Thursday, December 1, 2011

Some thoughts on Oyster cultivation

I have been experimenting a lot the last 6 weeks with growing oyster mushrooms- and finally had some success.  Time to jot down a few of the things I have learned.

Happy oysters (pleurotus ostreatus) 15 days after inoculation!
Second harvest of oysters growing already on day 19.

  1. Mushrooms really care about their environmental conditions.  Hit the sweet spot for temperature, light, humidity and airflow, and they are champs.  Too high or too low in any 1 variable and you have sadness (and no mushrooms).
  2. Oyster mushrooms will grow on lots of things.  So far I have seen good growth on: shredded paper, coffee chaff, coffee grounds, coffee jute bags, hardwood pellets, and rye grain.  Nothing surprising here, but neat to see it.
  3. Too much moisture in your substrate (growing material) is a real killer.  Better to have non- sterilized substrate at the right moisture than sterilized and too wet.  
  4. If a culture is given the right conditions it will grow like crazy.  I made up 8 containers with different moistures, materials, etc.. and a couple grew like crazy.  Just 7 days after mixing the spawn into freshly sterilized rye grain primordia was already forming.  I harvested 10 ounces of mushrooms from 1 block on day 15! (see first photo).
  5. Spawn bags with a filter patch are pretty awesome.  Limits contamination and allows fresh air in.  Totally worth the cost (~$0.50/bag).
  6. You can do a lot without a HEPA hood, but having one exponentially increases what you can do.  At $1,000+ however, they ain't cheap.  Note- if you are reading this and make HEPA hoods- I will be happy to write a lot about how great your hood is if you are feeling generous.... :)

Tuesday, November 15, 2011

Growing Oyster Mushrooms - Cloning!

Cloning a sheep seemed a bit hard, so I figured I would start with a mushroom.  Anyway, how many Dolly's do we need?
Many mushroom species are ideal candidates for vegetative growth (or cloning if you prefer) since they naturally grow via mycelial networks.   
The basic idea is pretty simple.  Take a healthy, freshly picked mushroom, cut off a chunk of it, place it on a food source that the mushroom loves, and watch it grow!  Once the mycelium has grown to cover your growing medium, then you can take chunks of that medium and inoculate new food supplies.  Let the new chunks grow out in their fresh food source and repeat.  A tenfold expansion is common- so in 3 generations you can go from 1 to 10 to 100 to 1000.
Presuming you are adept at handling a few minor details like contamination, proper temperature, humidity, carbon dioxide levels, and supplying fresh sources of food as the mycelium needs- you can get some amazing results. 
In theory, you can go from a single chunk of mushroom to thousands of pounds in a few months, and millions of pounds within a year, becoming fabulously wealthy and successful. 
The reality of it is that while oyster mushrooms are vigorous, they have specific climactic needs.  Go outside the ideal window for any of a bunch of variables and you get a pile of mold, instead of tasty mushrooms.  I am not expecting success- but I have hope.  My goal is to just get the damn mycelium to grow successfully enough to get one new mushroom from it.

My protocol is based primarily off the work of Paul Stamets and Rush Wayne.  Paul has done more to encourage mushroom cultivation than anyone else in the US, and his books remain the bible of mushroom cultivation.  You can find links to them on the Amazon list on the right sidebar.  Rush Wayne has a neat protocol that uses the power of hydrogen peroxide to help prevent contamination.  This allows you to grow several species without the use of a HEPA hood- which can be a pretty expensive bit of equipment.

I made up agar plates using the malt extract agar mix from Fungi Perfecti, with the addition of 3 wood pellets and hydrogen peroxide.  For a full explanation read the work of the experts- they cover this far more thoroughly.
The recipe is as follows: (UPDATE- this seems to be a bit too much hydrogen peroxide- the growth onto agar is VERY slow- I will be trying it again with less peroxide).
(For 10 petri dishes)
25 grams Malt Extract Agar mix
3 wood pellets (hardwood pellets used in pellet stoves)
500ml filtered water
4ml 3% hydrogen peroxide

Combine the agar mix, pellets, and water in a flask/jar.  Cover loosely and pressure cook at 15 psi for 20 minutes.  Let cool until the agar mix is hot but you can handle it (say 110-140 F).  Add your hydrogen peroxide to the mix, and swirl it to mix.  Pour the agar into 10 clean petri dishes and let cool.  

Congratulations- you now have agar plates ready to use- that are in theory fairly resistant to contamination!

