Density of Instant Dry Yeast
I'm baking my way through Jeffrey Hamelman's 'Bread'. Because just my wife and I do the eating, I'm simply dividing the Metric Column in the recipes by 30 to obtain approximately one loaf -- the home column is not in metric and yields too many loaves for us.
Everything works out hunky-dory except for the Yeast amounts. My scale only has a resolution of 1 gram and I therefore have to convert to volume (in tsp).
For instance, Pain Rustique, needs 140g FRESH yeast. Divide by 30: 4.67g FRESH Yeast needed. Convert to INSTANT yeast: 4.67 * .33 = 1.54g INSTANT Yeast needed.
I now use a density of .6 to convert this to a millilter measure: 1.54g / .6 = 2.57ml instant yeast.
This, in teaspoons, is about .5 teaspoon.
(Of course, I combine all these factors into a single factor ( 1 / 30 * .33 / .6 / 4.93 = 0.0037) that I use to multiply the original fresh yeast amount)
BUT, I'm uncomfortable by the density figure of .6 that I'm using. Today, I saw a reference claiming it was just .5 but I can't find that URL again.
Also, while I'm about it, is the density of INSTANT and ACTIVE DRY yeasts more or less the same?
I hope I'm not cluttering up the forum with a question that's been answered multiple times. Thanks.