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Rapid Rise Yeast

Maggie Glezer <glezer@mindspring.com>
Mon, 01 Jan 2007 14:38:45 -0500
v107.n002.3
Happy New Year to all of you bread bakers!

I have a little gift for you all: a bit of knowledge.  There has been 
a lot of myth bantered about recently by posters to this list, and I 
thought maybe I could set the record straight.  I give my yeast 
lecture every time I teach, and hope I can make a little headway here.

RapidRise yeast is Fleischmann's trademarked name for their instant 
yeast. It is not a distinct type of yeast. There are four types of 
yeast available to bakers: cream yeast, compressed yeast, active dry 
yeast, and instant active dry yeast. The first--creamed yeast--is 
only available to large wholesale bakers.  It is yeast in slurry form 
straight from the factory, containing all its original water.  It is 
pumpable, so highly desirable for large commercial bakeries.

Compressed yeast--the most active yeast available to home 
bakers--contrary to what people might be imagining--is creamed yeast 
with the extra water removed.  This yeast needs to be stored between 
33 and 40 degrees F and only has a shelf life of two weeks, so 
usually only larger bakeries use this type of yeast. Old time bakers 
prefer it for its amazing leavening ability.  A little goes a long, long way.

Active dry yeast is what most bakers have been using because it is so 
easy to store. It will keep, in its original packaging, for about a 
year at room temperature, making it a big improvement from the 
compressed yeast. However, it is the least active yeast--producing 
the least amount of gas, because of its large number of dead yeast 
cells--and must be proofed, that is, rehydrated in warm water, before 
use.  It is a pain to use and a relatively large amount must be used 
for decent leavening, so often recipes with active dry yeast have a 
yeasty odor and flavor.

To improve this yeast, a new type of cooler drying process was 
invented that resulted in a yeast product that had many more viable 
cells than the active dry and a finer grain, and so did not need to 
be proofed before use.  This is instant active dry yeast.

Rather than call this yeast by its name--instant active dry 
yeast--which is admittedly a mouthful, the yeast companies all use a 
unique trademarked name for their product. Fleischmann's calls their 
instant yeast RapidRise, and they also market an instant yeast with 
ascorbic acid included as an improver called Bread Machine 
yeast.  Red Star calls their instant yeast Quick-Rise yeast. SAF 
calls their yeast Perfect Rise.

All these yeasts have continued to be marketed in the three-envelope 
strips, with 7 grams yeast.  However, because the yeast has more 
viable cells, less needs to be used to produce the same leavening 
action as the old active dry yeast.  Thus, the yeast appears to act 
faster.  What home bakers need to know is that they just need to use 
slightly less yeast when converting between recipes calling for 
active dry yeast to recipes calling for instant yeast, usually about 
8% less.  For instance, while 1 teaspoon of active dry yeast can 
leaven about 1 pound of flour for ordinary bread recipes, 3/4 
teaspoon instant yeast is sufficient.  Yeast amounts can and should 
be adjusted according to temperature and time.

In the marvelous No Knead bread recipe, any brand of INSTANT yeast can be used.

I wish you all a healthy happy New Year, with lots of interesting and 
delicious bread adventures!

Maggie Glezer