s00da,
A long time ago, when I first got started on the conversion kick, Steve, the Administrator of this forum, started a thread on the conversion subject at
http://www.pizzamaking.com/forum/index.php/topic,82.msg579.html#msg579. I subsequently did some of my own weighings for several ingredients, including salt and dry yeast among others, and I also relied fairly heavily on data from the nutritiondata.com website (
http://www.nutritiondata.com/) to do conversions for other ingredients. When I couldn't find data at nutritiondata.com to do conversions, I used data on labels for ingredients, even though that data is not always accurate because of rounding factors. For those occasional ingredients for which I could not find any data to do conversions, I used a special digital scale (My Weigh 300-Z) capable of weighing small amounts of lightweight ingredients. I had to learn to hold my breath when using that scale because the normal act of breathing could change the readings. Ultimately, all of the conversion data found its way into the various dough calculating tools listed at
http://www.pizzamaking.com/dough_tools.html. In some cases, as when I discovered several different brands of ingredients, like vital wheat gluten, I averaged the conversion data for purposes of the dough calculating tools. It's important to keep in mind that there are several factors that can affect a given ingredient's weight, including its source, its age and how it is/was stored, whether it is hygroscopic (absorbs moisture from its surroundings), the accuracy of the scale used to weigh it, etc. I could use several methods to convert a volume of an ingredient, like salt and yeast, and get different weight values. Fortunately, they are usually not so different as to have a material effect on outcomes. When you get down to really small amounts of yeast, like 1/64 teaspoon, my scales can't weigh that small an amount. So, I use mini-measuring spoons like those shown at
http://www.pizzamaking.com/forum/index.php/topic,5583.msg47264.html#msg47264.
Salt is normally not a problem since the tools mentioned above give users the option of selecting the type of salt used, and the baker's percents for all of the forms of salt are the same. The tool provides the weight-to-volume conversion for each type of salt. However, conversions of cake yeast to ADY and IDY, in either direction, and where the baker's percents are not the same, can be more problematic. However, for yeast conversion purposes, I often use the yeast conversion table at
http://www.theartisan.net/convert_yeast_two.htm. I have also learned the rough conversions factors embedded in that table. For example, to convert cake yeast to ADY, the usual recommended method is to use 1/2 of the weight of the cake yeast; for conversion of the cake yeast to IDY, use 1/3 of the weight of the cake yeast. These conversions are not exact but they are usually close enough for our use. There are similar conversions from IDY to ADY and from ADY to IDY, for both volumes and weights. You either have to learn these conversions or use the yeast conversion table referenced above. I don't trust my memory well enough to remember all of the conversions, so I keep a copy of that conversion table at my computer side at all times.
Peter
