Conservation avec du sel et bactéries lactiques
- Plonger les aliments dans de l’eau salée pour favoriser le développement des bactéries lactiques (lactobacilles) par macération.
- Privées de contact avec l’air, celles-ci vont proliférer en se nourrissant des sucres présents dans les aliments, qu’elles vont transformer en acide lactique.
- Celui-ci va quant à lui contribuer à détruire les bactéries pathogènes.
En bref, la lacto-fermentation est le procédé de transformation des sucres (le glucose présent dans les légumes) en acide lactique par les bactéries.
Au bout d’un certain temps, la teneur en acide lactique atteint un certain seuil : elle arrive à l’équilibre et la fermentation s’arrête. La conservation peut alors se prolonger plusieurs années, l’acide lactique ayant pour effet d’inhiber les autres micro-organismes responsables de la moisissure.
Après quoi, les légumes lactofermentés seront non seulement acidulés (un peu comme s’ils avaient marinés dans du vinaigre, à la manière de pickles) mais resteront croquants et seront plus intéressants d’un point de vue nutritif.
General Tips
Limit air space: A half-filled jar is guaranteed failure.
Don't open jars for 3-4 weeks: Keeping air out is essential to a good fermentation.
Don't eyeball it: Weigh everything in the beginning, follow recipes exactly to get a feel for how many vegetables can fit in a jar.
Ferment in the fall: Ones fermented in the fall will be more successful than in the summer. Winter veg stay firmer than summer veg.
Non-chlorinated water is ideal, because chlorine is antiseptic. Filter the water, or let it rest on the counter for a few hours to permit the chlorine to evaporate. Using chlorinated water doesn't mean the ferment will fail, but it can slow the process.
We've had luck with using water straight from our tank, but if you want to guarantee results it may be best to leave the water to stand for a while first. Also, check that your water supply doesn't contain chloramines, a stable form of chlorine (mix of ammonia and chlorine) that doesn't evaporate at ambient temperature, and that can't be boiled out. It's possible to filter out chloramines with a good filter (berkey filters do this).
Chlorinated water won't necessarily stop fermentation from happening, but it can make it sluggish.
Brine
When fermenting vegetables in brine, a basic ratio of salt for 1% salinity is of approximately 30 g per liter of water, or 10 g of salt per kg of total vegetable+water weight, is necessary for vegetables. Again, it's possible to add up to 5% for long term preservation. Allow the salt to fully dissolve in the brine before using. Refer to the table below for the amount of salt necessary per water.
will make them less bitter and they'll absorb the brine better. Eggplants don't keep as long as other veg; they'll get too acidic after 6 months.
Tomatoes. Like eggplants, tomatoes become more acidic with time and shouldn't be left to ferment too long. Process in 2% Brine (1 litre of water and 20 grams of salt). Delicious with basil, garlic, mustard seeds and chili flakes.
Garlic. Best to use up early summer garlic for the best flavor. Lacto-fermenting garlic in brine mellows the pungency of the garlic. It's possible to use fermented garlic for nearly all of the same applications as raw garlic in a recipe.
Zucchini. Pick end of season zucchini, they'll keep longer. It isn't necessary to peel the zucchini. It's possible to pick it in chunks, or shredded to make a relish.
Bell peppers. Pick end of season peppers, they'll keep longer. Early summer peppers will soften too much. Pickle in 5 % brine. Use peppers that appear hydrated, and that aren't damaged or wrinkled. Don't use peppers that are overly sanitized (triple-washed that come in bags), they may not pickle well.
Cucumbers. Pick end of season cucumbers. Use very fresh cucumbers if you want them to stay crisp. Cut off the little brown end where the flower of the plant grows, apparently it helps them stay firm. Pickle in 5 % brine.
Mushrooms. Preparation depends on the kind of mushroom. Fermentation does 'cook' them, but some have problem compounds that might cause gastro-intestinal issues. For some varieties it might be necessary to cook them at high heat (boil) first. Also, many varieties break down during fermentation and become 'mush'.
Recipes
To start doing lacto-fermentation, we recommend these great recipes:
kimchi recipe by Tout Cru! Fermentation.
Achard de carottes a l'indienne (French) by Marie-Claire Frédéric.
Lacto-fermented eggplant by Cultures for Health.
Fermentation (recipe book) by Rachel de Thample.
Remember, fermentation is just controlled decay: your most important ingredient is time.
Resources
Ni Cru Ni Cuit (French) by Marie-Claire Frédéric.
The Art of Fermentation by Sandor Katz.
The Messy World of Fermentation by Aaron Vansintjan for Low-Tech Magazine.