HARVESTING AND ID TIPS 

1. The ferns should still be tightly coiled, you do not want to pick or eat any that are totally unfurled.

2. Ostrich ferns will have a “u” shaped stem it will not be round/solid–ever

3. The ferns will have a brown papery covering on it when young, not white, which should be be removed before consuming. White coating on your ferns means you have a different species, typically something like Osmunda, or the interrupted fern–don’t eat or serve those to others as they can make you sick. 

SUSTAINABILITY 

Since they’re so popular, fiddleheads are commonly overharvested. If you harvest your own, and especially if you harvest from public land, know that it’s considered bad form to take every fern growing from a fiddlehead crown. Take a couple fiddles from a crown, and move along. Think of your harvesting as “thinning” the ferns from a plant, as opposed to clear-cutting, which some do. 

COOKING

DON’T EAT THEM RAW 

No matter what species of fiddlehead you have (as long as it’s one of the two I’ve mentioned) they need to be cooked and should not be eaten raw. Despite the claims of some people that they can eat them raw without an issue, most people can’t, and if you feed someone fiddleheads for the first time and they get sick, you’re likely to scare them away from fiddleheads, and potentially wild food in general. That being said, there’s definitely a sweet spot for cooking, as overcooked fiddleheads are mushy and unappealing

BLANCHING 

The tried and true method for cooking fiddleheads is blanching. Although you can cook fiddleheads by simply putting them in a pan, it’s not ideal as it’s easy to overcook them, have them soak up too much oil, or turn black in spots from uneven heat.

To blanch fiddleheads, put them in boiling, salted water for 1-2 minutes, then remove and allow to cool without putting them in an ice bath, which can cause them to discolor. Blanching locks in and preserves the green color, as well as par cooking them a bit so they don’t discolor and oxidize (turn brown) after cooking, which, while still being edible, is unappealing. After they’re blanched, fiddleheads can be added to all kinds of things: salads, soups and stews to name a few, but do make sure not to cook them too long as you want them to be a little crisp. Fiddleheads should not be mushy. 

PRESERVATION 

There’s a few different ways that you can preserve fiddleheads for use in the off-season, and some are better than others.

DRIED 

Fiddleheads, specifically bracken fern (known as gosari) are dehydrated, and are an integral part of the Korean dish Bibimbap, a sort of meal-in-a-bowl consisting of rice, eggs, various vegetables and condiments. To dry fiddleheads, I blanch them, and then dehydrate, which helps them keep their color.

Dehydrating is a traditional method of preservation popular in Korea with bracken ferns. 

Commercially dried bracken ferns are discolored as they’re dried from fresh, as opposed to being blanched. I suspect blanching also reduces some of the potentially problematic compounds found in bracken fern, but I’m speculating there. Either way, blanching fiddles before drying improves them. See more on drying and cooking with dried fiddleheads here. 

PICKLED 

Pickling works well with fiddleheads as it can keep them crunchy. That being said, in order for them to keep their tender-crisp texture, you’ll need to follow my recipe for crunchy pickled fiddleheads, as canning in a waterbath will make them soft. See a recipe for pickling fiddleheads here.

FREEZING (NOT RECOMMENDED) 

Some people claim to have success freezing fiddleheads, but just because it can be frozen, doesn’t mean it’s going to taste good after it’s thawed. Frozen fiddleheads develop a soft, mushy texture and I don’t reccomend them. Better to eat them en-masse when they’re perfect and in-season. Freeze drying is likely a great option, but I don’t have one yet. 

DON’T THROW THE STEMS OUT! 

Most people just want the curled crosier, or fiddle. But, as long as the fiddlehead is in a good stage for eating, the whole thing, long stem and all is edible, and you shouldn’t throw it away after you trim them. Chop up excess stem and add it to a veggie saute. 

Long stems are ok–everything is edible, except that brown papery fluff.

OVERCOOKING

This is the most common problem with cooking these I see. Some people really don’t like fiddleheads, and after having them prepared by someone else for me a few different times, I can understand why. Part of the problem is that people don’t understand how they should be cooked, it’s not their fault, fiddles are an obscure vegetable, and take skill to prepare well. Just like any other vegetable, they need to be cooked with care. When fiddle ferns are overcooked, they’re soggy, limp and disgusting. Sauteed for too long their heavy and oily. Cook your fiddles, but don’t murder them.

Sourced From: https://foragerchef.com/how-to-identify-and-cook-fiddlehead-ferns/