Lúpulo e Alfa Ácidos

The hops cones or flowers are rich in resins, oils, tannins, proteins, and sugars among other things. The alpha and beta acids that are at the forefront of the packaged products are contained in the resins. Humulones, or alpha acids, are the most prominent bittering agent in hops. As the wort is heated, along with the hops, these alpha acids change in form and result in iso alpha acids, or isohumulones. These iso alpha acids tend to increase in bitterness. This is in contrast to the beta acids, or lupulones, which tend to convert into some bitter and non-bitter agents.

When you see hops labeled with an alpha hops percentage this refers to the measurement for the composition of alpha acids compared in weight to the rest of the elements in hops. This is shown in percent, and indicates the % weight of the primary bittering agent.

AAUs or alpha acid units are then used for creating recipes that can be followed regardless of volume. HBU refers to Homebrew Bittering Units. HBU's are calculated by taking the weight in hops multiplied by the alpha acid %. HBUs were created as a tool to use when calculating the amount of hops to use in say 5 gallons of homebrew. One ounce of 10 AAU hops will result in 10 HBUs. IBU stands for International Bitterness Units and is actual measurement for bitterness.

 

 

 

Humulene Oil Overview

Humulene is in a class of hydrocarbons known as sesquiterpene. It can lead the overall oil composition in some hops varieties but is generally less than that of myrcene. Humulene is found naturally in plants including Basil, Clove, some evergreen trees, and Hops. It has been linked to positive effects in dealing with illnesses such as yellow fever and even cancer. Humulene is linked closely with caryophyllene as they are commonly found together in nature. Some references will refer to them as one in the same. 

 

Humulene Fragrance

Humulene, much like other oils found in hops, is used in the perfume industry. Humulene’s aroma is robust on the senses and carries woody, earthy, and herbal character. Oxidation degrades its essence rapidly, and storing in air tight refridgerated packaging increases its storability.

Humulene Flavor

Humulene is not closely related to bitterness. It provides much more to the woody organic flavor of a beer. It is linked to the spice in coriander, and thus produce a spicy flavor over long boils or mash. 

 

Humulene in Brewing

Humulene has a relatively high boiling point (210 degrees F). With the high boiling point, and its high aromatic qualities, high-humulene hops are ideal for late additions to the boil. This gives them the opportunity to dissolve into the wort, and at the same time maintain their herbaceous fragrance. Below is a list of hops varieties ordered by their humulene content. 

 

Myrcene Overview

Myrcene is one of four essential oils found in the hops cone. Commonly referred to as beta-myrcene, and generally is the leader in volume compared to the other oils. This oil is extensively used in the perfume industry and can be synthesized, or come organically from plants....namely Humulus lupulus (Hops), Bay, Lemongrass, Verbena, and Snapdragon flowers. 

 

Myrcene Fragrance

Myrcene is highly flammable hydro carbon in the form of 7-methyl-3-methylideneocta-1,6-diene. In its natural form inside the cone, it is pungently fragrant. To the smell it has tones of grapes, peaches, vanilla, wine and is balsamic like. While at the same time the odor comes off as woody, green, herbaceous, and peppery. The fragrance is subdued to minimal levels with heat, and this prevents it from remaining prevalent after a boil or mash. 

 

Myrcene Flavor

Myrcene is a colorless clear oil that is referred to as a monoterpene. Its health effects have been studied throughout the science industry. The flavor somewhat matches its fragrance and will be orange-like and citrusy, with an earthy, even metallic flavor. With a boiling temperature of 147 degrees F, its flavor dissipates in much the same way as it's fragrance with high temperatures. 

 

Myrcene And Brewing

Myrcene impacts both the flavor and the aroma of beer. Due to its degradation of both of these qualities with heat, hops with high myrcene volume is commonly added during the final minutes of a boil, or is used for dry hopping in order to preserve its potency. Although the volume of this oil is generally not labeled on packaging, you can use the guide below to help in selecting the right variates of hops for experimenting in your brew. 

 

Caryophyllene Overview

Caryophyllene is one of the essential oils in the oil composition of hops. It volume is generally fractions of myrcene and also usually less than hunulene oil composition. Caryophyllene is an FDA approved food additive which is found in many common plants including Basil, Clove, Oregano, Pepper, Caraway, Cannibas, and Humus lupulus (Hops). Drug makers lack the incentive to approve caryophyllene for drug use with the FDA, since it is so readily available, although there is continued research. 

 

Caryophyllene is a sesquiterpinoid that comes in two forms (alpha and beta) which are generally found together (isocaryphollene). It’s a hydrocarbon, and much like myrcene is widely used in the perfume industry. Caryophyllene is also used in the food industry as a general spice and can be found in ice cream, beverages, baked goods, and condiments. 

 

Caryophyllene Fragrance

Caryophyllene’s fragrance is obvious when you split open a hops cone and has essence of a dry woody, spicy, earthy bouquet. Its smell can be sweet, and its link with the clove plant becomes apparent when you compare the two. Caryophyllene provides a lot to the character to what we know as ‘hoppy’ aroma. The fragrance oxidizes quickly when exposed to oxygen, and this diminishing return for the senses is evident when handling older or aged hops cones. 

 

Caryophyllene Flavor

Caryophyllene is used in many foods, and contributes a strong dry wood, pepper, and earthy spice flavor. It is a colorless to pale yellow liquid and tones of citrus may come to the finish. Caryophyllene’s herbal character contributes to the finished beer, and boiling accentuates the flavor. Below is a list of hops varieties ordered by their caryophyllene volume. 

 

Farnesene Overview

Farnesene is one of the more interesting oils due to its applications and effect in nature. Farnesene volume in the oil composition of hops is generally very low (< l%), although it can be relatively high in noble or aromatic varieties. It is also a sesquiterpine and occurs naturally in many plants including fruits such as apple, orange, mandarin, lime, and grapefruit, and also in pears, ginger, nutmeg, basil, and hops. 

 

Something unique about the compound is that it is actually emitted from a species of aphids as an alarm or defense mechanism. The odor is a signal to other aphids that there is a threat. Its interesting to consider if the the plants development of these oils isi a genetic defense mechanism itself. Oxidation of Farnesene is also linked to the deterioration of fruits such as apples and bananas, and is known as superfical scald and chilling injury respectively. 

 

 

Farnesene Fragrance

Farnesene is also used widely in the perfume industry due to its beautiful smell. It is also used in masks and powders. Farnesene's fragrance has been compared to that of magnolia flowers and having citrusy notes with green, woody, vegetative odor with hints of lavender. Its contribution to beer is significant for aromatic qualities. 

 

 

Farnesene Flavor

Farnesene is also used in many food applications due to its taking flavor. It adds essence of herbs and organic wood-like offsets. This characteristic makes it a great supplement in teas and juices. Farnesene is a pale yellow to clear yellow liquid. 

 

 

Farnesene and Brewing

High farnesene levels are favorable for both aroma and flavor in brewing. Farnesene deterioates rapidly with oxidation and can be preserved by sealed refrigerated storage. Farnesene's influence on aroma is worthy of displaying its oil volume composition on packaging, but this is not generally the case. Hops with farnesene are more appropriate for late additions to the boil, and dry hopping. 

 

Fonte: http://beerlegends.com/hops