Success mushrooms from the bush

The bush on the Maungatapere property of Greg Rathbun and Tann (Phikulthong) Duangprasit has proved a happy hunting ground for edible fungi.

Over the past five years the couple have built up a successful business, Maungatapere Mushrooms, which is expanding to meet the demand from farmers' markets and restaurants seeking the rich tastes of mushroom varieties. The mushroom business now makes up half their income.

They recently won a gold medal in the New Zealand Outstanding Food Producer Awards.

Tann is originally from Thailand where mushroom foraging is a traditional pastime.

"I grew up in a village in the province of Maha Sarakham in northeastern Thailand and my happiest childhood memories are grabbing a bucket and browsing in the forest along the roadside with my grandparents.

"Traditionally, Thai people use mushrooms as one of their main sources of protein as animal protein is not so available.

"We all grew up with a knowledge of edible mushrooms," she said.

When Greg and Tann bought the avocado orchard, she naturally wandered in the bush on the property and spotted many edible fungi growing on rotted trees.

"Most Kiwis don't realise they have a pantry in their bush," Tann said.

However, caution is needed because there are some New Zealand fungi that are highly toxic and eating a single mushroom can be fatal. Some of these strongly resemble edible varieties.

The varieties being propagated by Tann have had their DNA checked in a Dunedin laboratory for confirmation of their identity and safety to eat.

Tann's first experiments with cultivating mushrooms were pretty rudimentary, but she now has a series of rooms comprising her laboratory, an inoculation room and growing rooms. Containers have also been set up to provide the perfect growing conditions for each variety and they plan to add more.

Mushroom cultivation requires precise science and hygienic conditions to prevent other spores and bacteria contaminating the bags of growing mix.

Tann has to combat the invisible, with the spores of green mould proving a particular contaminant that will ruin batches. Sometimes other moulds will take hold, showing as black, orange and pink in the bags.

"With each bag labelled with a date, I can quickly see when I have had a bad day. The spores might have come in on my clothes after a walk in the bush.

"I have had so many failures. If I only have losses of 10 per cent out of 100 bags, I consider that highly successful. That's how difficult the process is," she said.

In the laboratory, Tann places slices of fungi in Petri dishes and discards any that show contamination with other bacteria. From these tiny slices grows a white shroud, which she then places in bags of wheat in the inoculation room.

Once the mushroom spores start to spread, the wheat is added to the growing bags containing different mixes of sterilised substrate, such as woodchips and straw. Wheat bran is used as a supplement to provide sugar for the mushrooms.

The bags are then moved to the growing rooms where they are kept at a constant temperature according to the needs of each variety. About 150 bags are produced each week.

While the oyster mushroom initially comprised about 80 per cent of production, other varieties were now becoming more prominent.

Tann is particularly excited about some of the Kiwi varieties she is growing to reach commercial quantities.

The Australis oyster mushroom (Pleurotus australis) is almost velvet black on top and is native to New Zealand and Australia.

"It's really yummy and no one else is selling it in Northland. It's pretty exciting as they are still very rare."

Enoki mushrooms (Flammulina velutipes) are also highly sought and Tann is excited to be growing the Golden Enoki, which is a New Zealand variety.

Tann is also growing the tawaka or poplar mushroom (Cyclocybe parasitica), which is popular for its noodle-like texture in cooking.

She also grows Asian and New Zealand shiitake, which are popular but take longer to grow compared with oyster varieties.

"Oyster mushrooms take three to four weeks, while shiitakes take four to five months."

Among the most spectacular is the Coral Tooth or Lion's Mane (Hericium novae-zealandiae), which looks like fine coral and is described as tasting like crab or crayfish as well as having medicinal properties.

In a full-circle process, the depleted substrate from the mushroom business is used as mulch in the avocado orchard.

Tann expects the demand for mushroom varieties to grow as people seek different types of protein for their diets.

"Mushrooms suit all types of diets, including keto and vegetarian. Also, as people grow older they find meat harder to digest so they are turning to mushrooms as a filling alternative." she said.