Anything in your Grow Kit that is not coffee grounds should be white or beige. A yellow or red-ish fluid might appear, which is normal. If you on the other hand observe green mould (rarely also orange) it is a clear sign of contamination.
Contamination can occur if the Kit has not been properly cleaned before using it, for example, if you've used dirty tools to add the coffee grounds, if the substrate is too dry, or if mould spores in the air for some reason dominate the white oyster mushroom spores.
If you only see a small patch of green mould in your Grow Kit, you can - in most cases - simply remove the attacked area with a clean spoon. Keep a daily eye on the development, and remove the mould if it returns. Make sure the substrate is moist at all times.
If the contamination has spread to a larger area of the Kit, you will have to discard all of the substrate. Then, clean the bucket thoroughly and wipe it with household spirits. You can then restart the Kit by buying a new bag of mycelium in our shop.
Also, if the substrate is contaminated with mould or is too dry, you can buy a fresh bag of mycelium in our shop at 60 DKK/bag, and restart the process - after you have cleaned your bucket.