{"id":14949,"date":"2025-01-28T17:02:34","date_gmt":"2025-01-28T16:02:34","guid":{"rendered":"https:\/\/brewstock.fr\/?p=14949"},"modified":"2026-10-13T19:44:51","modified_gmt":"2026-10-13T17:44:51","slug":"secher-a-basse-temperature-la-cle-pour-booster-les-aromes-du-houblon-francais","status":"publish","type":"post","link":"https:\/\/brewstock.fr\/en\/low-temperature-drying-boost-french-hop-aromas\/","title":{"rendered":"Drying at low temperature: the key to boosting the aromas of French hops"},"content":{"rendered":"\n
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Why do French hops struggle to match the explosive aromas of American varieties? The answer may be hiding\u2026 in a low-tech dryer<\/h3>\n\n\n\n

For years, French brewers have faced a somewhat frustrating reality: French hops, though they have an excellent reputation for their noble varieties, struggle to compete with the fruity and resinous notes of US or New Zealand hops. Attempts have nevertheless been made since 2016-17 to grow American varieties (Cascade, Chinook...), but the aromatic results do not match those of their American counterparts. What if the solution lay not only in the varieties themselves, but in the way they are dried?<\/p>\n\n\n\n

At HOPSTOCK, we ran a study over two harvests with Inagro, Brewing Theory and Twistaroma, which reveals some interesting findings about hop drying. At 45\u00b0C and with dehumidified air, the aromatic compounds of the hops are preserved, giving livelier and more complex aromas.<\/p>\n\n\n\n

Why do US hops have such a good reputation?<\/strong><\/h4>\n\n\n\n

First, two key factors need to be understood: the climate and traditional drying methods.<\/p>\n\n\n\n

The Yakima Valley in the United States is known for its semi-desert climate. In September, relative humidity there is often below 30%. In France, by contrast, humidity regularly exceeds 60%, and even 90% during rainy spells. A cubic metre of air passing through the dryer is therefore up to 3x more effective there, which has a direct impact on hop drying.<\/p>\n\n\n\n

In traditional dryers, humid air is heated so that it expands and absorbs the moisture from the hops more easily. The problem: this method exposes the cones to high temperatures (60-67\u00b0C) for a sometimes prolonged period (4 to 6 hours in the US, but up to 15 hours in France). The result? What has no consequence at all for a bittering hop (alpha acids are more resistant to high temperatures) has a direct and significant impact on the essential oils, which are responsible for the aromas and which degrade (oxidation and evaporation)<\/p>\n\n\n\n

Traditional drying doesn\u2019t just dry the hops\u2026 it also dries out their aromas.<\/p>\n\n\n\n

The solution: low-temperature drying with dehumidification<\/strong><\/h4>\n\n\n\n

In light of this, HOPSTOCK has developed an innovative yet fairly low-tech solution: a low-temperature dehumidification dryer<\/a>. The principle? Reduce the hops\u2019 exposure to heat and humidity in order to preserve their aromatic compounds.<\/p>\n\n\n\n

\"Low-temperature<\/a><\/figure>\n\n\n\n

HOPSTOCK invested \u20ac200,000 of its own funds over a period of 5 years to design and build this prototype, which is both low-tech and quite innovative.<\/p>\n\n\n\n

How does it work?<\/strong>
The HOPSTOCK prototype combines three key elements:<\/p>\n\n\n\n

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  1. A dehumidifier<\/strong>: to extract the moisture from the air before it passes through the hops.<\/li>\n\n\n\n
  2. An air heat exchanger<\/strong>: to recover the heat without reintroducing the moisture.<\/li>\n\n\n\n
  3. An oil-fired boiler<\/strong>: to heat the air to a temperature of 45\u00b0C.<\/li>\n<\/ol>\n\n\n\n

    The air is thus recycled in a closed circuit, reducing both energy consumption and the time the hops spend exposed to unfavourable conditions.<\/p>\n\n\n\n

    The benefits in figures:<\/strong><\/p>\n\n\n\n