The south of England has proved a propagating haven for a plant more usually associated with mountainous Japan. Former Sienna chef-proprietor Russell Brown reports
The ‘Home-grown harvest' series of articles is all about the best of British produce, so it may seem odd to be talking about wasabi. But this isn't the bright green product in a tube, it's the fresh plant, grown by the Wasabi Company in the south of England, at the only wasabi farm in Europe. Apparently, old watercress beds that are too small or have unsuitable terrain make for very good wasabi farms.
Cold spring water, gravel beds and plenty of shade seem to mimic the growing conditions of Japanese mountainsides with considerable success. But it isn't really as simple as that; there is a huge amount of science, trial and error and craft behind these operations
Wasabi has been cultivated since 1600 BC, originally for its medicinal rather than culinary properties. The whole plant is edible, not only the rhizome, but also the stems, leaves and flowers. The most favoured method of growing is known as sawa, which refers to a semi-aquatic procedure said to deliver better flavour. A big part of the challenge for the Wasabi Company is getting across the difference between the fresh product and what typically comes in a tube, in which the actual wasabi content can be as low as 2%.
The way wasabi is prepared and used is critical. The rhizome needs to be grated very finely to release the true flavour. Traditionally, wasabi was grated on shark skin, but modern plastic and metal graters offer an environmentally acceptable alternative. These graters are different to a traditional grater, as the product remains on the tool's surface, which is made up of small raised dots or spikes, rather than passing through the holes of the grater. This produces a slightly sticky paste that can be rolled into balls with a stiff bamboo brush to prevent oxidation. Once grated, the flavour fades over a 20-minute period, leaving more sweetness. The heat comes from the myrosinase which, as it dissipates, leaves the glucosinolates. These are part of the plant's natural defence mechanism.
The rhizome is trimmed of its roots, and any dark patches can be removed to give a cleaner paste. The flavour changes from the stem end to the root, with the stem end giving a milder heat. The flavour is complex, with notes of green almond or cobnuts and a creamy taste.
The heat is more of a menthol heat, dispersing into the nasal passages, rather than a chilli heat, which stays in the mouth. As you grate more towards the middle of the rhizome, the flavour is more floral and the heat intensifies. The leaves are grassy and crunchy and also have some heat to them.
Wasabi has an effect similar to smelling salts and the science behind this has been used in making a prototype smoke alarm for the deaf, which received the 2011 Nobel Prize in Chemistry. The researchers determined the concentration of airborne wasabi needed to wake people in an emergency.
The main way wasabi is used is in a paste as a condiment, but it does have a much wider range of applications, and, although Japanese restaurants are the main customers, many other chefs do incorporate it into their menus. Kyoto Kitchen in Winchester is a big local supporter and uses the leaves instead of nori in some of its maki rolls. Melissa Thompson from Japanese comfort food company Fowl Mouths runs pop-ups and supper clubs in London, and her kara-age chicken with wasabi coleslaw is rapidly becoming recognised as one of her signature dishes. And at Gravetye Manor, head chef George Blogg is using it in a lunch dish of cured organic salmon with fennel tempura, citrus, shiso and English wasabi.
Wasabi is grown all year but in relatively small quantities, which can affect supply. Buy direct from the growers via their website at www.thewasabicompany.co.uk
Prices vary depending on root size, but the best-value smaller rhizomes cost £22.50 per 100g.
Buying and storage tips
Nick Russell, the Wasabi Company
- The rhizome is supplied wrapped in damp muslin
- Keep in an unsealed plastic bag, as delivered, in the fridge
- Do not seal in plastic as air circulation is required
- Rinse in cold water every 2-3 days
- The product will keep for up to two weeks
Recipe: Wasabi, onion and almond milk set cream
- 1tbs olive oil
- 2 medium onions, diced
- 300ml unsweetened almond milk
- Freshly grated wasabi to taste
- 1/2tsp Dijon mustard
- Maldon sea salt
- White wine vinegar to taste
- 2 leaves of gelatine, soaked in cold water
Start by sweating the onions gently in the olive oil until completely tender. Add the almond milk and blitz to a completely smooth purée. Pass through a fine chinois and then season with the wasabi, mustard, salt and vinegar.
Warm a few tablespoons of the cream and add the gelatine, stirring to dissolve completely. Whisk the gelatine mix back into the remainder of the cream, scraping the pan out well. Place in the fridge until the mix just starts to set. Whisk well and then pour into six small pudding basins and allow to set in the fridge overnight.
Serve with rare roast beef fillet or venison loin, and garnish with leaves and some fresh wasabi.
Recipe: Tomato salad with tomato and wasabi essence and wasabi dressing
For the tomato essence
- 800g ripe tomatoes plus their vines
- 1tsp Maldon sea salt
- 10g wasabi, grated
- 1 sprig of basil
For the dressing
- 100ml tomato essence
- 50g crème fraÁ®che
- 25g good-quality mayonnaise
- Maldon sea salt
- Wasabi to taste
Roughly chop the tomatoes and the vines, place in a bowl and mix with the remaining ingredients. Wrap with clingfilm and leave somewhere warm for at least six hours, preferably overnight. Strain through a fine chinois without pressing on the pulp. Chill the resulting liquid.
Reduce the tomato essence to a light syrup and allow to cool. Blend in the crème fraÁ®che and mayonnaise. Add fresh wasabi to taste and season.
To serve, mix fresh wasabi into the tomato essence and serve in shot glasses. Use the dressing to garnish a salad of mixed heritage tomatoes and finish each plate with a little freshly grated wasabi.
Plates supplied by CCS
Russell Brown ran the Michelin-starred, three-AA-rosette Sienna restaurant in Dorchester, Dorset, for 12 years with his wife Eléna. He launched his website and consultancy business Creative about Cuisine last year. He specialises in restaurant consultancy and photography.
Latest video from The Caterer