Margin’s Mushrooms Woy Woy


Kim Margin comes from a considerable line of soft drink and ice cream manufacturers dating back to 1906 – the slogan ‘Make Mine  Margin’s’ is still familiar to many. In the mid-80s the business came to and end and Kim was left with an idle ice-cream factory. He experimented with different reinventions of the factory which is housed on his property in Woy Woy, including using it as a storage facility for homemade wine. But it wasn’t until he converted it into a space to grow mushrooms that the factory was truly reborn. Its three small cool rooms were modified to provide the humidity necessary for mushroom farming, and in 2009 Margin’s Mushrooms emerged.

Sadly, today fresh mushrooms are so hard to come by they are considered by many to be a novelty. That’s why when people come across Margin’s Mushrooms they swoon! The factory’s growing capacity of 200 blocks was soon unable to keep up with demand, so the business relocated to the old Woy Woy abattoir, which had lain dormant for several years. The building’s structure was solid with sealable rooms. To create the perfect mushroom-growing environment, the Margin’s just had to provide the right amounts of water and air to the space. After these modifications were complete, the new premises was ready to accommodate 1000 blocks.

Today, the Margin’s grow white mushrooms to button, cap and flat stages, as well as Swiss Browns and Portobellos. They only use certified-organic blocks, called Phase 3 Blocks, which are sourced from a major supplier in Singleton. The blocks arrive as compost blocks, already colonised with mycelium. This is the vegetative part of a fungus and is a mass of branching threads. Mushrooms are the fruit of the mycelium.

The blocks are covered with peat moss, which is a labour-intensive job for the family when you consider the number of blocks they cultivate. Next, the blocks are watered for three days to prepare them for the first flush. This first harvest can take several weeks. Each block produces four flushes, about a week or so apart, after which it is removed and resold as garden compost.

Much of the work in mushroom farming revolves around keeping contaminants and insects at bay. Ideal growing conditions are moist and warm, which is also the favourite environment of many pests. Margin’s Mushrooms are completely chemical-free, so hygiene and vigilance are the family’s main weapons in fighting off intruders – one insect in a room can multiply to hundreds within just a day or two. The positive pressure of the rooms helps keep insects out and for any sneaky ones that make it inside, there’s a bright light and sticky paper!

Margin’s Mushrooms is very much a family affair. Kim and his wife Chris spend most of their time at the farm and personally man their stalls at various markets. Their two sons are also involved in the business and when there is a big flush, it’s all hands on deck.

The mouth-watering mushrooms have quickly achieved a loyal following. They are available at several Sydney markets, including Redfern and North Sydney. Locally, you can find them at Avoca Beach Growers’ Market and Mangrove Mountain Country Market. Their mushroom compost from finished blocks is also popular with home gardeners and available for purchase. After supporting four flushes of mushrooms, it is weed free, well drained and incredibly fertile. Perfect for the vegie garden! Stop by the farm on Blackwall Rd, Woy Woy to buy Margin’s Mushroom Compost direct, or head to your local markets to discover what a revelation really fresh mushrooms can be.


Mushrooms are best stored in a brown paper bag in the crisper section of the fridge. Don’t wash the mushrooms before storing as this can cause them to ‘sweat’ and deteriorate. You will notice that mushrooms as fresh as Margin’s are will store a lot longer than those bought in a supermarket!


With mushrooms, the less they are handled, the better. If you are eating them raw wipe them over with a damp paper towel. If you rinse them, do so under cold water and quickly pat them dry with paper towel. The best method is to give them a gentle brush with a pastry brush to loosen any dirt. Mushrooms do not need to be peeled and yes, the stalk is there to be eaten too.

Visit Website
Farm: (02) 4341 3003
Home: (02) 4344 2468
Opening Hours
The farm is open to the public from 9am to 12am Monday to Saturday OR 
when the open signs are displayed out front. 
Farm Location
Lot 151,
171 Woy Woy Road
Woy Woy, NSW, 2256



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