours. After that I soak the soil in the solution before I put the seeds in it. It does not affect growth in any way.
Sterilizing the soil is usually a waste of time, I never do that anymore.
Hope this is useful
). You may never know what kind of "metabolites" are generated which may be far more toxic and carcinogenic than the original product ever was ..
They have it a eBay: