Malt, wort and beer samples representing a single
pilot brew were extracted from Celite columns with Freon
114. Total extracts were analyzed by gas
chromatography/mass spectrometry. Compounds were
identified that were unique or common to beer, wort or
malt and quantities present were determined for those
common to the three...
Hop derived bitter compounds, including alpha-acids, reduced and non-reduced iso-alpha-acids, were evaluated for their contribution to peak bitter intensity in lager beer. Alpha-acids are the precursors to the major bittering components in beer (iso-alpha-acids). Typically, alpha-acids do not survive the brewing process, but if a product is dry-hopped, they may...
Alpha acids are found in the lupulin glands of hops cones. These acids have no bitterness of their own, but can be isomerized and subsequently hydrogenated to form bitter iso-α-acids and tetrahydroiso-α-acids respectively. Current literature values for the detection thresholds of iso-α-acid and tetrahydroiso-α-acid in lager beer have been reported...
The stability of diacetyl in fermented milk and the removal of
diacetyl from beer were studied. A convenient method for the determination
of diacetyl in beer, established by Owades and Jakovac, was
modified and applied for flavor analyses of dairy products. Through
this method, diacetyl in 12 samples could be...
Staling in beer is inevitable. Oxidation and increased temperatures are the main causes of stale flavors in bottled beers. Since 1934, research has been done to identify compounds and pathways involved in creating stale flavors. Although many research papers report stale flavors, there is not a lexicon per se of...
When hops are added to beer, varying degrees of hoppy aroma persist in the finished beer as a result of a number of factors. Dry-hopping is a technique whereby hops are added to beer post-fermentation to leverage the maximum aroma potential of the hop essential oils while minimizing bitterness contribution...
This work set out to examine the potential contribution of five aliphatic lactones, γ-nonalactone, γ-decalactone, γ-dodecalactone, δ-decalactone and δ-dodecalactone to stone fruit aroma in beer. This work consists of three related studies; lactone olfaction thresholds, additive/synergistic aroma effects and a gas-chromatography-mass-spectrophometry method of analysis. First was the determination of these...
This study examined whether polyphenols contribute a harsh bitterness
to beer, and how polyphenols may otherwise modify beer bitterness in the
presence of iso-a-acids. The experimental portions of this project were
divided into effectively two segments. The first section of the study
encompassed groundwork polyphenol extraction development, and the
examination...
Beer is one of the most extensively consumed beverages world-wide and it is almost always brewed with hops (Humulus lupulus, L.). Hops provide beer with bitterness, aroma, flavor and texture and also enhance specific beer properties such as foam stability, clarity (colloidal stability), color, flavor stability and microbial stability. Hops...