By Summer in Australia means long evenings, full fruit bowls and a warm kitchen. Warmth happens to be exactly what fermentation needs. Talk to any female surgeon who works in gut health, and you’ll probably hear the same advice: what you eat every day matters more than any quick fix! A colorectal and prolapse specialist will tell you that comfortable digestion starts with fibre, fluids and variety. People booking a colonoscopy in Melbourne often ask what they can do at home, and fermented foods often come up. So here’s how to make a few of them yourself, safely and cheaply.
What is fermentation all about?
Fermentation happens when bacteria or yeasts break down sugars in food. In sauerkraut and kimchi, lactic acid bacteria turn those sugars into lactic acid. The acid preserves the vegetables and gives them their tang.
The research is promising, but it’s still early. In 2021, a Stanford University study published in Cell found that 18 adults who ate about 6 servings of fermented food a day for 10 weeks had more diverse gut microbes and lower levels of several inflammatory markers. A matched high-fibre group didn’t show the same change in diversity. It was a small trial, though, and it doesn’t prove fermented foods prevent disease. Think of them as a helpful addition, not a cure.
Sauerkraut is the easiest place to start
You need cabbage, salt and a clean jar. That’s it!
- Shred one cabbage finely and weigh it.
- Add salt at about 2% of the cabbage’s weight, so roughly 20 g per kilo.
- Massage it for five to ten minutes until it releases its liquid.
- Pack it tightly into the jar so the brine covers the cabbage.
- Weigh it down with a small zip-lock bag of water.
In summer, keep it out of direct sun and taste it after three or four days. Australian kitchens can hit 28°C or more, which speeds fermentation up and can make it go soft. A cooler cupboard or the laundry often works better.
Kimchi brings the heat
Kimchi follows the same principle as sauerkraut, with wombok, garlic, ginger, spring onion and Korean chilli flakes (gochugaru). It’s ready to eat in 2-5 days, then it keeps developing in the fridge for weeks. Going easy on the chilli at first makes sense if spicy food upsets your stomach.
Yoghurt and kefir for the fridge door
Homemade yoghurt only needs milk and a few spoonfuls of plain yoghurt with live cultures as a starter. Heat the milk to about 85°C, cool it to around 43°C, stir in the starter and keep it warm for 8-12 hours.
Milk kefir is even easier. You add kefir grains to milk, leave it on the bench for about 24 hours, then strain it. On a hot day it can be ready in less time, so check it early.
Try out kombucha
Kombucha takes a little more patience than sauerkraut, but once you get your first batch going, it practically runs itself. You’ll need a SCOBY (a rubbery disc of bacteria and yeast, short for symbiotic culture of bacteria and yeast) and about a cup of starter liquid from a previous brew. A friend who brews can usually spare one, or you can buy them from health food shops.
For a 2 litre batch:
- Boil 2 litres of water and steep four bags of black or green tea for about 10 minutes.
- Stir in roughly half a cup (about 100 g) of plain white sugar until it dissolves. The culture eats the sugar, so don’t cut it back or swap in honey or sweeteners.
- Let the tea cool completely to room temperature. Hot tea can kill the culture.
- Pour it into a large, clean glass jar, then add the SCOBY and starter liquid.
- Cover the top with a tea towel or paper towel and secure it with a rubber band so it can breathe while keeping fruit flies out.
Leave it somewhere warm and out of direct sun for 7-14 days. In an Australian summer it often ferments at the faster end of that range. From day five, slide a clean straw under the SCOBY and taste. When it’s tart but still slightly sweet, it’s ready.
Keep the SCOBY and a cup of liquid aside for your next batch, then bottle the rest. For fizz and flavour, add a few pieces of fruit or a slice of ginger to each bottle, seal them and leave them on the bench for 2-3 days before you refrigerate. Open each bottle once a day during this stage to let pressure escape, since sealed kombucha can build up a surprising amount of gas!
Use glass for brewing. Some glazed ceramics and metals can leach into the acidic liquid. A healthy SCOBY can look lumpy, brown or stringy, and that’s normal. Fuzzy, dry spots of white, green or black mould are a different story. Throw the whole batch out, culture included, and start fresh.
Where fermented foods fit in your diet
Fermented foods work best alongside plenty of fibre. Australia’s NHMRC recommends about 25 g of fibre a day for women and 30 g for men, yet many adults fall short. Vegetables, legumes, wholegrains and fruit still do most of the work.
They also can’t replace screening. Australia’s National Bowel Cancer Screening Program now sends free test kits to people aged 45-74. And you should get your first colonoscopy at age 45. If you notice bleeding, a lasting change in bowel habits or unexplained weight loss (especially if you have a family history of bowel cancer), see your doctor or colorectal surgeon, whatever your age.
Healthy gut habits and when to see a specialist
Making fermented food at home is cheap, creative and a lovely summer project for the whole family. Start with sauerkraut, keep things clean and let your taste buds lead. For ongoing symptoms, a GP referral to a colorectal and prolapse specialist can give you clear answers. Many patients prefer to see a female surgeon for sensitive concerns, and that’s completely reasonable. If you need a colonoscopy in Melbourne or anywhere else, a good diet makes a great foundation, but it’s no substitute for proper care.