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You harvest mushroom blocks by twisting or cutting the mature mushrooms at the base of the stem, and timing is everything for the best yield.
If you’ve ever grown your own mushrooms, you know that harvesting mushroom blocks is a rewarding moment, but it can feel a little tricky if you’re unsure when to pick.
The good news is that learning how to harvest mushroom blocks isn’t complicated, and once you get the hang of it, you’ll be pulling fresh mushrooms like a pro.
In this post, we’ll break down exactly when and how to harvest mushroom blocks, what tools you need, and how to get multiple flushes from the same block.
Let’s dive in and make sure your mushroom harvest is as bountiful as possible.
Why Harvesting Mushroom Blocks at the Right Time Matters
Harvesting mushroom blocks at the right time is the single most important factor in getting great flavor and texture.
If you wait too long, the mushrooms will drop their spores, which can make a mess and cause the caps to turn dark and mushy.
If you pick too early, you might sacrifice size and weight, leaving flavor on the table.
Here’s what to look for to know exactly when to harvest mushroom blocks.
1. Watch the Cap Shape and Veil
The classic sign that mushrooms are ready to harvest is when the cap has fully opened but the veil underneath is still intact.
For varieties like oyster and shiitake, you want the cap edges to be smooth and slightly curled under.
If the veil has already torn and the gills are fully exposed, you’ve waited a bit too long.
Checking your blocks daily is key because mushrooms can go from perfect to overripe in just a few hours.
2. Check the Size and Firmness
Most mushrooms should be harvested when they reach about 2 to 4 inches in diameter, depending on the variety.
A gentle squeeze should feel firm yet slightly springy, not soft or spongy.
If they feel too soft, they’ve started to degrade, so don’t delay harvesting mushroom blocks once you notice that texture change.
Remember, smaller mushrooms often have a more delicate flavor, while larger ones are meatier, so pick based on your recipe needs.
3. Harvest in the Morning for Best Results
Many growers swear by harvesting mushroom blocks in the morning when the mushrooms are most hydrated.
Overnight, the substrate absorbs moisture, making the mushrooms plump and crisp.
Morning harvests also mean the mushrooms haven’t been dried out by the sun or heat lamps yet.
If you can’t harvest in the morning, just do it before you mist the block again so the mushrooms are dry.
Step-by-Step Guide on How to Harvest Mushroom Blocks
Now that you know when to pick, let’s walk through the actual process of how to harvest mushroom blocks without damaging the mycelium.
This is crucial because a clean harvest means your block can produce more flushes later.
1. Gather Your Tools
You really only need two things: a sharp knife or scissors, and clean hands or gloves.
Some growers prefer to twist the mushrooms off, but using a knife is cleaner and prevents tearing the substrate.
Make sure your blade is sterilized with rubbing alcohol before you start.
This prevents introducing bacteria or mold to the block while you harvest mushroom blocks.
2. Twist or Cut at the Base
For most mushrooms, especially oysters, a gentle twisting motion at the base works perfectly.
Hold the stem near the substrate and twist slightly until it pops free.
If you’re dealing with clusters, cut the entire cluster at the base to avoid leaving stubs.
Leaving stubs can invite rot, so always remove the full stem when you harvest mushroom blocks.
3. Don’t Pull, Gently Detach
Pulling hard is a common rookie mistake because it can rip up the mycelium network.
Instead, use a slicing motion with your knife to separate the mushroom right at the substrate surface.
If you do twist, make sure it’s a slow, controlled turn.
The goal is to keep the block intact so it can recover and fruit again.
4. Handle Mushrooms Gently After Harvest
Once you harvest mushroom blocks, handle the mushrooms by the cap, not the gills, as gills are fragile and bruise easily.
Place them in a paper bag or a basket with good airflow, never a plastic bag.
Plastic traps moisture and speeds up spoilage, so keep them dry and cool.
You can store them in the fridge for up to a week, but they’re best eaten within a few days.
How to Get Multiple Flushes After You Harvest Mushroom Blocks
The beauty of growing mushrooms is that one block can give you several harvests, called flushes.
After your first harvest, the block isn’t done, it just needs a bit of rest and care.
1. Clean Up the Substrate Surface
After you harvest mushroom blocks, inspect the top of the substrate for any leftover stem bits.
Gently scrape them off with a clean spoon or knife.
This prevents any dead material from rotting and keeps the surface clean for new pins.
2. Rehydrate the Block
The block has lost moisture during the first flush, so it needs a good soak.
Submerge the entire block in cold, clean water for 4 to 12 hours, depending on how dry it feels.
Use a heavy plate or bowl to keep it submerged, as blocks tend to float.
After soaking, drain well and return it to your fruiting area.
3. Rest and Wait for New Pins
After you harvest mushroom blocks and rehydrate them, give them a few days of rest.
Keep humidity high and temperature steady, and you’ll see tiny pins forming within 7 to 14 days.
Some blocks can produce three to five flushes, though each one will be smaller than the last.
The second flush is often the most flavorful, so don’t stop after just one harvest.
Common Mistakes to Avoid When You Harvest Mushroom Blocks
Even seasoned growers make errors, so here are a few pitfalls to steer clear of.
Avoid harvesting all mushrooms at once if they’re not all mature, pick them individually as they ripen.
Don’t water the block right before harvest, as wet mushrooms are more prone to bruising.
And never leave overripe mushrooms on the block, as they’ll release spores that can trigger allergic reactions and reduce future yields.
By keeping these tips in mind, you’ll get a clean, healthy harvest every time you harvest mushroom blocks.
So, How Do You Harvest Mushroom Blocks Properly?
You harvest mushroom blocks by choosing the perfect moment, using clean tools, and detaching mushrooms gently at the base.
Timing is everything, and a careful technique protects the mycelium for future flushes.
Remember to check daily for cap shape and veil, harvest in the morning, and rehydrate after each flush.
With a little practice, you’ll master how to harvest mushroom blocks and enjoy a steady supply of fresh mushrooms from a single block.
So next time you see those mushrooms ready, don’t wait, grab your knife and enjoy the fruits of your labor.