Lactofermentation

Get jars

• Twist-off jars: You can find them for free in the rubbish, for example. You can use any size, for the first few attempts, I recommend smaller jars. However, this method can create so much overpressure in the jar during the first few days of fermentation that the jar explodes (I will check this information again in the next few days!). It rarely happens, but it is possible. You can therefore open the jar very briefly for the first three days to let the CO2 gas out. However, a little oxygen (O2) will then always come in. This slightly increases the risk of unwanted microorganisms multiplying and the contents rotting. One idea: you can prevent oxygen from entering by holding the jar under clean water when opening it briefly! When I use them, I make sure that the food doesn't come into contact with the lid. This is because the seal of the lid contains plasticisers (phthalates), which can be harmful to health - except in the case of blue seals.
• Traditional preserving (ironing) jars: We mostly use these. You need a rubber ring, they are made from natural rubber, food-safe  and normally supplied with the purchase. A 1-litre jar costs around €5. If they are much cheaper and the wires for the lid are thin I would advise against buying them. The wires in IKEA preserving jars are thicker, but they still broke after a while. Bormioli Rocco Fido jars are a recommended and inexpensive brand. But be careful, they break easily when they bump into each other, as the jars seems to be quite thin. Jars from "Le Parfait" are also recommended, but a little more expensive. The rings are cracked after about 3 uses and need to be replaced.
• Newly developed jars for fermentation: If you enter "jars for fermentation" into google, you will find many different models. My sister Hilke has bought jars from "Gefu". They work perfectly, but are expensive: €25 for a 1-litre jar. Hilke writes: "I chose Gefu because I could buy them in the shop. They come in different sizes, and the glass weight hardly lets any chopped food through and is easy to handle with the glass knob.  The max fill indicator prevents overflowing and you can easily see if all the air bubbles are gone. The disadvantages are the price and the unscrewing. The diameter is a bit large for mine, so I can't apply the right amount of force." The glass weight is placed on the vegetables so that they are pressed into the brine. In our experience, it also works well and more easily without these glass weights. However, mould forms in about 10% of the jars. Perhaps we should try using the glass weights again. As an alternative, it is also recommended to place a cabbage leaf on the surface.

Clean the jars, the tools and your hands

The microorganisms that are desirable for fermentation are always present in vegetables. However, undesirable microorganisms can be found on the hands etc. It is therefore safer for successful fermentation to wash your hands with soap and rinse the jar and cutting utensils with hot water.

Prepare the vegetables

The easiest way is to chop the vegetables into chunks, place them in the jar and then fill with a brine made from water and 2.5% salt. So 25g salt to 1 litre of water. Less salt means a higher risk of mould formation, so it is all the more important to work cleanly. Another option, as with sauerkraut, is to grate the vegetables, add 1.5% salt (i.e. 15g per 1kg of vegetables), mix, leave to stand for about 30 minutes, mash so that the juice comes out and then pour everything into the jar. The juice should then be about as high as the vegetables in the jar, otherwise you should mash it again.

Wait and don't touch it

I have found minimum waiting times of 3 weeks to a month on the Internet. However, we have also left the jars for 3 years. The fermentation then continues slowly and the vegetables become a little more acidic, but we still liked the flavour! During this time, the jars should be stored in a dark and cool place. But we keep them in the cellar, and of course it's not that cool there in the southern Spanish summer. We try not to touch the jars. If we have to move them, we don't touch them by the lid, but by the body. If we would touch them by the lid, some oxygen could get into the jar.

Eat a little every day

There are many products on the market that are called "superfoods", are often quite expensive and are often of dubious health value. Lactofermented food is scientifically recognised as having many positive effects for most people - and it's almost free! However, it is sufficient to eat a small amount every day, and you should get used to it slowly at the beginning.

Our special experiences

Fermenting unripe avocados

In September 2022 we had guests on our finca. They discovered a lot of unripe avocados under the trees (fallen much earlier than at harvest time) and wanted to do something with them. So we cut them into pieces and fermented them. We waited almost 2 years, because maybe unripe avocados need a little longer to become edible? We have now opened the jar - and the formerly hard, unripe avocados are now soft and delicious! Murielle and I ate quite a bit, maybe 200g each, and we don't have any stomach ache and we feel good!

Fermenting bitter olives

A few years ago we picked olives from our trees and pickled them. Normally fresh olives are inedible because they are too bitter. But when they are dried, most varieties are fine to eat, and we really like some of them when we simply pick them up from under the trees while they are still dried. Another option is to put them in water for up to 4 weeks, and change the water as often as possible to wash out the bitter substances. We skipped this process and fermented the olives for a few months, some with vegetables, others without any other ingredients. After that, they tasted good and were no longer bitter.

Fermenting bitter beetroot

In Aug 2023, we harvested beetroot from our garden. It had been in the garden for a long time and didn't want to grow bigger, probably because of lack of water. Now it tasted too bitter for us. We found out on the internet that beetroot should always grow quickly so that it doesn't become bitter. What to do? We put them in jars for lactofermentation and hope that the fermentation process will transform the bitterness into something tasty. And yes, it worked! Some months later, we opened the first glass, and we liked it really! Two more glasses are still waiting in our cellar. 

Extern links

• Wikipedia about Lactofermentation