Food Safety Facts

By Food Safety Specialist Jason Bolton, Ph.D., Professor Emeritus of Food Science Alfred Bushway Ph.D., Extension Professional David Fuller, Food Science Specialist Beth Calder, Ph.D., Kathy Savoie, MS, RD, Extension Educator, and Kate McCarty, Food Preservation Community Education Assistant, University of Maine Cooperative Extension.

Originally developed by Extension Professor Mahmoud El-Begearmi, University of Maine Cooperative Extension.

For information about UMaine Extension programs and resources, visit extension.umaine.edu.

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Table of Contents

Fiddleheads, an early spring delicacy throughout the Northeast and Canadian Maritime Provinces, are the young coiled fronds of the ostrich fern (Matteuccia struthiopteris). Nearly all ferns have fiddleheads, but not all fiddleheads are edible. The Ostrich fern fiddleheads are edible, and can be identified by the brown, papery scale-like covering on the uncoiled fern. Fiddleheads are approximately 1 inch in diameter, have a smooth fern stem (not fuzzy), and also a deep “U”-shaped groove on the inside of the fern stem. Look for ostrich ferns emerging in clusters of about three to twelve fiddleheads per plant on the banks of rivers, streams, brooks, and in the woods in late April, May, and early June depending on your location. Make sure that you obtain landowner permission before harvesting fiddleheads.

Potential Foodborne Illness

A large foodborne illness outbreak occurred in 1994 which the Centers for Disease Control & Prevention (CDC) determined was the result of consumers eating raw or undercooked fiddleheads. Since then, several reported cases of foodborne illness have occurred associated with fiddlehead consumption. Researchers have yet to determine what the origin of the illnesses are from, but they do know that proper handling and cooking helps reduce the risk of foodborne illness related to the consumption of fiddleheads. Under no conditions should fiddleheads be consumed raw or under-cooked.

Symptoms of Illness from Eating Improperly Cooked Fiddleheads

Health Canada and the CDC have investigated a number of foodborne illness outbreaks associated with the consumption of raw or lightly cooked fiddleheads. The described symptoms of this foodborne illness were diarrhea, nausea, vomiting, abdominal cramps, and headaches. These symptoms generally occur within 30 minutes to 12 hours after eating raw or undercooked fiddleheads. These symptoms typically last less than 24 hours, but some cases could last up to three days.

If you experience symptoms after eating fiddleheads, you should seek the advice of a health care professional and contact your local public health unit to report this illness.

Harvesting Fiddleheads

Harvest the tender ostrich ferns as soon as they are an inch or two above the ground. Carefully brush off and remove the papery brown scales. Before harvesting in the wild, make sure that you can properly differentiate the ostrich fern fiddleheads from other fern fiddleheads. Not all ferns are edible; in fact, bracken ferns are carcinogenic and should not be consumed. (See Bulletin #2540, Ostrich Fern Fiddleheads for more information.)

Identifying and Harvesting Fiddleheads (YouTube video)

Cleaning Fiddleheads

Fiddleheads can be cleaned by first placing them in a colander and thoroughly rinsing/spraying the fiddleheads with clean, cold potable water. Submerging the rinsed fiddleheads in a bowl of clean, cool potable water should follow rinsing to remove the remainder of the brown papery coverings, and repeat as needed. Fiddleheads should appear clean after several rounds or rinsing and soaking steps.

Short-term Storage

Remember to keep fiddleheads refrigerated until you are ready to cook or preserve them. They can be stored in the refrigerator, but should be consumed or preserved within a week or less for best quality.

Cooking Fiddleheads

Clean fiddleheads can be safely cooked using two different methods, boiling and steaming. Sautéing, stir-frying or microwaving ostrich fern fiddleheads are NOT recommended methods. Fiddleheads should be boiled or steamed prior to use in other recipes that call for sauteing, stir-frying or baking.

