Hops

What are they and what are they used for?.

Hops haven’t always been used to make beer. The ancient Sumerians used herbs to bitter and flavour their beer. Early European concoctions also used herbs. Some had medicinal purposes, some purely for flavouring. Today we call non hopped, herb infused beverages “Gruit”. There is also barley wine, a strong alcoholic beverage, usually 10% or above, that is traditionally un-hopped, but modern versions may contain a small hop addition.

Hops and beer go together like, well, hops and beer. Strawberries and cream. Scones and jam. Like ice needs whiskey.

The History

Hops were originally used to preserve beer - extend its shelf life. Early adopters found that by adding hops, the beer lasted longer. Hops have anti-microbial properties. The compounds that impart bitterness to beer also inhibit bacteria and other microbes from propagating.

The German “Reinheitsgebot” lists and limits the ingredients in “bier” - the roots of which can be traced back to a 1516 Bavarian law. The original law says that the only ingredients that can be used are barley, water and hops. Back then they didn’t know or understand yeasts contribution to the process. This was done in order to preserve the quality of beer and set a standard price, but shows how long hops have been used in the process.

Beer has a much longer history though, dating back to the Persian and Sumerian empires. There is even evidence of fermented grains being prepared and consumed as far back as 8,000 BCE. Because of the alcohol content it was often safer to drink than water, and weaker versions (around 1-2%ABV) were served at breakfast and in the fields during the work day.

Once beer was produced in bulk we needed a way of preserving it - and along came hops, making it shelf stable.

The Plant

The hop plant - Humulus lupulus - a flowering bine, grows from a rhizome. In beer making we are only interested in the female plant, and specifically the hop ‘cones’.

Bines are different from vines - the don’t send out tendrils to grab on to their support, instead they wrap themselves around their support in a helix-like pattern.

There are hundreds of varieties of hops today, and statistically unusual is the fact that a disproportionate number of their varietal names start with A-C!!!

Plant Anatomy

Hop Cone. Bud like flowers produced on the female plant used in beer making.

Strig. the stalk that connects the hop cone to the bine and contains tannins.

Bract. The protective leaves that cover and contain the hop cone.

Bractioles. The soft base of the bract where the lupin gland forms.

Lupin gland. The yellowish/gold structures that contain resins, essential oils, alpha- and beta- acids.

Hop Packaging

Fresh or Wet Hops. Cones picked straight from the bine. They must be used within 24-36 hours before they decay.

Dried hops. Kiln dried to remove moisture but leave oils and other compounds in tact.

Pellet hops. The most common way of using hops in home brewing. Hop cones are dried, powdered and pressed into pellets. The common T-90 pellet is 90% vegetal and 10% lupulin.

Cryo hops. The lupulin is extracted under a cryogenic process, producing a higher alpha-acid concentration so you use less.

Hop Chemistry

Alpha Acid (A.A.) - determines the battering capability of the hop. They are activated during the boil (isomerisation) in the 30+ Minute additions. The longer the hop is boiled, the more A.A. is isomerism. Typical composition is 2%-20% of the hop.

Beta Acid - these acids mostly contribute to the preservation of the beer. Because the don’t isomerise, they contribute little to the bittering process, but over time will oxidise, showing up in beers that have a long fermentation and storage process.

Essential Oils - this is where the aroma and flavour comes from. Because of their volatility, these oils are evaporated during the boil. This is why flavour and aroma hops are added at the end of the boil, during a hopstand, or from dry hopping.