Separate the egg yolks and egg whites. Add the egg yolks to a mixer and whisk. Add in the lemon juice, whisk until the egg and lemon have fully been mixed. Pour the oil in slowly, small drops at a time, as the mixer is going. This should take about 8 to 9 minutes. Once the mayonnaise is at the perfect consistency, sprinkle in the salt. Store in a small sealed jar in the refrigerator for up to 3 to 4 days.