Blue Oyster Mushroom

The Good Beginner Mushroom

The blue oyster mushroom (pleurotus ostreatus var. columbinus) is a forgiving, fun to grow, fun to watch and delicious gourmet mushroom. The mycelium is aggressive and can be ready to fruit within two weeks. This mushroom is easy to grow and requires little maintenance, which makes it the perfect choice for the beginner hobbyist to grow in a home environment. The mushroom pins can doubles in size every day, which makes it fun to watch grow. The pins start out blue and turn to gray as they mature. 

The blue oyster mushroom has a meaty texture and is a very popular mushroom to grow, simply because this mushroom can use almost anything woody as substrate: paper, cardboard, straw, sawdust, coffee grinds and many other wood-based waste. Its aggressive nature makes it a very fast colonizer. This mushroom is very tasty, contains loads of nutritional content (protein, amino acids, vitamin B, vitamin C, niacin, folic acid) and helps the intestinal tract. It is also a mushroom that does well when kept in the fridge. It can’t be kept very long, and should be consumed within a week. It has the tendency to keep growing even in the fridge once harvested and forming mycelium around the stems.

A disadvantage of the blue oyster is its high requirement for fresh air exchange commonly known as FAE. If the fruit doesn’t get enough fresh air, it will develop a long stem and small cap, which is not presentable but can be eaten none the less without any issues. It is basically trying to reach for fresh air. Providing large amounts of fresh air will produce a short steam but also a meaty thick cap, which is how oyster mushrooms should look.

Another disadvantage is its high spore load. In larger mushroom farms, this can become a problem for the workers, who will require protection; otherwise, the spore load may cause lung or eyes infections and allergies. If the fruit is not cultivated and left alone, it will unload big quantities of spores in the air, which is why the fruit should be picked up as soon as it is ready and put in the fridge or cold storage. Spore load can be an advantage for the hobbyist who wants to harvest spores from a nice piece of fruit body.

Blue oyster grows almost on anything made of wood: Paper, cardboard, coffee grounds, straw, sawdust, wood chips… but the most commonly used and readily available substrates are wheat straw and sawdust, also known as HWFP (hard wood fuel pellets).

Blue oyster mushroom grows aggressively on wheat straw once it is properly prepared. Straw is usually colonized within two weeks.

Supplemented HWFP (hard wood fuel pellets) with a mix of 10% to 20% bran and small amounts of lime and gypsum is also a very good and extremely popular substrate. Blue oyster mycelium loves HWFP, but it takes longer to fully colonize this substrate, because HWFP is heavier and much more dense than straw.

Hobbyist should expect about 2 flushes of blue oyster on straw and 3 to 5 flushes on supplemented HWFP.

The ideal fruiting container for HWFP is polypropylene mushroom bags. Mushroom bags are a bit expensive but can go in the pressure cooker. This bag is a must for HWFP, because HWFP substrate must be sterilized as opposed to straw that only needs to be pasteurized. In addition, mushroom bags come with a filter patch that allows for air exchange; this is very important for mycelium growth, especially in a dense substrate such as HWFP.

For straw, the hobbyist can use polypropylene mushroom bags also, but the cheaper method is polyethylene bag. It is not only cheaper, but also allows the hobbyist to make larger and longer straw fruiting bags, and it allows the bags to be hung on a support. Poly bags cannot go in the pressure cooker and do not have a filter patch. This bag can not be used with HWFP substrate because it cannot go in the pressure cooker.

The poly bag usually comes in a large roll. The hobbyist cuts a piece with the desired length, ties down one end, fills up the bag with straw and spawn and then seals the bag. Once the bag is sealed, the hobbyist makes few small holes about 8mm to 10mm per hole on the bag to allow for air exchange without which mycelium growth will stop. This is a very popular method to make straw bags. It is also from these many holes in the bag that mushrooms will eventually come out.

The last type of container used is also for straw substrate. It is a simple plastic bucket sold in any home hardware store, filled with straw and grain spawn with about 6 to 10 small 8mm to 10mm holes made all around the bucket. The holes are made when the bucket is empty. The holes are then taped. Usually the bucket filled with straw is put into another bucket with no holes, leaving a small gap between the two buckets to allow for air exchange. This is to protect the straw in the first bucket from getting contaminated. The second bucket acts as some sort of a protection. As mycelium colonizes the straw of the fist bucket, the bucket is taken out of the second bucket and put in the fruiting chamber. It is also when the hobbyist removes two or three tapes from the bucket, from these uncovered holes in the bucket mushrooms will come out.

The growing parameters for the the blue oyster mushroom are very interesting because they are in a broad spectrum. The biological efficiency of the blue oyster is among the highest, which is about 100% to 200%.

Incubation: Pinning: Fruiting:
Temperature: 15°C to 21°C Temperature: 10°C to 16°C Temperature: 15°C to 21°C
Humidity: 90% to 95% Humidity: 90% to 95% Humidity: 80% to 90%
Fresh air exchange: 1-2 per hour Fresh air exchange: 4-8 per hour Fresh air exchange: 4-8 per hour
Duration: 10 to 21 days Duration: 3 to 5 days Duration: 4 to 7 days
Luminosity: 500 lux to 1000 lux Luminosity: 1000 lux to 2000 lux

At the fruiting stage, the blue oyster mushroom requires tons of fresh air exchange, also known as (FAE) about 4 to 8 times. If it does not get the FAE, the fruit provided will have long stems, which is not desirable. Oyster mushroom should not be leggy and should have very short stems and nice thick caps; this is accomplished by providing plenty of FAE.

Additionally, for the fruiting phase, if there is not enough luminosity, then the fruit will have long stems. Keeping the parameters in check will provide nice looking fruits and be very satisfying for the hobbyist.

In our shop section, you can find blue oyster related products such as liquid culture, Petri dishes, plugs, grain spawn, sawdust spawn as, well as as the occasional kits ready to fruit. 

Please see our other blogs covering more specific subjects about the fun world of growing mushrooms.