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Checklist: This affects your perfect hop aroma

 1. Time of harvest

As the title suggests, there are many things that have to be observed in order to recreate a good hop aroma in beer. And it all starts right at the beginning of the “food chain”: each hop variety has only a time window of a few days for harvesting in ideal condition. If you harvest too early, the hop’s aroma hasn’t fully developed (the biogenesis of the hop aroma compounds has been interrupted, so to speak) and it mostly smells green, grassy and not very intense. If you harvest too late, it can take on oniony-spicy notes, oils may be lost, or the overall quality may deteriorate (key word: diseases). The desired aroma can only be obtained at the ideal time. What counts is not that the hop cones look green and lush, but that they have the proper smell.

Bad timing? You’ve missed the aroma!

2. Drying

Here, too, you – or rather the hop grower – can get a lot of things wrong, or right: the operative words are even filling and layering depth in the hop kiln, correct drying temperatures (mostly 62-65°C), air speeds and, of course, drying time. If the hops are not dried enough, they can rot during storage or, in extreme cases, self-combust. If drying is excessive, it causes the aromatic substances to evaporate.

Incorrect drying? Fire hazard!

3. Storing raw hops

Like most foodstuffs, hops like to be in dry, cool conditions: if possible raw hops should be stored at 0-5°C, until they are either used for brewing or further processed into a hop product (pellets or extract). The water content, which has already been regulated by means of drying, should be between 8 and 11.5%. At this point the term “traceability” should also be mentioned: for hops, complete traceability (i.e. from the hop garden to the grower and on to processing and the finished product) is guaranteed.

Storage too warm? The aroma takes flight!

4. Gentle hop processing

Caution is called for even when processing the raw hops to pellets: when hop powder is being pressed into pellets, the temperatures should not exceed 55°C and the pellets should be cooled afterwards. Incidentally, only approx. 3% of all hops harvested worldwide are used in the brewery in the form of raw hops; the rest is processed for pellets or extracts.

Incorrect pellet processing? Loss of quality!

5. Storage and transport of hops

Both the hop processor and the brewer should ensure that the hops or hop products are transported and stored in cool, dry conditions. Here, too, temperatures of <5°C are recommended for raw hops and pellets. And once the original product packaging has been opened, the hops should be brewed as quickly as possible or, ideally, be repacked oxygen-free. Many brewers save themselves the trouble of repacking by freezing the hops – that at least diminishes the oxidation processes and keeps the hops fresh for a longer time.

Incorrect storage? Degradation and oxidation!

6. Hop addition in the brewing process

The timing of the hop addition in the brewing process has a decisive influence on whether the hop oils are preserved in the beer or evaporate, or are degraded or separated. If dosage takes place at the beginning of the wort boil, most of the aromatic substances in the hops evaporate (making it bitter). Things look better towards the end of the boil, and addition in the whirlpool makes for even better prospects. To put it simply: the later the hop dosage, the more intense and the more similar to the original raw hop aroma (dry hopping!) the aroma in the finished beer will be.

Hops added too early? The hop aroma dissipates!

7. Hop dosage quantity

In addition to the timing of the dosage, the quantity of the hop dosage is, of course, crucial. “A lot helps a lot” is often true, but doubling the hop quantity seldom produces double the intensity of aroma in the beer. Nevertheless, there is no doubt that you cannot expect miracles from homeopathic doses of hops. A common question: “I have already doubled the hop dosage from 20 to 40 g per hl, but I’m still not getting the mango aroma I was expecting in the beer. What am I doing wrong???”

Too little? What a waste!

8. Influence of the brewing process in General

Everything in the brewing process that “touches” the hop oils leads to less hoppiness in the beer or to changes in the hop aroma. The choice of malt varieties and the boil time play a part. During fermentation aromatic substances are degraded or converted by the yeast, and the CO2 produced can expel the oils. Each yeast strain produces different aromas: on the one hand, because they convert the hop substances differently and, on the other, by forming fermentation by-products which in turn may also trigger aroma interactions with the hop aromas. Fermentation parameters, such as time and temperature, have an effect, and during filtration aromatic substances are also inevitably removed from the beer.

1 hop, 2 different beers? Different hop aroma!

9. Oxygen

Here we come to beer’s worst enemy: oxygen!!! It is known to age beer (and people) and is not exactly well disposed towards hop aroma! The hop bouquet in the fresh beer can be as heavenly as it likes, but if the oxygen levels are wrong, there won’t be much of it left after only a few weeks.

Oxygen? Get rid of it!

10. Storing the beer

Now, as a consumer you don’t have any influence on the quality of your beer (more on the occasion for drinking it). Therefore, you can only hope that your retailer of choice doesn’t leave the beer standing around too long in the warehouse in summery or even tropical temperatures. The hop aroma in the beer will deteriorate over time – and all the faster, the higher the storage temperatures. Can / must a very hoppy beer keep for a year? It’s more than doubtful! The beer will perhaps keep for a year, but not the hop aroma. It often happens that precisely the characteristic aroma notes disappear after 12 weeks. If bottling and storage are optimal, however, the aroma can be as fresh after six months as it was the first day.

Is the beer still fresh? Cheers!

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