Harvesting mushrooms is a delicate process that requires care to ensure you do not damage the mycelium and substrate, which would impact further flushes. Here are the detailed instructions on how to harvest mushrooms:

Materials Needed:

- Mature mushrooms ready for harvest
- Sterile gloves
- Small sharp knife (optional)
- Paper bag or wax paper for storing harvested mushrooms

Instructions:

1. Prepare for Harvest: Clean your hands and put on a pair of sterile gloves. Ensure your workspace is clean to minimize the risk of introducing contaminants to the grow area.

2. Identify Mature Mushrooms: A mushroom is generally ready to harvest when the cap has fully expanded and just before or right after the veil underneath the cap starts to tear. The veil is a thin layer of tissue that connects the stem and the cap. This is generally the point when the mushroom is most potent and before it starts to release spores, which can create a mess and potentially cause breathing issues for some people.

3. Harvesting the Mushroom: To harvest the mushroom, you can either twist and pull it off at the base or cut it off at the base with a sharp knife. The choice is largely a matter of personal preference.

   - If you choose to twist and pull, grasp the mushroom at the base of the stem and gently twist it while pulling upwards. This method is simple and does not require any tools, but you must be careful not to disturb or damage the surrounding mycelium.

   - If you choose to use a knife, simply cut the mushroom off at the base of the stem. This method can be a bit cleaner and less disruptive to the substrate, but it does leave a small stub of the mushroom behind which can potentially rot and introduce contamination.

4. Storing the Harvested Mushrooms: Once harvested, place the mushrooms on a clean surface, like wax paper. If you're not planning to consume or process them immediately, store them in a paper bag in the refrigerator. Mushrooms should not be stored in airtight containers or plastic bags because they can build up moisture and rapidly degrade.

5. Clean Up: Once you've finished harvesting, clean up your workspace. If you used a knife, make sure to clean it thoroughly.

6. Prepare for Next Flush: After the first flush has been harvested, there may be more flushes to come. You'll need to rehydrate the substrate to prepare for the next flush. This can be done by soaking the substrate in water for a few hours, then draining and returning it to the fruiting conditions.

Remember, the timing of the harvest is crucial for getting the most out of your mushrooms. Also, the way you handle and store your mushrooms after harvesting can significantly impact their potency and shelf-life. Always handle your mushrooms with clean hands and tools, and store them properly for the best results.