I’ve been growing tender herbs like basil, parsley, dill, chervil, cilantro, and chives for the past 25 years, and it’s taken me nearly that amount of time to find the best way to preserve their flavor long after I have harvested the last sprigs. These are just some of the techniques I’ve tried with disappointing results: drying (the herbs lost all their flavor); freezing (they lost their texture and got freezer burn); freezing in water in ice cube trays (I was left with a soggy, limp, and unappetizing mess).
Luckily, along the way I discovered that the best way to preserve herbs is to freeze them in oil or butter. And there’s a good reason for this: Each herb’s distinctive taste and aroma come from aromatic oils in the leaves, so preserving them in fat protects their authentic flavors. Packed in flat, thin layers in heavy-duty zip-top bags, frozen herb butters and oils are easy to store. I put a half-cup or so in a bag, freeze it flat, and end up with a thin layer of frozen goodness, which can be broken off into pieces as needed.
I use herbs preserved in oil the same way I use fresh herbs. They are particularly good in soups, stews, and salad dressings, where their vivid flavors can transform an ordinary dish into a spectacular one.
Herb butters are even more versatile. I use them in sandwiches, pasta, seafood, meat, poultry, popcorn—anything that tastes good with butter and herbs will benefit. I even replace plain butter with herb butter when making cakes and cookies.
Spend just an hour whizzing up a few batches of herb oils and butter, and you’ll be rewarded all winter long with vibrant flavors and delicious meals. Not to mention fond memories of your summertime herb garden.
How to Preserve Fresh Herbs in Oil or Butter