The books say to use a yeast that will tolerate the temperature that you can ferment at. The one above has an ideal temperature range of 53 to 59 Fahrenheit, but can go as high as about 71 degrees. The ideal is recommended because temperatures outside this range may change the taste or introduce new flavors you never wanted in your beer. I can't seem to hit 59 until we get into the heart of winter. 63 degrees Fahrenheit seems to work well as I'm not getting any real strange flavors. Lager (refrigerating) over time should take care of any off flavors and I always lager for 3 weeks. I try to go for 6 but can't seem to leave the beer alone for that much time!
I will give liquid yeasts a quick try soon and then talk about it. If I don't notice any difference I might switch back to the dry. Economically, liquid yeasts are harder to prepare and cost about twice as much as the dry yeast. I think some homebrewers may stick with dry yeasts over the summer as there is some concern about shipping liquid yeast through the mail when it is hot.
Lots of books and instructions vary on how you are to use yeast in your beer. One method is just to get your beer under 70 degrees, after the boil, before you add your yeast to it. Another method is to put it in a cup of warn water, between 90 and 100 degrees, in the last hour before adding to your brew. I tried that too. I don't really know if it makes that much difference. After the boil, I get the wort down to 70 degrees. Warm the yeast in a cup of water. I then add it to the carboy after I've gotten my beer in. A good shake of the carboy for about 30 seconds is what is called aerating the beer.
I will be taking the plunge into liquid yeasts soon when I try to clone my first Paulaner Oktoberfest Wiesn. I'm aiming for end of October of 2015. I will try "Denny's Favorite" which is available at my local brew shop. It is supposed to accentuate the malt and caramel of the beer. The yeast has been a favorite of Denny Conn. Denny has been a homebrewer since 1998, a national beer judge of the BJCP, is on the governing committe for the American Homebrewing Association and is a contributing author as well as a co-author of books. The yeast is named for Denny Conn. I will give this a try and compare to other yeasts also.
If I was brewing a German Pilsner I might try Wyeast's recommended Wyeast 2007: Pilsen Lager yeast strain.
I will try to let everyone know if decreasing the grain bill (buy less grains) will help improve yeast taste.