why does the yeast seem to be different here?

I have been trying to make breads and have had no real success. Where as in the states my breads were always very good. I have noticed that the bread I make here, seems to have a very potent yeast taste in it. As I have scoured the wirral simply looking for yeast, the only thing i could find was from ASDA and the yeast were in wierd little hard balls. But not knowing any better, I have been using the same measurements as I would have in the states.
Are these little round yeasties a different strand? I am used to the find granules that you get from Red Star and the like in the states. Is there an alternative measurement guideline for this type? (the little balls)
I have recently been informed about the difference in flour and baking soda here. (explains why my bisquits dont turn out right and my cookies arent as fluffy as they used to be)
Any help is appreciated as the holidays approach and I am an avid baker at this time of year.
thanks

I have no idea about the little round ball yeast thing... but in most Tesco's and Sainsbury's I was able to find a little vacuum pack of yeast.  You have to go to the larger stores.  They also have it in little packets much like the USA.  I found you have to use a little less yeast in some cases.  Particularly in white breads.  If you use bread flour in the UK it already has a lot of added gluten in it which helps the rise and crumb.  I used to make wheat breads and those worked out better than the white breads at first.  I'm afraid though it's a bit of a guessing game and playing with the recipes.  Try mixing in a bit of plain flour and watch out for strong and extra strong flours.  Extra strong is loaded with gluten.

You could also just google UK versions of bread recipes to start until you learn how to adapt the US recipes. 

 

Thanks so much for your input vnicepeeps. 
I will be sure to look for those at our bigger ASDA and Tesco that we have here, I usually tend to stick to the small local one... hence my downfall. 
Thanks again!