Boiling

Bring lightly salted water in a saucepan or stock pot to a rolling boil and add clean fiddleheads that are cleaned according to the steps above. The water should fully cover the fiddleheads when added. Bring the water back to a steady boil and boil for 15 minutes. Based on research conducted at the University of Maine, we do not recommend packing fiddleheads tightly into the saucepan/pot or steamer during the cooking process. We recommend cooking in small batches to allow enough water or steam to thoroughly cook the fiddleheads

Steaming

Bring a small amount of water to a boil preferably under a stainless-steel, vegetable steamer in a saucepan. Add clean fiddleheads, cleaned according to the steps above, and steam for 10-12 minutes with a lid covering the steamer and saucepan.

After boiling or steaming, serve at once with optional toppings or seasonings, such as melted butter, vinegar, olive oil, salt or pepper. Cooked and rapidly chilled fiddleheads can be also served as a salad with an onion and vinegar dressing.

Fiddlehead Preservation (Freezing)

Due to the short season, some people like to preserve fiddleheads for later use. Freezing is the most common and easiest way to preserve fiddleheads. To freeze fiddleheads, make sure to follow these steps:

Clean fiddleheads according to the steps above. Blanch small batches of fiddleheads at a time by adding clean fiddleheads to potable water and boil for 2 minutes. The blanch time starts when the water comes to a rolling boil with the fiddleheads added. If the fiddleheads are packed too tightly, they won’t cook properly, so ensure there is enough water that the fiddleheads can move freely in the water during boiling. Immediately cool for 2 minutes in an ice bath immediately after blanching. An ice bath is made up of half ice and half water. Allow fiddleheads to drip dry in a colander or spin dry in a salad spinner, then place fiddleheads into moisture and vapor-proof, freezer-grade containers or re-sealable plastic freezer bags. Do not over fill bags or containers. Label, date and place containers or bags in the freezer. To use frozen fiddleheads, thaw in the refrigerator or submerge the containers or bags in cold water until thawed, and then cook the fiddleheads using one of the methods above. Frozen fiddleheads can be immediately cooked without thawing, but when using the boil method, the water will take longer to return to a boil during cooking.

Canning Tips and Recipes

UMaine Cooperative Extension does not recommend pressure canning as a method to preserve fiddleheads because process times have not been established and tested for home food preservation.

Commercial cider or white vinegar should be used and must have at least 5% acidity.

As guidance, approximately 3 pounds of raw fiddleheads should yield about 6 pints of pickled fiddleheads.

The brine should cover all the fiddleheads in the jar, while leaving a 1/2-inch headspace to ensure a proper seal.

Be sure to use best canning practices during the water bath process, which includes covering all jars in the canner with at least 1 inch of water and timing the boiling process when the water reaches a rolling boil (212 deg F) with all the jars in the canner.

Check for a proper seal on the jars after processed jars have cooled. If the tops are not depressed or have “popped”, place these jars immediately in the refrigerator and eat the fiddleheads within 1 month.

If you are new to canning, the National Center for Home Food Preservation offers helpful canning tips and tested recipes. General Canning Information offers information on how to properly select and prepare jars and lids for canning. UMaine Cooperative Extension also offers preservation workshops and resources.

Fiddlehead Recipes

The School of Food and Agriculture at the University of Maine and Cooperative Extension staff have tested these fiddlehead recipes below. The most successful of these recipes in terms of flavor, keeping quality, and safety are included in this fact sheet.

Plain Pickled Fiddleheads

Cider or white vinegar (5% acidity)

Sugar

1/8teaspoon each of black pepper, ground nutmeg, cinnamon, allspice and celery seed

(salt is also optional)

Clean and wash fiddleheads thoroughly using the process above. Pour enough vinegar over the fiddleheads to cover; then strain the vinegar off into a pan and measure the volume. Add 1 cup sugar for every gallon of measured vinegar. Add a large pinch of each of the spices and celery seed. Boil this syrup for 7-8 minutes, then immediately pour the hot liquid over the fiddleheads that are packed into clean pint jars. Remove air bubbles, adjust the liquid to 1/2-inch headspace and wipe the jar rim. Apply two-piece dome lids and adjust lids to fingertip tight. Process for 15 minutes in a boiling water bath canner, ensuring a rolling boil for the full 15 minutes and at least 1-inch of water is covering all jars in the water bath.

