Common Hazel (Common Hazelnut, Forest Nut)

Common Hazel (Common Hazelnut, Forest Nut)
Corylus avellana L.
Birch Family (Hazel Family) — Betulaceae (Corylaceae)

Description of Hazel (Hazelnut)

Common hazel is a multi-stemmed shrub 2–7 m tall, rarely a tree up to 10 m. Branches light gray, young ones with yellowish hairs and glands, adults bare. Leaves alternate, short-petioled, round or obovate, 5–12 cm long, 4–10 cm wide, with unequal cordate base, shortly pointed, doubly toothed on edge, dark green above, lighter below, pubescent along veins; petioles glandular, stipules hairy, falling early. Flowers unisexual, appear before leaves: staminate in catkins (3–8 cm), pistillate in bud-like spikes with crimson stigmas. Fruit one-seeded nut, 1–2 cm, in bell-shaped involucre, brown, woody, clustered 2–5; shell hard, with longitudinal stripes and velvety pubescence at top. Flowering in March–April, fruiting in August–September. Lives 80–100 years. Propagated by seeds, shoots, layers. Varieties: ‘Barcelona’, ‘Cosford’, ‘Trapezund’. Other species: C. maxima (large-fruited), C. heterophylla (variable-leaved), C. colurna (bear hazel).

 

Distribution and Ecology of Hazel (Hazelnut)

Common hazel distributed in European part of Russia (except Far North and southeast), Caucasus, Asia Minor, Western Europe. Grows in understory of mixed and deciduous forests, edges, clearings, burns, up to 2000 m altitude. Prefers fertile, moist soils (pH 5.5–7.0), shade-tolerant, withstands frosts to -30 °C. Cultivated in gardens and plantations. Propagated by seeds (sow in autumn, stratification 4–5 months) or vegetatively (layers, shoots). Yield: 0.5–2 kg nuts per bush. Care: watering (10–15 L/bush every 7–10 days), organic feeding (5–10 kg/bush), pruning, protection from nut weevil and longhorn beetle. Ecologically enriches soil with nitrogen, but intensive fruiting depletes ground. Pollen may cause allergy.

 

Raw Materials from Hazel (Hazelnut)

Raw materials: bark (cortex Coryli avellanae), leaves (folia Coryli avellanae), fruits (nux Coryli avellanae), nut oil. Bark harvested in spring (March–April) or autumn (August–October), dried at 25–30 °C (yield 30–35%). Leaves harvested in May–June, dried in shade at 20–25 °C (yield 20–25%). Nuts harvested in August–September, dried at 30–35 °C (yield 80–85%). Oil extracted by cold pressing (yield 50–60%). Quality: bark gray-brown, mold-free; leaves green, moisture <12%; nuts without bitterness; oil clear, yellowish. Store bark and leaves in bags (2–3 years), nuts in dry containers (1–2 years), oil in dark bottles (1 year). Dry distillation of wood yields “Forest” liquid for eczema treatment. Nuts aroma sweetish, oil nutty.

 

Chemical Composition of Hazel (Hazelnut)

Bark: essential oil (0.1%), tannins (10%), betulin, phlobaphenes, lignoceryl alcohol. Leaves: essential oil (0.04%), flavonoids, myricitroside, ascorbic acid (150–200 mg/%), carotene, tannins (10%), palmitic acid, alkaloids, sucrose. Nuts: fatty oil (60–75%, linoleic, oleic acids), proteins (15–20%), carbohydrates (10%), vitamins (E, B1 up to 9 mg/%, biotin), minerals (iron, potassium, magnesium). Pollen: proteins, vitamins (B, C). Calorie content of nuts: 650–700 kcal/100 g.

