At Gutsy we are PASSIONATE about fermenting in oak barrels, but honestly, they are a pain to use. Oak barrels are expensive to purchase and take lots of maintenance. The barrels have to be constantly kept hydrated or the staves shrink so that the barrel is no longer watertight. However keeping the barrel hydrated is tricky as mould can be an issue if they're not also airtight. If the barrels do dry out and the staves shrink, it takes a couple of days to rehydrate them again before they can be used again. Every few months the staves and rivets need sanding and the hoops need to be readjusted to keep them from leaking. In contrast plastic barrels are cheap to buy, easy to use and no maintenance required. So why do we go to all the trouble of using oak barrels to ferment our sauerkraut and kimchi?
Here's why we're passionate:
1. Microbial Diversity: Oak barrels, when handled & cared for appropriately, harbour beneficial microbes that contribute to the diversity of the fermentation process. The porous nature of wood allows for the colonisation of various probiotics and yeast strains, which can enhance the diversity of the microbial community involved in fermentation. This diversity contributes to a richer flavour profile and additional health benefits through the increased probiotic diversity. Plastic does NOT have this benefit, in fact the chemicals in some plastics can be antimicrobial.
2. Tannins and Other Health/Flavour Compounds: Oak contains tannins and other compounds that leach into the sauerkraut as it ferments for weeks and months. Tannins are polyphenolic compounds found in plants, and they have been associated with various health benefits, including antioxidant and anti-inflammatory properties. These compounds contribute to the overall flavour and health benefits of sauerkraut. On the other hand, BPA, Phthalates and other chemicals that leach from plastic are considered to be harmful.
3. Health and Sustainability: Oak is a renewable resource that captures carbon and, if farmed with care, actually contributes to the health of people and planet. Cutting up trees to make barrels is a relatively easy process that does not involve harmful chemicals. Oak barrels can be used for many years, and while they eventually fall apart after long term use (after many years of maintenance, sanding and readjustment) they have a very long life. When wooden barrels do reach their end-of-life they can be composted back into the environment. We know that plastic is not a renewable resource that does require many toxic chemicals to produce. Plastic also breaks down over time releasing harmful chemicals into sauerkraut and kimchi (and other acidic products) and what do you do with plastic when it's reached its end-of-life?
At Gutsy we've been fermenting our sauerkraut and kimchi in oak barrels for more than a decade. We believe that oak barrels are THE best vessel in which to ferment; oak barrels are beneficial to the probiotics, the people and the planet. Because it is easily accessible, cheap and easy in terms of care & maintenance, almost every commercial sauerkraut and kimchi fermented in Australia is fermented in plastic. What is your sauerkraut and kimchi being fermented in?
If you're fermenting yourself at home, it's often not realistic to ferment in a huge oak barrel. For home use we recommend glass fermentation vessels. Glass isn't quite as beneficial as oak as oak barrels, but it has the advantage of being easy to clean and easy to see how your kraut or kimchi is looking inside (Without removing the lid).