Oyster mushroom tissue on agar- day 2.
I then picked a healthy oyster mushroom and got out my surgery kit.  Or at least a scalpel and flame.  Flame sterilize your scalpel and cut open the mushroom.  The goal is to get a chunk of tissue from the inside of the mushroom (ideally near the cap) that has not been exposed to contaminants that may be on the outside of the mushroom.
Take your clean chunk of mushroom and place it on the center of an agar plate.  I did this to 5 plates- so hopefully at least a couple will be successful. 
I wrapped the other 5 plates in parafilm to help prevent contaminants from entering (although supposedly you don't need to do this), and put all ten of the plates in an open bag on a shelf.  65-75 is probably a good temperature for the mycelium to grow.

Day 8- primordia forming- but little growth onto agar.
Now we wait- growth should occur within a few days, and before two weeks have passed the mycelium should be ready for transferring to a larger volume, and further expansion of mycelial mass.

Day 2- Not much to report.  Possibly the slightest bit of growth onto agar- but not much.

Day 5- Little bumps forming on mushroom chunk- Primordia?  No infections yet.

Day 8- So the agar seems to have a bit too much hydrogen peroxide in it.  The mushroom is forming primordia from the initial chunk- but is very reluctant to grow out onto the agar.

Day 15- green mold growing on 1 plate.  Bummer!

Day 15- One plate has green mold growing on an edge- so I dumped it in the compost.  The rest are still contamination free- and actually starting to show good mycelial growth onto the agar.

Day 16- mycelial growth really getting going on this plate.

Friday, October 21, 2011

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..

Friday, October 14, 2011

Velvet-footed Pax (Tapinella atrotomentosa)

Season: Summer to fall
Edibility: No.  Possibly poisonous, although I can not verify that.
Defining Characteristics:  Growing on stumps of conifers.  Shares some characteristic of oyster mushrooms (gills running down an off-center stem, growing in clusters), but has the unique feature of an extremely hairy stem.  Yellow to brown spore print.
Also known as: Paxillus atrotomentosus

Growing on a dead conifer stump
It is not every day you find a mushroom that is not just hairy, but downright furry.  The Velvet-footed Pax  has a stem that looks like the fur of a mouse or wooly-bear caterpillar.  It is known to primarily grow on dead conifer stumps, and this is where I encountered it myself.  It is not reported to be edible.

You probably won't see this little bugger often, unless you happen to spend your spare time in recently logged pine forests.

For more information check out one of these links: Messiah College, or Mushroom Expert.

Note the extremely hairy stem!

Tuesday, October 4, 2011

Yellow Parasol (Leucocoprinus birnbaumii)

Season: Year round in your house plants!
Edibility:  NO
Defining characteristics:  Growing indoors next to your houseplant.  Entire mushroom is bright yellow with a small ring on the stem.  Small spots/bumps on the cap with often a dark center.
Confused with: Those tiny yellow paper umbrellas you find in tropical drinks.

Yellow parasol visiting my jade plant.
This fascinating little guy popped up in my jade plant last weekend.  I thought it quite friendly of him to visit, given that I love fungi so much and rarely get a visit from a new species inside my own house!

A quick internet search for yellow mushroom houseplant brought up plenty of information on my visitor.  There doesn't seem to be a single agreed upon common name for the Leucocoprinus birnbaumii, so I am calling it the yellow parasol since is seems the most fitting option to me.

Apparently they grow outside in the south on rich compost or manure quite frequently.  Here in the northlands they show up in greenhouses and houseplants fairly often.  Once they are in your pot- you probably won't get rid of them- so don't bother trying.  I will see how often this guy produces a fruiting body and report back here whenever he does.

Note the ring on the stem.
Anyway- they are NOT edible- so don't try.  Enjoy their beauty while it lasts- as mine appeared matured and wilted in about 4 days total.

Read more from:  Tom Volk's Fungus or the Mushroom Expert 

Sunday, October 2, 2011

Painted Bolete (Suillus pictus)

Season: Mostly fall, occasionally in the summer.
Edibility: Edible with caution, if not entirely delicious.
Defining characteristics:  Reddish hairy cap, yellow pores, a veil that may not completely disappear  with age, found predominantly near eastern white pine.
Sometimes confused with:  Boletes and Suillus are a complex group of mushrooms.  While there are many tasty boletes out there, and most are not dangerous, there are some poisonous ones to watch out for.  My advice is to take it slow with the boletes, go steady for a while before you get real serious and make a permanent commitment.
Spore Print: Brown
Also known as: Suillus spraguei

Painted boletes strutting their stuff.
Note the veil covering the pore surface on the left,
and the remnant veil on the right.

