Weighing Powdered Milk Replacer Ingredients - How it is Different from 'Parts'
I am used to working with parts when I make formula.
Most of us are. Most of us were trained to think in terms of parts when constructing a recipe. You may think of a recipe, for example, as 1 part of Fox Valley 32/40 and 2 parts of water. Or, perhaps another recipe as 1 part Esbilac®, 2 parts of water and 1/4 part of heavy whipping cream. Do we need to start thinking about that differently?
Not at all. It is far more intuitive and easy to think about recipes in 'parts', whether those 'parts' are a tablespoon; a cup; a quart; a gallon, etc. It is simply and only a common unit of measure (volume) between the various ingredients. It is simply a way to express a relative ratio of the various ingredients to each other in a volume amount (1 scoop of this, 1/2 scoop of that, and 2.5 scoops of something else). Plus, for most of us, it is easier to remember 'parts' and to share a recipe in those terms with another rehabilitator.
So where do these weights come in?
Is this as easy as just taking all of the ingredients, finding the weight of one of them, and then multiplying the other ingredients by that amount?
For example, searching the internet for the weight of a tablespoon of water shows it's about 15 grams. In the Fox Valley recipe described above, I just take 15 grams of the dry powder and mix with 30 grams of water to arrive at the 1 part powder:2 parts water formula recipe? Did I get that right?
Not exactly, but you did get the correct water weight for 2 parts (in this case tablespoons). However, the (1 part) dry powder weighs about 6.9 grams per tablespoon. So simply following the math above, you would have more than doubled the appropriate amount of powder. Not good.
It is critical to remember, that if weighing the ingredients when making formula, you first obtain the weight of each individual ingredient (usually in grams) and use those weights for the corresponding parts. For example:
One part (TBSP) of Fox Valley 32/40 dry powder = 6.9 grams
Two parts (TBSPs) of water (2 x 15) = 30.0 grams
Total formula weight (combined ingredients, or 6.9 + 30.0) = 36.9 grams
Where do I get the weights for ingredients
WildAgain's Wildlife Formula Calculator contains almost all of the products, and their respective weights, used by rehabilitators to construct substitute milk formulas for wild mammal babies. If you prefer to think about and input your recipe into the calculator in 'parts' , the nutrition calculator does the math to convert each ingredient to the correct weight (in grams) for your recipe.
But I still need to weigh the ingredients
Yes, you do. To make it easy, the article on measurement provides an easy tutorial and guide on how to do just that.
Just remember, not all ingredients weigh the same!!!