An estimated 20 to 40 per cent of food - particularly fresh produce - is thrown away purely for aesthetic reasons.

This alarming amount of waste is the backbone of a Healthy People Illawarra campaign, Hidden Harvest, a community-based initiative that raises awareness about food waste and its environmental impacts and social problems.

This may come as a surprise to some, but despite an increasing amount of people opting to go organic, this is a reality for Calderwood organic food farm, Mahbrook Organics.

Farm owners Adam and Chris Bridger said at least 20 per cent of their product doesn't make it into the shopping trolley.

"People shop with their eyes," Chris said.

"As an organic business it's frustrating because organic field production is lower because we don't use pesticides or chemicals, and we end up having to sell some produce as seconds, just because a tomato has a small blemish, or there are a couple of holes in the cabbage leaves.

"It doesn't matter what a vegetable looks like, it still tastes good, it's still healthy and (consumers) are not eating chemicals."

Mahbrook Organics have partnered with Hidden Harvest and have donated the unsaleable but edible food to the initiative for culinary pop-up dinners held in Thirroul.

Founder of Hidden Harvest, Berbel Franse, said oversized zucchinis, cucumbers with a slight bend and chillies with a blemish or two were just some of the foods that made up the menu at the dinners.

"It links people with their food and generates that discussion on just how much yummy food goes to waste," Ms Franse said.

"(We) aim to inspire and engage the community to tackle food waste in their everyday routines.

"It also highlights some of the environmental aspect of food waste going into landfill. This gives off the greenhouse gas methane, which can be avoided by composting."

Ms Franse said she hoped that the initiative would also encourage businesses that have surplus produce or produce they couldn't sell, to donate to local organisations that provide food for the needy, such as the Denny Foundation or the House of Hope Food Barn.

To find out more or to see upcoming events follow Hidden Harvest on facebook.com/ HiddenHarvestAustralia.