How we tested
Fresh herbs can be pricey, and supermarkets usually sell them in bigger bunches than you need for one recipe. So we were enticed by herb keepers that promise to keep them fresh longer. These devices are tall, covered canisters that hold herbs upright while their stems sit in a small amount of water. We chose five (priced from $8 to $30), filling each with equal amounts of chives, rosemary, and cilantro before placing them in the refrigerator along with another set of the herbs stored using the test kitchen’s usual method: loosely wrapped in a damp paper towel and set inside a zipper-lock bag. Two advantages of the clear, hard shells stood out right away: They protect leaves from being crushed by other items in the fridge and they let you see what’s inside. We checked the herbs’ condition every day, removing some from each keeper every few days to replicate typical usage and changing the water weekly according to instructions. Since not all the herbs in a bunch spoil at the same rate, we also picked through, removing the few that had turned. Once the majority of the bunch became unusable, the experiment was over.
All the herb keepers did help keep herbs fresh a little longer: Compared with the results of our standard method, the keepers added two to four days of freshness, with chives and cilantro seeing the biggest improvement in longevity. The three herbs spoiled at similar rates inside the keepers, with chives starting to discolor after a week and becoming unusable after 12 days; rosemary lasted about 15 days; and cilantro (surprisingly) a full month.
The big difference among herb keepers? Ease of use. We found some to be simple and well designed, while others were fussy and irritating. Shape was important; those with broader bases didn’t tip and spill water even when stored on the slim shelf on the refrigerator door. While all keepers could hold our bunches of herbs, those with larger capacities and wider tops avoided cramping and crushing them, and we appreciated taller keepers that didn’t make us trim down the stems. We preferred keepers that twisted to open; a few had to be pulled apart, which took more effort and sometimes sent herbs flying. The best keepers held herbs in place, instead of letting them flop out onto the counter when we opened them; these were easiest to load and use. Our favorite model had a deep, stable bottom half shaped like a water glass and a screw-on top that was simple to open and close. It kept herbs fresh and ready for use.