 

Effects and Applications of Hazel (Hazelnut)

Tannins in bark and leaves have astringent, anti-inflammatory, diuretic effects. Preparations used for hypertension, atherosclerosis, anemia, diabetes, urolithiasis and cholelithiasis, varicose veins, periphlebitis, trophic ulcers, prostatitis, rheumatism, neuroses, liver diseases. Leaf infusions stimulate appetite, help with hemoptysis, bronchitis, fever. Bark decoction effective for malaria, diarrhea (from involucre). Nuts strengthen body, improve lipid metabolism, support lactation, used for exhaustion, flatulence. Oil rubbed for hair strengthening, burns (with egg white). Pollen with honey as tonic, with St. John's wort decoction for enuresis.

 

Precautions for Using Hazel (Hazelnut)

Leaf or bark infusions (>100 ml/day) may cause diarrhea or allergic reactions due to tannins. Nuts in large quantities (>50 g/day) may disrupt digestion. Oil requires dilution (1:1 with base oil) for sensitive skin. Pollen may trigger allergy (anaphylaxis risk). Prolonged use (more than 1 month) may raise blood pressure due to vasoconstrictive effect. Store raw materials at humidity <12% to prevent mold. Give children under 3 years infusions in doses ≤10 ml/day. Do not combine with antihypertensives without doctor's consultation.

 

Contraindications for Using Hazel (Hazelnut)

Hazel contraindicated in allergies to nuts or pollen, peptic ulcer, gastritis, pancreatitis, hypotension, pregnancy (allergy risk), children under 1 year. External oil use prohibited in eczema, psoriasis, open wounds. Do not combine with anticoagulants or diuretics without doctor's consultation.

 

Recipes with Hazel (Hazelnut)

1. Leaf Infusion for Prostatitis. Pour 10 g leaves with 250 ml boiling water, infuse 2 h, drink 50 ml 3 times a day, 10 days.
   
2. Bark Decoction for Varicose Veins. Boil 15 g bark in 500 ml water 10 min, drink 100 ml 3 times a day, 14 days.
   
3. Nuts for Anemia. Mix 30 g nuts with 10 g honey, eat 1 time a day, 21 days.
   
4. Oil for Burns. Mix 10 ml oil with 1 egg white, apply to skin for 15 min, rinse, 5 days.
   

 

Cosmetics from Hazel (Hazelnut)

Hazel oil and leaves used in cosmetology due to vitamin E and tannins, strengthening skin and hair.

1. Face Mask. Mix 10 ml hazel oil with 5 g honey, apply to face for 15 min, rinse. Use 1 time a week.
   
2. Hair Rinse. Infuse 15 g leaves in 500 ml boiling water 1 h, rinse hair after washing, 2 times a week.
   
3. Body Scrub. Mix 10 g ground nuts with 20 g sea salt and 10 ml oil, massage skin 5 min, rinse. Use 1 time a week.
   
4. Skin Oil. Rub 10 ml oil into hand skin before bed, 2 weeks.
   

 

Culinary Uses of Hazel (Hazelnut)

Hazel nuts used fresh, dried, roasted, in confectionery, dietary nutrition. Calorie content (650–700 kcal/100 g) exceeds bread, milk, raisins. Oil, resembling almond, used in culinary and cosmetology. Nuts added to cakes, candies, halva, creams, baking, coffee made from ground dry fruits.

1. Nut Milk. Soak 100 g nuts overnight, grind, pour 300 ml water, boil 5 min, strain, add salt and sugar to taste.
   
2. Salad with Nuts. 50 g nuts, 100 g salad leaves, 50 g cheese, 10 ml hazel oil, mix, season with salt.
   
3. Nut Dessert. Mix 100 g roasted nuts with 50 g honey, serve with yogurt.
   
4. Whipped Cream with Nuts. Grind 50 g roasted nuts, sprinkle on whipped cream (200 ml) with 50 g sugar.
   

Tips: Roast nuts 5–7 min at 150 °C to enhance aroma. Store nuts at 0–10 °C in airtight container up to 1 year.

 

Other Properties of Hazel (Hazelnut)

Hazel used in landscaping, soil stabilization on slopes. Wood for crafts, charcoal. Pollen attracts bees, but may cause allergy.