The painted bolete is one of the most recognizable and attractive suillus.  Suillus are a group of ~50 species in the larger grouping of boletes. (Genus Suillus within the order Boletales if you want to get taxonomic). Suillus are distinguished by generally being found near conifers, having a veil covering their largish pores, and being rather slimy (in addition to the primary characteristic of being a pore bearing mushroom instead of gill bearing).

The painted bolete fits most of those criteria, except it is generally not particularly slimy, a feature that I appreciate.  They often appear in fairly large numbers, and I have only ever seen them around white pines here in Rhode Island.  They tend to become infested fairly quickly with bugs, so select prime specimens!

If you are a novice forager, I would exercise caution before eating any bolete.  You can probably get away with it, but a mistaken ID could leave you under the weather for a while, or more likely, with a horribly acrid taste in your mouth for a long time (yes this has happened to me).

Often when trying to identify your bolete down to the species one of the final tests is to take a small bit into your mouth, chew it a couple times and spit it out (I normally rinse my mouth out afterwards with a shot of vodka- I figure it helps sanitize any critters, and helps me out to boot). This allows you to tell if there is no taste or an acrid or bitter taste.  If it taste bad raw, it is probably not going to taste better after cooking (although there are some exceptions to that rule).
Painted bolete in the woods.

Please note that you should only do this taste test after narrowing it down to a group of non-poisonous mushrooms, and you should spit out everything you put in your mouth.  Eating raw mushrooms is not recommended, period.  Too much bacteria, virus, and animal poop hangs out in the woods to risk raw consumption, not to mention that our bodies are not equipped with the ability to digest raw mushrooms.

I personally am not a huge fan of the painted bolete as an edible.  After sautéing it pretty hard in butter and oil, and seasoning it well it taste all right- but at that point you have pretty much made a mushroom fry, and what doesn't taste good fried and salted?  My wife thinks they are pretty tasty though, so don't take my word for it.

As usual, for better information and advice on this species I encourage you to read the following: Mushroom Expert, Taste of the Wild, or Wikipedia.

Friday, September 30, 2011

Matsutake (Tricholoma magnivelare)

Season: September - October
Edibility: Unique and delicious.  Not for beginners due to potential confusion with dangerous species.
Defining characteristics: Found near Eastern Hemlock and Jack Pine (at least in the new england region). Intense aroma that is decidedly Matsutake- think a combination of spicy cinnamon and musty socks.  I am not aware of any other mushroom that smells like this- rich, earthy, spicy, and almost intoxicating.  Growing very close to the ground, often with the stem several inches deep.  A veil covers the gills when immature, leaving a ring on the mature mushroom.  There are often dark markings/stains on the cap and base of the stem.

Young and mature Matsutake.  Note the ring on the
specimen on the right, and veil on the left.
Matsutake is one of the most highly sought after mushrooms in Japan.  The unique aroma, taste, and beauty of this mushroom have led to it being valued at hundreds of dollars a pound in Japan for prime specimens (young with a full veil and in pristine condition).  The primary commercial harvesting areas are in the Pacific Northwest, however there are Matsutake to find here in New England.  I have not found them in Rhode Island yet, but they are reported to be found on Cape Cod, and I have found them in Maine.  They are also reported to be fairly common in parts of Quebec.

High quality Matsutake next to a couple just starting to poke
out of the ground (this is a good stage to harvest them at)
You definitely want to be careful with identifying Matsutake.  There is a condition known as mushroom collecting fever, where an excited forager thinks every mushroom they find just happens to be the long sought after delicious delicacy, with little regard to checking its defining characteristics.  I only ate Matsutake that I collected after three years of searching for, and finding them.  The first two years I collected what I thought where Matsutake (and now know they actually where), took photos, and read up on them.  I was not fully convinced so I chose not to eat them.  It wasn't until this year when I found the same mushrooms growing in the same spots, with the same aroma, and a couple more years of accumulated wisdom that I finally was sure of what I had.
Matsutake on the left, golden chanterelles on the right.

They are delicious, and the aroma is amazing.  A little bit stinky, a little bit spicy, and a lot heady.  After sautéing in a bit of butter and a dash of salt it is without comparison.  There is a firm texture with a taste that is very complex.  It is hard to describe it except as Matsutake-like.

David Spahr has an excellent description of the Northeastern Matsutake on his website, and you can also read more at the Mushroom Expert or Tom Volk's website.