[gordonstrong]

I guess I don't get the point of trying to describe esters as an aroma or a flavor. An ester is a chemical compound, which has an aroma and a flavor. Some chemical compounds have one or the other, some also have a mouthfeel component.  One of the better references that I've seen that takes Meilgaard's flavor wheel and decomposes it into table form is this: http://hbd.org/brewery/library/FlavW.html

Look at the chart and see if something is described as an odor (aroma), taste, and/or mouthfeel.

[malzig]

Also, we all know from high school biology and Japanese cooking that we can probably only taste 5 basic flavors: sweet, salty, sour, bitter and umami.  Most if not all other "flavors" are actually aromas that our brain mis-interprets as flavor.  Esters are most probably aromas, but we may perceive them as flavors because our brains lie to us a lot.

[roguejim]

I guess I don't get the point of trying to describe esters as an aroma or a flavor. An ester is a chemical compound, which has an aroma and a flavor. Some chemical compounds have one or the other, some also have a mouthfeel component.  One of the better references that I've seen that takes Meilgaard's flavor wheel and decomposes it into table form is this: http://hbd.org/brewery/library/FlavW.html

Look at the chart and see if something is described as an odor (aroma), taste, and/or mouthfeel.

I think you answered your own question. 

I wanted to know whether esters referred to perceived aroma, or flavor.  It appears both.  Now I know.

[brushvalleybrewer]

I would like to brew a bitter with a bit of fruitiness.

1) Does SO-4 provide any fruitiness?

As far as aroma, I find that S-04 produces the aroma of apricots.

Try this… Rehydrate a sachet of S-04 in a zip-top bag, evacuating all of the air. After the appropriate time, open the top and give a good whiff. Fresh apricots.

[jaybeerman]

The production of esters can be affected by both the fermentation temperature and by the yeast pitching rate.  Pitching too little yeast encourages more yeast growth and ester production.  This is very desirable in Hefeweizens.  Overpitching reduces the yeast growth and ester production. 

Martin, I've also read things that indicate the opposite, i.e. yeast growth leads to decreased ester production. If you have time, I'd appreciate your take on this..

http://www.danstaryeast.com/library/yeast-growth

Denny/Martin, This is a question/topic that I've been fascinated with as well.  BrewChem 101 states, high yeast pitching rates will lead to increased ester production.  But my favorite quote on the subject is in Principles of Brewing Science; "Brewing procedures are quite important to ester production. These are HIGHLY VARIED and sometimes SEEMINGLY CONTRADICTORY."  A little later on, he states that under pitching [thus high rates of growth] encourages ester formation.  I have found in discussions with Brewing Science Institute that the brewing procedures necessary (under or over pitch) for ester production will change depending on which variety of yeast is being used; we also discussed fermentation temperature and aeration. Anyway, nice topic and I will enjoy reading everyone’s comments.  Cheers, j 

[denny]

Thanks for your thoughts, Jay.  I think it can be pretty much summed by by an old Firesign Theater line...."Everything you know is wrong"!

[jaybeerman]

Thanks for your thoughts, Jay.  I think it can be pretty much summed by by an old Firesign Theater line...."Everything you know is wrong"!

haha, yeah, ever feel like the more you learn the less you know

[beersk]

Is S-04 good in an English IPA?  I hope so because I plan to brew one with that yeast this weekend.

[bluesman]

Is S-04 good in an English IPA?  I hope so because I plan to brew one with that yeast this weekend.

Yes.  It is a well known commercial ale yeast known for it's fast fermentation and high flocculation.  It will lend a medium mouthfeel and some mild fruity esters to your beer.

[chumley]

I use WY1968 a lot, and I can definitely say that it is much fruitier when underpitched than when overpitched.  I don't make starters when brewing a bitter with it just so I can get more esters.  When I use the yeast cake to brew IPA after the bitter is done, it is far less fruity.

I have found the same is true with wiessbier yeasts 3068 and 3333. Far less banana when you use a yeast cake.

Back to the original question....while WY1968/WLP002 can give pretty good fruitiness, I have had my best luck with WLP023 Burton yeast.

Also....try the old trick of "dropping"....about 14 hours after you have pitched the yeast and fermentation has started, put your spigoted fermentation bucket on a table, open the spit, and let the fermenting wort "drop" into another primary fermenter.  That trick, which I read about years ago on the HBD, always seems to increase the esters a bit (as well as adding just a hint of diacetyl, which I also like.

Also, check your hops....I find that Target gives a kind of berry flavor to a bitter.