Yeast - Active Dry vs. Instant

I'm working on testing out some new recipes for you folks and thought I'd include an important service announcement.   Yesterday I was working on making some english muffins, I was using a great recipe that is acclaimed across the web, written by a professional baker.  In my haste, I neglected to notice that the recipe called for instant yeast.  I went my merry way, measured out my active dry yeast and set about mixing my dough.  

Then I started kneading.  

Then I noticed all the little balls of active dry yeast where still present in my dough, like little bits of sand they weren't dissolving.  Then I had a giant "duh!" moment and went to check the recipe.  Sure enough, I had to start over because I hadn't activated my yeast and my first batch was never going to rise. 

Let this be a lesson to you all!  So, what is the difference between active dry yeast and instant yeast?  There is one important difference - instant yeast can be added directly to your recipe, and active dry yeast needs to be "activated" first by being dissolved in warm liquid.   It is possible to substitute active dry for instant like I did by activating it and using a little more than you would if you were using the instant yeast. 

Read my last post on yeast for more details on how to properly activate it, and also check out this Yeast FAQ over at The Fresh Loaf for more info on the differences between active dry and instant.