AsNoriuanswered grow question 1mo ago Roots will rot, but right humidity, few bacterias, black bag, no direct light and in 3-6 month you can reuse it, BUT :
How many and what nutes are inside, has your ph been stable and so on ...
About pest problem i dont speak even, if you had, youll have more, if you kept bag in wrong conditions - you can catch more ...
I dont do my own soil mixes even, i found its cheaper and more reliable to buy branded one and enrich it ...