Good bugs, bad bugs – preserving and fermenting food in glass National Science Week 13 to 21 August.


The Food Safety Information Council today invited the community to take part in their National Science Week event about ‘Good bugs, bad bugs – preserving and fermenting food in glass containers.’ The event will be held live on Facebook with our member Environmental Health Australia on Saturday 13 August at 3pm and then available as a video.

Associate Professor Julian Cox, the Council’s Scientific Director, said we hear a lot about the risks of those bad bugs that can give you food poisoning but there are also good bacteria that help us digest the food in our gut as well as ferment and preserve food.

‘The theme of this year’s National Science Week is ‘Glass more than meets the eye’. Glass is a great container for preserving and fermenting food as it can be kept clean easily and forms a good airtight seal,’ Professor Cox said.

‘Fermented food and drinks undergo controlled microbial growth and fermentation where microorganisms like yeast, moulds and bacteria break down food components like glucose into organic acids or alcohol.

‘You’d be surprised how many of the everyday foods we eat are fermented. There are the usual suspects like yoghurt, cheese, bread, beer and wine, but also sauerkraut, kimchi, kefir, miso and tempeh, even coffee beans and chocolate!  Originally many of these foods were fermented to preserve surplus food through winter but now many are appreciated by different cultures for their unique sensory qualities – flavours, taste, texture and appearance.

‘While many fermented foods are considered beneficial, they can be risky for some people. Be aware that some people can react to fermented foods especially if they have reactions to histamine or are taking antidepressants which react with tyramine, which some of these foods can contain. Such foods can be hazardous if people are allergic or immunocompromised. These foods can also cause bloating and discomfort in some people.

‘When fermenting or preserving food always follow these food safety practices to make sure good bugs flourish while bad bugs don’t grow in your fermented food:

  • Always wash your hands before preparing any food: wet hands under running water, soap thoroughly up to your wrist and rub between your fingers, rinse under running water and dry thoroughly on a clean towel.
  • Wash your containers, chopping boards and utensils before use in warm soapy water, rinse well, and leave to dry thoroughly, or wash in the dishwasher.
  • It is recommended to use a commercial starter culture and to follow the manufacturer’s instructions including fermenting at the recommended temperature. Use a new starter culture for each batch and don’t be tempted to ‘backslop’ a starter culture from an existing batch to make a new one as you could transfer undesirable microorganisms, or the fermentation may not proceed properly.
  • Only use pasteurised milk for fermented dairy foods and never try to make your own fermented meats at home as this is far too risky.

There are many other ways of preserving food in glass such as jams, pickles, relishes and chutneys which include ingredients such as salt, vinegar (acetic acid), sugar, spices and water.  Here are some more food safety tips on these processes:

  • Pickles should be placed in a clean jar, topped up with vinegar or a vinegar mixture containing at least 50% vinegar.  Where possible, use Australian recipes as US and European vinegars are stronger than ours. Pickles can be stored in the fridge, or if you store them at room temperature, they must be pasteurised by placing in a waterbath with the lid lightly screwed on and the water heated to above 85°C, measured with a thermometer.
  • Jams, chutneys and relishes can be hot filled straight from the pot at a temperature greater than 85°C, sealed and the jars inverted for 3 minutes o sterilise the lid.
  • When preparing vegetables and herbs in oil it is really important to get the recipe correct to prevent the survival or even growth of dangerous bacteria such as Clostridium botulinum which causes botulism. Vegetables and any fresh herbs should be soaked in vinegar overnight with a ratio of 300g of vegetables and any fresh herbs to 100ml of vinegar, drain the liquid, then you can add oil. Jars are best stored in the fridge to minimise the risk of spoilage.  Dried vegetables, herbs and spices can safely be added to oil without the vinegar soak and then stored at room temperature.

‘Finally, we invite teachers to register for our online briefings on Wednesday 10 August at 3.30pm on how to prepare classroom material, a recording will also be available for those that can’t attend. We will also be working with First Nations to broadcast programs about traditional food preservation methods on National Indigenous Radio throughout National Science Week. Our thanks to the Australian Government for their grant funding these events,’ Professor Cox concluded.

For more information:

Fermenting food and drink at home

Teacher resources for National Science Week

CSIRO advice on pickling For more information on how to make and pasteurise pickles

Media contact: Lydia Buchtmann, Food Safety Information Council, 0407 626 688 or