Growing Oyster Mushrooms 2011

It is late October, and the mushroom season is on the verge of ending in Rhode Island. Normally this would be a sad time in mushroom land, as there are a good 7-8 months before wild mushroom foraging really returns to New England.

But not to fear- for we can grow mushrooms indoors (and no, not those mushrooms)!  There are several species that can be grown fairly easily on sawdust or cellulose based materials (paper, wood chips, cardboard, coffee waste, etc...) including oyster mushrooms, shiitake, lions mane, hen of the woods, and more.

Full disclosure here- this end of mushroom season gloom hits me every year, and I have tried to grow mushrooms each of the last 3 years as the cider and pumpkins appear.  The first year I grew an oyster mushroom kit on coffee grounds and actually had a little success.  Probably 8 ounces of oysters that were pretty darn tasty- but not a great return on a $24 investment (plus shipping) and over a month of work.

The next year I decided that I wanted more mushrooms for my investment, so I spread the spawn over 4 buckets.  Seemed like a good idea.  End result was not enough spawn per bucket, and no mushrooms grew.

The year after I ordered my oyster spawn, but I was busy and ended up not inoculating the spawn for 8 weeks.  By the time I mixed the spawn, it was pretty tired and the mycelium never took off.  No mushrooms.

This brings us to 2011- this year.  With all the mistakes I have made and lessons learned, I am convinced this will be the grand success.

I will write up a summary when done- but for now here are the results as they happen.

September 27th - Day 0

Oyster mushroom spawn from Fungi Perfecti.

Two oyster mushroom kits ordered this year- for twice the fun!
I decided to use some different growing materials- coffee jute bags (that hold green coffee), and coffee chaff (a byproduct of roasting coffee- a full day of roasting creates a full bag of husks/parchment/bits of coffee beans).

I knew that I couldn't spread the spawn too thin, and that I needed to pasteurize the growing substrate.
So I heated a big pot of water and boiled the coffee chaff and bags for 15 minutes.  (In retrospect I should probably have boiled it for longer- perhaps 45 minutes to an hour)?

Then I mixed two smallish bags of boiled chaff (about 2 pounds each) with 1/4 bag of spawn each, and 1/4 of a bag of spawn in each of 6 boiled jute bags (I spread the spawn on the open jute bag then rolled them up tight).

Here comes another mistake.  I put the chaff and jute bags into clean plastic bags, twisted the end of the bag and tucked the end under each bag.  I figured that since oyster mycelium grows well with high carbon dioxide levels, having a nearly sealed bag would not only keep the moisture in, and contamination out, but would allow a lot of carbon dioxide to build up in the bags- promoting rapid mycelial growth.

Spawn on jute bag before rolling it up, and rolled bag.

I put all the bags down in my basement (which was at about 72 degrees) on wire racks.  Fairly dark and humidity around 60%.

An important detail- I used one of the spawn bags to hold one of the jute bags, which had a filter patch on it- allowing some air flow, but not contaminants into the bag (it also had mycelium on the inside of the bag which might have helped).  Finally when closing the two bags of coffee chaff, I didn't twist the bag ends I just folded the end under the bag loosely- which allowed more air flow.


October 4th - Day 7
Signs of mycelium growing in spots in all the bags.  Looking good.

October 10th - Day 14
Some trouble.  The mycelium that was growing robustly a few days ago, has slowed down and apparently decreased in several of the jute bags.  The 1 bag that has the filter patch shows some signs of green mold near the bag opening, but also has excellent mycelial growth.  The two bags with chaff are both growing pretty well- the mycelium is starting to hold the chaff together in a brick.

October 14th - Day 17
Primordia is starting to form in one of the bags with chaff, and on the jute bag that has the filter patch!
I moved the two chaff bags, and the jute bag upstairs.  Oysters need light to fruit, and the warmer temperatures also help with cropping.

Jute bag colonized with oyster mushroom
spawn.  Primordia forming low on bag. 

I cut the bag down to the level of the chaff, put two chopsticks in each log (to hold the humidity tent up) and covered the logs with a plastic bag with some holes in it to keept the humidity high.  The challenge is to maintain high humidity AND good airflow.  Without fresh air the oysters grow long stems, and no caps.  But if the humidity drops too low, they dry out, crack and stop growing.  A tricky balance.
I placed one chopstick in the jute bag and covered it in a humidity tent.

Fully colonized brick of coffee chaff.  Ready for fruiting!

October 18th - Day 21
Primordia/baby mushrooms are growing on the jute bag and one of the chaff bags!

Day 21.

October 20th - Day 23
Primordia stopped growing on the chaff bag- not sure if the humidity dropped too low.
Mushrooms almost ready for harvesting on the jute bag- just one cluster but it is a start!

Day 23- almost time to pick them.

October 21st - Day 24!
Time to harvest my first oysters of 2011.

Oysters are dropping spores (visible on table).  

Last night spores started dropping from the cluster, a sure sign that the mushrooms are just about mature.  This morning there are lots of spores- harvest time!  They are not as big as I would hope- but at least there is something.  There are a couple mushrooms on the chaff bag that are growing huge long stems.  Presumably too high CO2.  I created a larger humidity tent from a big plastic bag- so hopefully that will help some.

Chaff brick.  Note elongated stems on mushrooms in front.
Too high CO2 levels most likely in humidity tent.

October 24th - Day 27
2.5 ounces harvested from initial flush- pretty tiny harvest.
The second coffee chaff brick is starting to produce primordia- hopefully more mushrooms by the weekend!

October 25th - Day 28
Pinheads forming on both of the chaff bricks.  I tossed two more of the jute bags into the compost as they were getting moldy.  Probably not enough airflow, plus not a high enough inoculation rate.  Possibly not enough sterilization as well.
At least 1 or 2 of the other jute bags may still provide mushrooms though!

October 28th - Day 31
Of the 7 jute bags I inoculated here is where I stand.
-3 have failed.
-2 are on the border- not sure if the molds or oyster mycelium will win.
-1 is looking like it will achieve full colonization in the next week.
-1 has been a rock star with colonization, and produced the nice cluster in photos above.  It hasn't done much since then though- hopefully getting ready for a bigger second flush.
The two chaff bricks are doing allright- forming a few more mushrooms.  I think that a combination of too high CO2 and not enough light are stunting their growth.
I am setting up a grow light to augment the diffuse natural lighting they currently get.  We will see...

November 15th - Day 49
So a few updates to report:
-Of the 4 remaining jute bags 1 is still struggling- but the oyster mycelium may beat out the molds.
- The other three are all fully colonized and showing pin-head formation, but few actual mushrooms.  Not sure if they are still to come, or if there is something I am missing.  The chaff bricks are producing mushrooms in the same growing area- so perhaps there are nutrients missing from the jute bags?
Total harvest since the start of this round is 4.3 ounces.  Not great- but there still looks to be a good bit more.  No signs of contamination/ fungal gnats/etc..