Hazelnuts lend their delicious nutty flavor and crunchiness to sweet and savory dishes, but their dark brown-to-black skins have little to offer. The skin of the hazelnut is bitter, so you'll need to peel the nuts before using them in baking or cooking. Clean the hazelnuts carefully; then roast them to bring out their flavor and scent.
How to Blanch Hazelnuts
Boil the Water for Blanching
Blanching is simply boiling food for a short period of time to cook only the outermost layer. When you blanch hazelnuts, the skin loosens, but the entire nut isn't cooked. A boiled hazelnut would be soft and waterlogged and not at all pleasant to eat.
For every 1 cup of hazelnuts you want to blanch, you'll need 3 cups of water. Pour the water into a saucepan and set the pan on the stove to heat until the water boils. If you're blanching a large quantity of hazelnuts, blanch them in batches to avoid filling the pan more than halfway. Otherwise, when you add the nuts, the boiling water could overflow.
Add Baking Soda
Baking soda seems to improve the effects of blanching to remove hazelnut skins, though it isn't clear why. When the baking soda is added to boiling water, the water fizzes up with thousands of bubbles. It's possible that the tiny gas bubbles penetrate the hazelnut skin and help break it down.
On the other hand, baking soda's high alkalinity could be responsible for increasing the effectiveness of the blanching process. The alkaline in baking soda may soften and loosen the skins. When it's time to remove the skins, they slip off easily.
Whatever the reason, your hazelnuts will be easier to skin if you add baking soda to the water. When you see the water begin to boil, add 4 tablespoons of baking soda for 3 cups of water. The baking soda will quickly dissolve without any need for stirring.
Add the Hazelnuts
Carefully drop the hazelnuts into the boiling water directly after you add the baking soda. You don't want to miss out on the effects of the fizziness of the water. However, don't rush too much. You don't want to throw in the nuts and end up splashing yourself with boiling water.
The water will cool down a little after the addition of the cold nuts, but it will quickly boil up again. Turn down the heat if the water threatens to boil over. The hazelnut skins' color will leach into the water, turning it a dark reddish-brown or black, which is harmless.
Blanch Hazelnuts Briefly
Remember that the point of blanching hazelnuts is to cook only the outermost layer, so they must only boil for a short time. Boiling them for 3 to 4 minutes is usually plenty to get the job done. While the hazelnuts are blanching, half fill a large bowl with cold or iced water.
After 3 minutes, use a slotted spoon to lift out one hazelnut. Drop the nut into the cold water and wait a few seconds before lifting it out with your fingers. Squeeze the nut and try to remove its skin. If the skin comes away easily, it's time to remove all of the hazelnuts from the water.
If the skin on the nut is difficult to remove, wait another 30 seconds and then test a second nut in the same manner. After 4 minutes, the skins should slip off easily. Don't boil the hazelnuts longer than 4 minutes, or they'll become soggy.
Strain and Cool
One of the easiest and safest ways to strain the blanched hazelnuts is to use a colander. Stand a colander in your sink and tip in the saucepan's contents. When the hot water has drained away, lift the colander out of the sink. Pour the hot hazelnuts into the bowl of cold or iced water you prepared earlier.
Replace the colander in the sink. Wait 10 or 15 seconds, and then strain the hazelnuts again by pouring the bowl of water into the colander. Pick up the colander and shake off the excess water. Now the nuts are ready for peeling.
Peel the Hazelnuts
Peeling hazelnuts involves squeezing them until the inner nut pops out of its wet, brown overcoat. You must skin each nut one by one, which sounds time-consuming; right? However, the process should only take less than a second per nut.
If you have children who aren't allergic to nuts, this might be a good time to invite them to help you. However, check carefully that the nuts are cool and are not going to burn tender little fingertips. Also, check that not too many nuts disappear into young mouths, or you may not have enough for your recipe.
Place the skinned nuts on a clean, dry dish towel or kitchen paper, and put the skins to one side. Hazelnut skins are edible but not tasty. When you've finished, you can put the skins in the trash, or if you have a compost bin, throw them in it.
Roast the Hazelnuts
Roasting hazelnuts after blanching gives them a delectable, rich, nutty flavor and avoids the bland taste that boiling sometimes causes. To prepare for roasting, heat your oven to 375 degrees Fahrenheit.
Blot the peeled nuts dry with a dish towel or kitchen paper, and then spread them in a layer one nut deep on a baking tray. Put the baking tray in the oven and roast the nuts for 15 to 20 minutes. Check their color frequently and remove the hazelnuts from the oven as soon as they turn a light golden brown.
Prepare Your Skinned Hazelnuts
Wait until the roasted hazelnuts have cooled down before preparing them to add to your recipe. Place the hot baking tray on a wooden chopping board or another heatproof surface. After 20 to 30 minutes, the nuts should be cool to the touch.
If your recipe calls for chopped nuts, you can now chop the hazelnuts on a chopping board with a sturdy, sharp knife. But, before you begin, place the chopping board on a rimmed baking sheet. That way, when they inevitably bounce off the board, they'll land on the sheet and not the floor.
Chop the hazelnuts in small batches of five or 10 at a time. Place the knife over the nuts, and push down, rocking the knife across the group of nuts. After you pass over the nuts with the knife, scrape them together and cut them again until the nut pieces are as fine as you want.
Store Your Hazelnuts
Perhaps you're so organized that you're preparing blanched hazelnuts days or weeks before you plan to use them. To store chopped or whole hazelnuts, place them in a container that you can seal tightly with a lid and put them in your freezer. Blanched hazelnuts keep for three months in a freezer.