Makes approximately 6 pints if using 3 pounds of raw, cleaned and trimmed fiddleheads.

Sweet Pickled Fiddleheads

1 quart cider or white vinegar (5% acidity)

5 cups sugar

2 teaspoons canning & pickling salt

Clean and wash fiddleheads thoroughly using the process above. Mix vinegar, sugar and salt in a saucepan, bring to a boil and immediately pour over fiddleheads that are packed into clean pint jars. Remove air bubbles, adjust the liquid to 1/2-inch headspace and wipe the jar rim. Apply two-piece dome lids and adjust lids to fingertip tight. Process for 15 minutes in a boiling water bath canner, ensuring a rolling boil for the full 15 minutes and at least 1-inch of water is covering all jars in the water bath.

Makes approximately 6 pints if using 3 pounds of raw, cleaned and trimmed fiddleheads.

Quick Sour Pickled Fiddleheads

3 pounds raw, cleaned and trimmed fiddleheads

1/2-gallon cider or white vinegar (5% acidity)

2 cups water

1/2 cup pickling & canning salt

1/2 cup sugar

1/2 cup mustard seed

Clean and wash fiddleheads thoroughly using the process above. Mix brine ingredients and bring to a boil. Pour immediately over fiddleheads that are packed into clean, pint jars. Remove air bubbles, adjust the liquid to 1/2-inch headspace and wipe the jar rim. Apply two-piece dome lids and adjust lids to fingertip tight. Process for 15 minutes in a boiling water bath canner, ensuring a rolling boil for the full 15 minutes and at least 1-inch of water is covering all jars in the water bath.

Makes approximately 6 pints.

Garlic Dill Pickled Fiddleheads

3 pounds raw, cleaned and trimmed fiddleheads

8 cups cider or white vinegar (5% acidity)

1/2 cup canning & pickling salt

1 tsp dill seed per jar

1 garlic clove, peeled per jar

1 tsp of red pepper flakes per jar (optional)

Clean and wash fiddleheads thoroughly using the process above. Add dill, garlic and optional red pepper to clean, pint canning jars. Pack fiddleheads into jars. Mix vinegar and salt in a saucepan, bring to a boil, and immediately pour over fiddleheads. Remove air bubbles, adjust the liquid to 1/2-inch headspace and wipe the jar rim. Apply two-piece dome lids and adjust lids to fingertip tight. Process for 15 minutes in a boiling water bath canner, ensuring a rolling boil for the full 15 minutes and at least 1-inch of water is covering all jars in the water bath.

Makes approximately 7 pints.

Bread and Butter Pickled Fiddleheads

4 pounds raw, cleaned and trimmed fiddleheads

3 large onions, thinly sliced

1/2 cup pickling & canning salt

Cold water

Ice cubes

5 cups sugar

5 cups cider or white vinegar (5% acidity)

1 ½ teaspoons turmeric

1 ½ teaspoons celery seeds

1 ½ teaspoons mustard seeds

Clean and wash fiddleheads using the process above. In a clean 8-quart enamel, stainless steel or glass container, stir fiddleheads, onions, salt and enough cold water to cover fiddleheads until the salt dissolves and stir in ice to cover fiddleheads. Cover the container and let stand in a cool place for 2 hours or less. Drain fiddleheads, rinse with cold running water, and then drain thoroughly. Measure sugar, vinegar, turmeric, celery seeds and mustard seeds into a 8-quart heavy saucepan. Over high heat, bring to a boil. Add fiddleheads and onions to the saucepan and then heat to a boil. Spoon hot fiddleheads into clean jars and immediately ladle syrup over fiddleheads. Remove air bubbles, adjust the liquid to 1/2-inch headspace and wipe the jar rim. Apply two-piece dome lids and adjust lids to fingertip tight. Process for 15 minutes in a boiling water bath canner, ensuring a rolling boil for the full 15 minutes and at least 1-inch of water is covering all jars in the water bath.

