Grassy
Detected In: Aroma, flavor.
Described As: Alfalfa, crushed green leaves, fresh grass,
grass clippings, green leaves, hay, hedge trimmings, leafy, new-
mown hay, sagebrush.
Typical Origins: Aging, aldehydes.
Typical Concentrations in Beer: 0 mg/l.
Perception Threshold: 15 mg/l.
Beer Flavor Wheel Number: 0231.
Discussion: Caused by various compounds, including the
aldehydes hexanal (e.g., cis-3-hexenol), furfuryl octanoate, and
heptanal, which are produced by the use of large quantities of
hops (especially fresh, undried hops), oxidation of alcohols in
the finished beer, and/or the deterioration of improperly stored
malt or hops. Certain strains of hops also impart grassy flavors
and aromas to beer.
To Avoid: * Don’t use undried hops. * Don’t use aged
hops. * Properly store beer. * Avoid oxidation of wort or beer. *
Use a long wort boil to eliminate grassy aromas and flavors
(they are driven off by a long boil time).
When are Grassy Notes Appropriate?: Some strains of
English and American hops produce grassy notes when used in
large quantities, but such notes are only appropriate at low levels
and only in highly hopped beers (e.g., IPA).
Source : complete off-tastes beer fault guide, BJCP
Hypothèses et pistes :
- prolonger l'ébu initiale
- voir à utiliser des houblons pas trop anciens et surtout à ne pas oxygéner au moment du DH (amha, le problème vient de là, couplé éventuellement à un pH trop haut du moût / bière et/ou lié à la souche de levure)
