Dissolve salt fully in filtered water, preferably while boiling the water. Let the water cool completely to room temperature. This is very important!
Divide veggies, garlic, dill, and horseradish evenly between 2 half-gallon jars. Pack them snugly.
Pour brine at room temperature to cover, leaving 2–3 cm headspace.
Weigh down veggies with a folded cabbage leaf and a clean glass weight. It is very important to make sure there is no organic matter (pieces of vegetables, dill, garlic....) that is exposed to air. All vegetables, dill, garlic, horseradish has to be completely submerged in the brine. The glass weight has to be submerged too.
Cover with lids (loose if solid) or airlocks to let escape the air bubbles that form during fermentation process.
Ferment at room temp for 5–7 days, tasting after day 4. Warmer kitchens go faster.
Once flavor is pleasantly tangy, cover tight with lids and move to fridge.