A shiitake mushroom log once impregnated takes from 6 months to bear fruit.
It can take longer if conditions are not meet with, moisture and heat.
Usually you drill then impregnated the hole and seal with wax. This whole procedure should be done as sterile as possible.
Keep your log in a shaded area with adequate air circulation. If a black or green mould appear, wipe mould with a diluted bleached rage. Mist your log every couple of days to keep log moist but not wet.
I have not tried this product from here, but have had cultured packs which are a ready to go mushroom farm.
my experiences are with The Shiitake(Lentinula edodes), The oyster mushroom( Pleurotus ostreatus), The Enokidake (Flammulina velutipes), maitake (Grifola frondosa). Hope this help you, and future purchasing people.