Hop into it

by Justine de Valicourt


We did a lot of different things to hops. Some worked, some didn’t. An exploration of the life of Humulus lupulus beyond beer.

When people ask, we say the lab is funded by independent foundations, private businesses, and government sources. This is true; though really, we should start saying producers, passion, and the sheer generosity of people.

We recently asked a hops supplier from Germany to send us 2 kg of two kinds of fresh hops to experiment on the curing process and the effects on beer taste. Our aim was to investigate flavours in other ways of preparing hops than the conventional quick-drying method. Yet instead of 2kg, we received 12 kg of each variety. 24 kg of fresh hops is a lot. A – lot. We don’t think this was a mistake, because we received even more a few days after. Beyond the fact that the lab smelled like legal cannabaceae for days – as did our urine – this free flood of hops was a great creative challenge and pushed us to investigate not only the drying process, but also their molecular composition and culinary potential. For two weeks, we almost stopped every other project to be able to process and use this mountain of hops.

I will reveal the punchline up-front: hops are terribly bitter and most of our recipes turned bitterly bad. But gaining this knowledge is indeed the aim of trying.

Contrary to what many people think, Nordic Food Lab is small. The team currently varies between 4 and 8 researchers at a time, depending of the season and the day of the week. This small scale and loose structure permit us to impose few limits on our thoughts. The team is formed with people with different backgrounds and strengths, but we are all curious. And we like answers.

Receiving 24kg of hops, or 40kg of herrings, or 150kg of quinces fuels our drive for knowledge. What to do with all this? How to keep it? How to make it delicious? Sometimes it is not the quantity but the thing itself that poses a creative challenge. What should we do with a very smelly beaver or just a tail of one of its fellows? Or with kilos of green, unripe plums?

It’s Christmas at every funky delivery. First, we look, then we smell, and, when possible, we taste it raw. For some ingredients, these first steps are enough to bring an idea that will take care of all of it. It was the case for the green plums: we tried different ways of curing them as if they were fresh olives. Some turned out awesome – a little acidic and crunchy, definitely delicious in a salsa verde or with a beer.

The hops were more difficult. Before receiving them, we had never heard about hops in anything other than alcoholic beverages. Knowing that hops are in the same family as marijuana and hemp made things easier. There are a lot more how-to-get-stoned-with-cannabis recipes out there than ones that use hops beyond brewing. Part of our conclusion was to not use the hops as a main ingredient, but rather as a subtle spice. Hops give a lot of flavour even in very low concentrations. The bitterness is also easier to manage in fats than in water, partly because the α-acids are hydrophobic, so the essential oils containing all these acids cannot be washed from the tongue with water. Oils and fats bond with the bitter molecules, preventing them from interacting with the taste buds. In other words, if those acids are mixed in oil, they are going to have less interaction with the tongue cells because they will stay ‘attached’ to the fatty molecules, and so the taste won’t be as potent as if they are in suspension in water.

We tried many many recipes.

A hop mayo was awful, as were all things involving infusion into water: soup, tea, etc.

We also tried to lacto-ferment some, as we do with almost every new ingredient we get. Didn’t work. Hops, as we already knew, inhibit bacterial growth (Simpson, 1993), especially lactobacilli, the bacteria responsible for wild lacto-fermentation, and beer spoilage.

From our research on marijuana, we decided to try butter, but preparing from scratch, using the hops to both infuse and culture the cream. We tried cold and warm infusion at 10% w/v. Don’t try the warm version. The cold infusion was fine, but nothing outstanding: a butter that tastes like hops.

We also found a recipe for hop and potato sourdough and made a bread from it. The result was a beautiful crusty bread with a nice texture – but the taste was the worst ever for a bread.

Yet there were some recipes with real potential. One was a gravlax exchanging the traditional dill for hops – fragrant and complex. Another discovery was grapeseed oil cold-infused with hop for few minutes – it turned out to be very fruity, green and with a little pinch of spiciness at the back of the throat, similar to some extra-virgin olive oil. We tried this technique with a variety of hops called Herkules, an infusion of 30 minutes with a concentration of 10% (10 parts fresh hops, 100 parts oil). Better results could probably be obtained with other hop varieties with lower alpha-acid content. Next season we will try with the wild hops we foraged in Christiania (yes, it’s hops, so nothing illegal).

We inoculated them with food-grade moulds: Aspergillus niger and Botryotinia fuckeliana. A. niger occurs in the process of making Pu-erh tea, but didn’t bring anything interesting to the hops, just some oxidized aromas. Botrytis, however, gave us something worth talking about. B. fuckeliana is also called noble rot, the fungus that infects some grapes and permits the famous Sauterne wine, among others. On the grape, Botrytis concentrate the solids (sugars, minerals, fruit acids) by making holes in the skin, allowing some of the water to evaporate.On the hop, by unknown means, it developed fruity and citrusy aromas. Further investigation has to be done to use these nobly-rotted hops in different kinds of beverages and food.

We had some leftover still sweet elderflower wine. We cooked it briefly to stop the fermentation and added hops (10%, cold-infused for 1hr) and kombucha mother. It turned out better than the wine by itself. We also made a hopped cherry wine, a hopped cider, a hopped malolactic fermented cider, and brewed a half apple juice half malt beer. All of these alcohols are quite interesting, some are even gaining some complexity with time, and even if they are not outstanding yet, they are a first step that could be taken further by others who know more about brewing and alcoholic beverages.

We brainstormed about how to make acceptable the strong bitterness that came with all our food trials, and decided to go for sweets. We made two types of toffees, both traditional recipes from Quebec. I guess we Quebecois have a sweet tooth. The first is called ‘Tire Ste-Catherine’ and is a smooth toffee made from sugar, molasses, water, vinegar, something alkaline and a few other things. It is pulled for a while when still warm and turns golden. We cold-infused the hops in water (10g of fresh hop/100mL of water) and the final flavour was interesting. Just hoppy enough to add some complexity to the taste and balance the sweetness.

The second recipe is more hoppy. We cold infused hops in cream (10g of fresh hop/100mL of cream) and forgot about it for more than a week. We finally used that cream to make ‘Sucre à la crème’ or Scottish tablet. In Quebec, it is a toffee traditionally made from maple syrup, cream and butter. Without the maple syrup, it can easily be done with brown sugar. The recipe is 1 parts cream hopped cream, 1 part of fresh cream, 6 parts sugar/syrup and 1 part of butter. Cook it until it reaches 118°C, let it cool down without disturbing until 50°C, then whisk and pour into a mould. At the whisking step, one can also add some nuts. Cut before it cools down completely. The whisking process brings seeds of crystallisation and makes the final texture sandy and moist at the same time, without sticking to your teeth. Miam! Is it better with hops? I’m not sure, but it might be more interesting to pair with coffee this way. Doing the same recipe with proper maple syrup and cream a little less infused hops would probably turn out even better.

No more bitter-sweet for now. Further directions include exploring some of the more aromatic varieties from Australia, New Zealand, and the US, investigating different types of bitterness (co-humulone is often thought to give a more rough bitterness at the end, for example), and looking deeper into different techniques for oxidation. One of our collaborators at the Jacobsen brewery has even told us about an experimental German variety he has with 0% alpha acid – that’s exciting. In addition, in the coming months we hope to smoke food with the hops along with wood chips, make new trials with alcohol infusion, and perfect the hop oil.

And even with all these trials, our freezer is still full of dried hops. Any ideas are welcome.