Choosing a Liquid
Water is the most commonly used liquid in soapmaking. You can make perfectly usable soap with tap water, but it is usually suggested that you use purified water. You can use water that has been filtered by an on-the-tap filter or a pour-through filter, which will remove some of the undesirable material from your water. Or you can purchase distilled, purified, and drinking water at the grocery store. Distilled is preferred by many soapmakers as it is as “pure” as you can get. Try a few different kinds to see which one you like. You may even find you don't notice a difference at all, so you can save some money using tap water.
Different Types of Water
Another type of water you could use is seawater, which adds natural salt and other minerals to your soap. Don't collect your seawater in a polluted area, or you'll be adding all kinds of things to your soaps that you don't want. Since seawater contains plant life, it is a good idea to use it right away because the microorganisms will die and decay and make the water unsuitable to use.
Through history, people have venerated wells by dedicating them to goddesses, saints, and other religious figures. Waters from some wells are thought to have healing properties. Regardless of whether or not the water you collect has healing properties, a pilgrimage to such a place is a memory to cherish. Make soap from the well water, perhaps leaving it unscented and uncolored to focus on the water itself, or add botanicals, sand, and even soil from the site as well. Be respectful, of course, and don't strip the area of flowers and stones.
Soapmaking can help you create a lasting souvenir of a vacation or pilgrimage. At the ocean, collect some water and some sand in an empty plastic drink bottle. You can make a one-pound soap batch using just six ounces of water. At the family cabin on the lake, collect some lake water and dry some plant matter from the lakeside.
If you live in an unpolluted area, you can use collected rainwater in soapmaking. Many soapers find that rainwater is soft and useful for soap-making. If you leave out containers to collect rainwater, tip them over during mosquito egg-laying season, or you will find yourself with a homegrown herd of buzzing biters.
Scented waters — such as those often used in cooking — make excellent liquids for soapmaking. Rosewater and orange flower water can be found in the Middle Eastern food sections of large groceries and at specialty food stores. They are used to flavor sweets in cooking, and they retain a certain amount of their fragrance in soapmaking.
Making Soap with Milk
Milk soaps have been used for years for their skin-softening properties. The combination of butterfat and lactic acid makes for a very skin-smoothing soap. There are some special requirements to using milk as your liquid. Follow some simple procedures, and you'll be very happy with your milk soaps.
Cow's milk makes excellent soap. Determine the butterfat percentage you want depending on the result you want. If you want the exfoliating properties of lactic acid without the moisturizing properties of butterfat, use nonfat milk. At the other extreme, use half-and-half or even cream for extremely creamy, rich soap. Other milk products that are popular with soapmakers are goat's milk, buttermilk, evaporated milk (not condensed milk!), powdered milk, and coconut milk (although it's not really “milk”).
Controlling the Temperature
The main thing about making soap with milk is that you must control the temperature of the milk-lye solution. The answer to the potential problem is simple: Freeze the milk! Weigh the amount of milk you want to use and place it in a freezer-safe container. The wider and shallower the container is, the faster it will freeze. When the milk is nearly solid, take it out of the freezer and stir. It is ready to use if it is firmly slushy.
Goat's milk soap is extremely popular for use in soapmaking. It may surprise you that keeping a small herd of goats for milk is not uncommon in rural areas. If you do this, or know someone who does, get some milk and make soap! You can, of course, also purchase goat's milk at the grocery.
Adding the Lye
Place the slushy milk in a large heatproof glass or stainless steel bowl. The bowl needs to be big enough to hold the milk when it thaws plus the volume of the lye. There should also be some headroom to contain sloshing.
With your goggles and gloves on, weigh the lye. Sprinkle the lye, little by little, onto the milk. Incorporate it as you go with a big whisk. Don't go too fast, or you'll build up too much heat in one area. Don't go too slowly, or the slush will melt before you get all the lye in. Stir constantly and carefully. The milk will turn pale to bright yellow depending on the kind of milk. If it gets curdled and brown, it has overheated. Although some soapers would just soldier on, you probably want to neutralize it with vinegar and rinse it down the drain. If you get a brown mess, it will smell hideous, so work quickly to take care of it and open up the windows!
If you've been careful with the additions and the temperatures, you will have a lovely yellow solution ready to add to the oils. Keep the temperature of the oils low, about 85° to 90°F, to avoid overheating the milk-lye solution.
