Write an article based on this summary:

Melt the butter. Set up a double boiler Whisk egg yolks and lemon juice together. Watch for signs of separating. Add the butter gradually. Adjust the spices and liquids. Keep in a warm place.
Heat the butter in a wide pan, until there are just a couple small pieces of butter left. Remove from heat so it cools while you move on to the next step. If you're feeling extra fancy, clarify the butter by skimming off some or all of the milk solids. Their removal will make the sauce thicker, but less rich. Alternatively, just let these sink to the bottom of the pan, and decide what to do with them when it comes time to pour. . If you don't have a double boiler, just fill a pan about a ⅓ full of water and heat until you see a couple thin streams of bubbles. Place a heat-safe metal or glass bowl snugly on top of the pan, without touching the water. This indirect heat reduces the risk of your sauce burning and separating. Add four egg yolks and 1 tbsp (15mL) lemon juice to the double boiler. Whisk constantly and vigorously until the mixture becomes frothy and lighter in color, and the whisk leaves trails in the mixture.  An experienced chef can achieve this in a minute or two, but 5–10 minutes is common for a first try.  Scrape down the sides of the bowl occasionally as well. Any egg left sitting in place might scramble. If the egg mixture gets too hot, it will curdle or "split" into solids and liquid. If it starts to feel too hot or steams heavily, pick up the bowl with an oven mitt or towel. Whisk vigorously for 30 seconds to cool the eggs down, then return to heat.   The first few times you make hollandaise, it can be difficult to identify the right temperature. To play it safe, do this for a few seconds, once a minute. If the mixture starts to curdle, immediately scrape it into another bowl and whisk rapidly with 1 tbsp (15mL) ice water. Pour the butter in a small, steady stream, whisking constantly and vigorously. The sauce should thicken easily at first, then become more difficult to combine. Pour more slowly as this happens, since too much butter can cause the sauce to split. This step can take anywhere from 2–5 minutes. Once you're more experienced, you can add the butter ladle by ladle, or even in two large batches. This risks splitting the sauce, but if you succeed you'll have a faster, airier hollandaise. Stir in salt and cayenne pepper to taste. You may also whisk in a little more lemon juice if you want a tangier flavor. If the sauce is thicker than you prefer, whisk in a little hot water. Until you finish the other ingredients, cover the bowl and place in a warm spot. Cool temperatures may split the sauce. If the sauce gets too thick, whisk in a few drops of warm water before serving.