good question. the higher spawn ratio used the faster colonization will be leading to less chance of contamination and also using more spawn can give higher yields. foaf thinks it does seal out and ward off contams but then the top layer isn't in the best condition for pins unless bulk is cased. foaf thinks the layer of spawn on top is a good thing IF you case your bulks, otw it is best to do the layer of unmixed on top or just mix all the spawn and substrate together. When foaf does unmixed on top, the mycelium tends to grow more rhizomorphic and looks healthier than topspawning. If the mycelium grows uneven upwards through that top layer of substrate, you can always save spawn to sprinkle on top in spots (like patching a casing)to even out the growth and get top of the substrate to 100 percent colonization quicker than just waiting.