Makes approximately 6 pints.

Cooked Fiddlehead Recipes

Shrimp and Fiddlehead Medley

1 pound fresh fiddleheads

6 ounces linguine, uncooked

6 cups water

1 ¾ pounds Maine shrimp, fresh or frozen

1 teaspoon olive oil

2/3 cup onion, chopped

1/2 cup green pepper, diced

1/2 pound fresh mushrooms, sliced

1 teaspoon thyme

1/4 teaspoon pepper

1/8 teaspoon salt

1/8 teaspoon celery seed

2 tablespoons lemon juice

Clean and wash fiddleheads using the process above. Bring water to a boil in a large saucepan, add shrimp and cook 3-5 minutes, or until slightly opaque white in color (frozen shrimp may take longer). Drain well, and set aside. Cook fiddleheads in boiling water (enough water to cover all fiddleheads during cooking) for 15 minutes. Drain. Meanwhile, cook pasta as directed, without salt or oil. Drain well, set aside and keep warm.

Add olive oil to a large, nonstick skillet and heat on medium high. Add onion and green pepper and sauté until crisp-tender. Stir in fiddleheads. Add sliced mushrooms, thyme, pepper, salt and celery seeds to vegetable mixture; stir well. Cook, uncovered, over medium heat 3-4 minutes or until mushrooms are tender, stirring often. Stir in shrimp and lemon juice; cook until heated through, stirring often.

Place pasta on a large platter. Spoon shrimp and fiddlehead mixture on top. Serve immediately.

Serves 6.

Fiddlehead Dijon

1 ½ pounds fresh fiddleheads

1 tablespoon cornstarch

1 cup nonfat buttermilk

2 teaspoons Dijon mustard

3/4 teaspoon lemon juice

1/2 teaspoon dried tarragon

1/4 teaspoon pepper

Clean and wash fiddleheads using the process above. Place fiddleheads in a vegetable steamer over boiling water. Cover and steam 12 minutes or until tender, but still crisp. Set aside, and keep warm.

Combine cornstarch and buttermilk in a small saucepan, stir well. Cook over medium heat until thickened and bubbly, stirring constantly. Remove from heat; stir in mustard, lemon juice, tarragon and pepper.

Arrange fiddleheads on a serving platter. Spoon sauce over fiddleheads. Serve immediately.

Makes 6 servings.

Fiddlehead Nutrition

Based on previous research, fiddleheads contain fiber, vitamin C, vitamin A, and omega-3 fatty acids (Bushway 1982; Delong, 2011).

Sources:

DeLong J, Hodges DM, Prange R, Forney C, Toivenon P, Bishop MC, Elliot M, Jordan M. The unique fatty acid and antioxidant composition of ostrich fern (Matteuccia struthiopteris) fiddleheads. Can J Plant Sci 91(5): 919-930.

Bushway AA, Wilson AM, McGann DF, Bushway, RJ. 1982. The Nutrient Composition of Fresh Fiddlehead Greens. J of Food Sci 47(2):666-7.

Publication recommendations based on “Fiddlehead Safety Tips”, Government of Canada: https://www.canada.ca/en/health-canada/services/food-safety-fruits-vegetables/fiddlehead-safety-tips.html.

Acknowledgements: Many thanks to Pat Pierson, Extension Educator, Waldo County; Evelyn Boynton, Hartland, Maine; and Al Bushway, UMaine Professor Emeritus of Food Science, for their valuable contributions in testing these recipes.

For more information, see Bulletin #2540, Ostrich Fern Fiddleheads, or contact your University of Maine Cooperative Extension county office.

Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

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