Homemade cocktails have entered a modern renaissance, and if you want to become a great at-home bartender, you've probably started off by purchasing high-quality liquor and a few essential tools. However, cocktail book author Kevin Liu says that if you don't use the right water, you may as well pour your drinks down the drain.

Using the right water is absolutely essential if you serve your cocktails over the rocks, blend in some ice cubes to create frozen drinks, or just add a little water to balance out flavors. To get the best water for your cocktails and avoid adding "off" flavors or other unwanted qualities, start by testing your tap water to see if it's up to snuff.

Liu writes on Serious Eats that the best-tasting water has dissolved minerals (solids) in it, and a TDS (total dissolved solids) level of around 35 milligrams per liter; the ideal mix of minerals consists of sodium, potassium, calcium, and magnesium. You can purchase a TDS water quality meter for as low as eight dollars from retailers like Amazon.

If you find out that your tap water isn't great, you can start with filtered water with no TDS whatsoever, and add a very small amount of baking soda, calcium chloride, and magnesium chloride. For the fastest last-minute solution, Liu says that Smart Water is the bottled water brand that lands closest to the ideal water composite.