Rotate the Flushes

What is a flush?

When a colonized bag makes a whole batch of mushrooms at once, growers call that batch a flush. After you harvest a flush, the bag is not finished. With a little rest and care, the same block can grow another batch — a second flush, and sometimes a third.

Getting more than one flush from a single bag is one of the best parts of a mini farm. It means more mushrooms from the same block, for free. Learning to rotate the flushes — resting each spent bag and coaxing it to fruit again — is the heart of running the shelf.

How many flushes to expect

Here is what growers and studies generally find with oyster bags:

• Most home bags give two or three flushes before the block is spent.

• The first flush is the biggest. Studies of oyster bags found more than half of the total harvest comes in the first flush or two.

• Each later flush is usually smaller than the one before, because the mycelium has used up much of the food in the block.

So do not be disappointed when flush two is smaller than flush one. That is completely normal and expected. A strong first flush is the one to aim for.

Resting and reviving a bag

After you pick the first flush, the block needs a short rest and often a drink of water to refill what it lost. Here is the gentle routine:

1. Let the block rest a day or two after harvesting.

2. If it feels light and dry, it may need rehydrating. Many growers soak the block in cool water for a short time — often around 12 hours — to refill its moisture.

3. An adult handles the soaking. Lifting a heavy wet block and managing tubs of water is an adult job. You plan the timing, watch, and take notes.

4. Do not over-soak. Leaving a block in water too long lets bacteria move in and can spoil it, so timing matters.

5. Keep misting as before. Pins for the next flush often appear a few days to a couple of weeks after the block is watered again.

One safety note: never seal up or peel all the plastic off the bag between flushes. The mycelium breathes through the slits, and the film keeps the surface from drying out. Leave the bag as the kit designed it.

Rotating the whole shelf

Now put it together with your staggered plan. At any moment your shelf might have:

• a new bag colonizing,

• one bag on its big first flush,

• an older bag resting and reviving for its second flush.

Each bag is at a different point in its own cycle, so fresh mushrooms keep coming. To rotate well, you must know which bag is on which flush — and that is impossible to remember in your head across many bags. The answer is to write it down. In the next lesson, you will build a yield log to track exactly that.