Here are the steps for making a quart/liter jar of fermented veggies. You don’t need precise measurements, just a decent amount of salt in water, and enough water to completely cover the veggies, so you can either follow this, or adjust to whatever quantity you want.
Green beans and cabbage are two good veggies to start, fermented green beans are crunchy and delicious, and shredded cabbage is basically becomes sauerkraut, but for starters, any hard vegetable is good.
1. Dissolve 2 tbsp salt in 1 quart/liter of water. Cut up veg into whatever shapes you like, or leave whole if already small enough, like green beans.
2. Place whole or cut up veg in container, fill with salt water (leave 1-2″ air space), weigh down so veg are completely submerged, cover with tight lid.
3. Let ferment at room temperature (60-70°F), out of direct light; every day, oven the lid for a second to let gases escape.
4. After 4-5 days, check for bubbles, cloudiness and a sour, vinegary aroma, and taste for flavor and texture. The longer it ferments, the tangier it gets. If there’s a nasty smell or anything funky growing on top, scrap it and start again (this will practically never happen unless you’ve let the veggies float to the top).
5. Refrigerate whenever it tastes good to you. This will slow the fermentation right down. Fermented veggies in the fridge should be good for months.