Hazelnuts: What They Are and How to Choose, Use, and Store Them

Hazelnuts are the edible nuts of the hazel tree, sold raw, roasted, blanched, ground, or as paste, and they work in both sweet and savory cooking. Choose them by smell and appearance, store them away from heat and air to slow rancidity, and match the form—whole, chopped, ground, or paste—to what you're making. The guidance below applies to everyday cooking and snacking; if you have a tree nut allergy, avoid hazelnuts entirely.

What hazelnuts are and the forms you'll find

Hazelnuts (also called filberts in some regions) have a hard shell and a thin, bitter skin around a pale, dense kernel. The skin is what makes raw hazelnuts taste slightly astringent; removing it is why many recipes call for blanched nuts.

Roasting is the single biggest flavor change: it deepens the nutty taste and loosens the skin so it rubs off. If a recipe says "toasted hazelnuts," it usually means roasted and then skinned.

How to choose good hazelnuts

Quality shows up in smell, look, and how the nuts have been handled. Use the same checks whether you buy packaged or from a bulk bin.

• Smell: Fresh hazelnuts smell mildly sweet and nutty. A sharp, paint-like, or crayon-like smell means the oils have gone rancid—walk away.
• Look: Kernels should be plump and pale golden to light brown. Avoid shriveled, dark, or patchy nuts.
• Feel: They should be firm, not soft or rubbery. Softness can signal age or moisture.
• Bulk bins: Check that the bin is clean, covered, and turned over regularly. Nuts sitting open to air and light go stale faster. If the bin smells stale, the nuts will too.
• Packaging: Sealed bags or vacuum packs protect against oxygen and moisture better than loosely closed containers. Check for a date and prefer the freshest available.
• Shells (if buying in shell): They should be clean and free of cracks, holes, or powder, which can indicate pests or mold.

A quick test: bite one. Fresh nuts are crisp and clean-tasting. A soft, bitter, or lingering stale taste is a reason to return or discard the batch.

How to use hazelnuts

Match the form to the job, and toast when you want more flavor.

To toast and skin hazelnuts:

1. Spread shelled nuts in a single layer on a dry baking sheet.
2. Bake at about 350°F (175°C) for 8–12 minutes, stirring once, until the skins crack and the nuts smell nutty. Watch closely—they burn fast.
3. Tip them onto a clean towel and rub while warm; most of the skin flakes off. Don't worry about every fleck.

Everyday uses:

• Snacking: Roasted, lightly salted, on their own or mixed into a nut blend.
• Baking: Ground or chopped into cookies, cakes, brownies, and quick breads; sliced for topping.
• Spreads: Blend ground or whole nuts into a paste for sandwiches or a chocolate-hazelnut style spread.
• Salads and vegetables: Chopped toasted nuts add crunch to green salads, roasted carrots, or green beans.
• Sauces and dressings: Ground nuts thicken and enrich sauces; a hazelnut oil or paste works in vinaigrettes.
• Coating: Finely ground nuts can replace part of the flour or breadcrumbs in coatings for fish or chicken.

A simple starting point: toast a batch, chop half and grind half, and keep both on hand for the week.

How to store hazelnuts

Hazelnuts are high in oil, so the main enemy is rancidity, driven by heat, light, and air. The more the nut is broken down (ground, paste), the faster it goes off.

• Short term (a few weeks): Airtight container in a cool, dark, dry cupboard.
• Longer term (a few months): Airtight container in the refrigerator. Let it come to room temperature before using so they don't absorb moisture.
• Longest term (up to about a year): Freezer in a sealed bag or container, squeezed of air. Thaw in the container to avoid condensation.
• In shell: Keeps longer than shelled; still store cool and dry.
• Ground and paste: Refrigerate or freeze; use sooner than whole nuts.

Label with the date so you can rotate stock.

Common problems and when to discard

• Rancid: Sharp, stale, or paint-like smell and a bitter aftertaste. Discard—rancidity doesn't cook out.
• Mold: Visible fuzz, dark patches, or a musty smell. Discard the whole batch; don't just cut off the affected part.
• Soft or rubbery: Usually age or moisture; if there's any off smell, discard.
• Live pests or fine powder in shells: Discard and check the rest of your storage.
• Burnt after toasting: Bitter and acrid; small amounts can be picked out, but a scorched batch is best replaced.

When in doubt, trust your nose. A clean, nutty smell is the best single sign that hazelnuts are still good.