Welcome to the forum and the addiction! That
is odd. Metric volume, metric weight, and english weight all in the same recipe? How did they come up with that one?!?
This is what I can tell you about it.
It would definitely be easier and give you less chance of making a mistake to convert the amounts all to the same units. Like soapbuddy said, weight units are best to use, as they are more accurate and consistent. Thus, in your case, you need to convert your ingredients to either English unit ounces (by weight, not fluid ounces), or Metric unit grams. Whether you choose oz. or g. is your preference.
Because different substances have different densities, and therefore different volume-to-weight conversions, you need to find the specific conversion rate for each of your ingredients
when converting from volume to weight or vice versa.. This is especially true in CP soap making where accuracy is very important (to avoid a lye-heavy batch). If you are converting from weight to weight (for example, from oz. to grams), one conversion rate fits all, and you just need to use a little math.
For example, for a volume to weight conversion, 1 liter of
water (volume measurement) = 1000 grams of
water (weight measurement).
But 1 liter of
sunflower oil (volume measurement) = 928 grams of
sunflower oil (weight measurement).
This is because different substances have different densities. Therefore, it is important when you are converting to be using the correct conversion rate for your specific substance.
However, for weight to weight conversions, the conversion rate is the same for all substances.
1 ounce of water = 28.35 grams of lye
1 ounce of sunflower oil = 28.35 grams of lye
1 ounce of goats milk = 28.35 grams of lye
1 ounce of lye = 28.35 grams of lye
And so on and so forth. This is one reason using weight measurements is better than volume measurements.
This website is helpful. It has a conversion calculator for many different substances, including several common soapmaking oils. This will give you accurate conversions that use the correct conversion rate. It does not have lye, however. But since in your given recipe, lye is listed by weight, it will be easy to convert it from weight to weight, and thus you do not need a specific conversion ratio.
http://convert-to.comGoats milk
http://convert-to.com/742/goats-milk-va ... facts.htmlSunflower oil
http://convert-to.com/550/sunflower-oil ... facts.htmlHoney
http://convert-to.com/246/honey-amounts-converter.htmlIf we do all the conversions, your given recipe by weight converts to:
Ounces31.04 oz. of goats milk
78.56 oz. of sunflower oil
12.35 oz. of lye
2 oz. of honey
Grams880 g. of goats milk
2227 g. of sunflower oil
350 g. of lye
57 g. of honey
Lye calculators are used to calculate how much lye you need to add to your oils in your recipe. Again, because different oils have different densities, the rate that determines the amount of lye needed to saponify the amount of a given oil is different for each oil. Lye calculators are used to formulate or reformulate your own recipes.
Most soapmaking books should have consistent units of measurement in their recipes. Bramble Berry has some good recipes on their Teach Soap page as well.
http://teachsoap.comI hope this helps and doesn't confuse you more. Weight and volume always did confuse me!
Good luck, don't give up, and have fun!!!