The yeast is specially bred for surviving alcohol levels higher than regular yeast. It also has been bred to reduce any yeast flavor which is not wanted in beers and wines. The alcohol content is about 20% higher once its fermented out. Using it to make bread will probably not show much of a difference. With bread yeast, your goal for it is to only add CO2 to the dough which makes it rise. Its worth a try, but is a bit more costly compared to regular bread yeast cultures. Because its liquid in suspension, and I must assume its also refrigerated, you would probably add about 2-4 teaspoons for a 1 pound batch of bread.

ksrogers: I am going to try the yeast my friend gave me -- just as an experiment. I think I'll try using your suggested amounts.

I also asked this question on the Cooking Forum and Grainlady gave an historical answer that I'm sure is the correct one:

Posted by grainlady (My Page) on Sun, Jan 18, 09 at 9:24
SAF-Instant Yeast is a "superyeast". It's a product of genetic engineering. It's air dried instead of oven dried, and looks like tiny worms, compared to the much larger granuals of active dry yeast because of this process. It's a stronger type of yeast, fast-acting, and can be added directly to the dry ingredients rather than being proofed in liquid.
The first generation instant yeast was produced to mix directly with dry ingredients for quicker mixing (no proofing necessary). Because the home-users were accustomed to proofing their active dry yeast (which is what I think you are calling "regular yeast"), instant yeast was a failure in home use. They proofed it anyway, which reduced the strength of the yeast, and it didn't perform as well if proofed. The second generation of this product COULD be proofed, OR added directly to the dry ingredients, and is basically what instant yeast is today.

Instant yeast was used for many years in Europe before it was introduced in the United States and was first used in commercial application - by being able to add the dry yeast directly to the dry ingredients they were able to save time/money by eliminating yeast that required proofing.

If you substitute SAF-Instant yeast for active dry yeast, you need to use 25% less.

The "cousin" to the genetically modified "superyeast" Instant Yeast is fast (or quick)-rising yeast. These were reformulated from active dry yeast to preform in "instant" applications. For instance, one brand was simply made into smaller particles to dissolve rapidly and work faster than active dry yeast, rather than a genetic modification.

In the 1980's the Automated Bread Machine was developed for home use. Yeast companies begen to develop fast-acting yeast (Quick-Rise, Rapid-Rise and Bread Machine Yeast) for use in Bread Machines. These types were essential for the fast rise needed for the 1-hour cycle. As the name implies, fast-acting yeast shortens the rising time for dough. It is also reduced by 25% if you are substituting it in a recipe calling for active dry yeast.

When fast-acting yeast were originally introduced to the home baker, they were developed to make bread faster. You could eliminate proofing in water (add directly to the flour mixture - which saves 10 minutes) and eliminate one rise. After kneading, you cover the dough and allow it to rest for 10 minutes. Form dough, pan, and rise as usual for the final proofing.

For both Instant and Fast-Rising Yeast types (which are generally used in the same applications), they are commonly added directly to a portion of dry ingredients. The liquid added to this mixture needs to be 125-130°F to produce a quick rising dough. The warmer temperature is needed because when adding the warm water to a large bulk of ingredients, it quickly cools.

Active dry yeast (incorrectly called "regular" yeast) was developed during WWII to replace Cake Yeast. Fleishmann's, the first brand of active dry yeast was developed in 1943.

Cake yeast has 70% moisture content, requires refrigeration, has a short life of about 3-weeks, and was difficult to use during the war. Active Dry Yeast is 8% moisture. The development of active dry yeast made it easier to transport (no refrigeration needed) and use. It also had a longer shelf-life.

There is one more type of dry yeast - Osmotolerant Instant Active Dry Yeast. This type of yeast is recommended for dough characterized as sweet, salty or low absorption. It's beneficial in certain types of recipes because osmotic tolerance is called for because the amount of available water in these doughs is limited. Fermipan markets osmotolerant instant active dry yeast as Fermipan Brown, and SAF markets osmotolerant instant active dry yeast as SAF Gold.

-Grainlady

For more onfo on SAF yeasts head to King Arthur Flour. I use a brand that is sold in BJ's and Costco by the pound or two pounds. Its price is usually under $4.00 for that large amount. Compared to supermarket packets or those little jars, which are quite high in price. I store my yeast in the freezer in a air tight glass jar. It can keep well over a year. I don't bother proofing anymore, only because the newer yeasts dissolve and mix into flour much easier. Because your using a beer yeast which is quite different, the results might not give you as good a rise for bread as the true bread types. The term 'Super Yeast' has two meanings, one is stated by Grandlady and the other is a higher tolerance to alcohol needed to make higher alcohol beers and ales. KA offers both SAF yeasts for regular and sweet doughs. Then, you have a whole new area, sourdough yeast! There are many recent threads about the wild sour dough yeast cultures and how to care and duplicate them for a lifetime. I have my grandfathers sourdough culture still going after more than 100 years by now. Another yeast used in carbonated wines is a finishing yeast that has a low alcohol tolerence as it quickly dies when its exposed to sulfur in wines or sees high alcohol levels. I had a champaign culture that looked like dried chopped mushrooms. It was used to make Cold Duck, many years ago when I did wine making. A good additive for breads is a little ascorbic acid and a malt based sweetener. Also, if you like soft moist breads adding a little potato flour will work well. The ascorbic acid feeds the yeast as well as protecting the baked bread from early mold. Make sure you keep salt away from the yeast flour mixture, so mix it in after the dough has formed as salt will slow yeast down.

I wish I had seen your post before we went to Costco today.
Thanks to you both for your explanations!