Water, sugar and lemon juice is placed in a pot and heated to 125 C. If you do not have a thermometer to measure - a drop of syrup, put in a bowl with cold water should become a solid ball that Foma keeps his once out of the water (the ball must be able to be flattened by hand and not be broken). Add the essence and syrup remove from fire. Egg white mix of snow, then it gradually add hot syrup, stirring continuously (with mixer). Add nuts if they are placed at this time, it is important to be warm. Tahan heated to 50 C (maybe in a microwave - 1 minute 800Vt). Mix sugar foam and Tahan and stir gently and carefully. Everything must be done quickly in order not to cool the mixture. The warm mixture is poured onto a greased and covered with baking paper baking dish or plastic box. After cooling at room temperature is sealed is placed in the refrigerator for at least 36 hours (during this time to form sugar crystals). Cuts are cold, with a sharp knife. Wrapped in household foil, halva can be stored for several weeks.