Onion storage methods and hot‑water blanching improve flavor

To keep green onions fresh and retain quality, they should be stored in a cool (0 °C–5 °C), dry and well‑ventilated place such as a cellar or pantry. Refrigeration is discouraged because low humidity can cause spoilage. Effective ventilation can be achieved with jute nets or wooden crates layered with dry paper or straw, which slows premature sprouting and preserves the bulbs.

A traditional Polish kitchen trick is to briefly blanch the onions in boiling water before using them in salads, herring, or spreads. The quick dip (a few seconds up to half a minute) softens the sharp bite while keeping the crunch, making the flavor milder and slightly sweeter. After blanching the onions are rinsed in cold water, drained thoroughly and dried to avoid excess moisture in the final dish.