Yeast effects on taste?

i may be showing my ignorance here, but how do different strains of yeast affect taste/flavor of beer? i would like to learn more about yeast so i can make better decisions when shopping and using it in my homebrews.
"a person who asks a question is a fool for a moment. one who never asks a question is a fool for a lifetime."

Yeast add flavors based on fermentation temps and type of yeast. A good place to start figuring out what flavors the yeast add is to go to the source:

www.wyeastlab.com

www.whitelabs.com

Check this out for a basis of knowledge, and pay attention to the flavor profiles listed for the diff temps.

Of course, there is nothing like experience, but this will give you a good starting point.

Sean

hey, everyone here is learning. So, no worries. There is ALWAYS new things to be learned, ask away.

Yeast is an interesting "ingredient" since it is alive. Like Sean says, experience is definately the best teacher. Even then it can throw you for a loop even using the same exact type becasue since it is alive, it changes.

Most yeast producers make recommendations as to their yeast strains flavor and temperature profiles and "suggested" beer styles. There is also attenuaton and flocculation rates, i.e. how much sugars they will consume and how readily they sediment. Following recipes and brewing software will also give you a feel for what yeasts to use. Once you think you have it figured out... You experiement!

Personally, I do not think I will ever truly claim to "undertand" the various yeasts, it is a bit daunting, but you can definately learn to use them and use them well.

Are you using dry or liquid yeasts right now? Dry has less strains available, liquid... mind boggling!

from my experience i have not found much differnce in different dry yeasts other than making a dryer or maltier beer. with liquid yeast you can add a myriad of flavors such as citrus like a belgian yeast, banana or clove in a weizen strain, or many other flavors depending on the strain. look at white labs page for some good info on the flavors their yeasts can impart.

Yeasts all put out chemicals other than, alcohol & CO2, called esters & aromatic hydrocarbons. Some styles depend on these chemicals.

Yeast selection is simple. Once you know what you want to brew, look at the recommended yeasts for the style (see sean's urls). If the recommended yeast for the style says, clean fermenting, high attenuation, buy a packet of Nottingham. If it says clean fermenting, moderate attenuation, buy Windsor dried.

Everything else, buy liquid and make a starter.