Strawberry fare

RHS Journals

The Garden
July 2007

Strawberry fare

In the second part of her series on taste, Christine McFadden samples strawberries and discovers that it is not just what cultivar you grow, it is how you grow it that counts.

Images: Tim Sandall

For most of us, strawberries still represent summer, although the supermarkets want us to believe that summer never ends. Despite their year-round availability, strawberries, with their intense fragrance, majestic colour and glossy, dimpled sheen, never fail to allure.

For the home gardener, the benefits of growing strawberries are many. Shelf life and shipping criteria are not important to you, so you can choose wonderfully flavoured cultivars rarely found in supermarkets. Most importantly, you can pick them fully ripe, at their peak of flavour.

The subject of taste is complex and subjective (see The Garden , April, pp260– 263), but at a special tasting held last year, a panel of experts, led by Raymond Blanc, Chef Patron of Le Manoir aux Quat’Saisons restaurant in Oxfordshire, assessed the qualities of several cultivars in an attempt to define what constitutes the quintessential strawberry – and to establish a benchmark for overall quality. As Raymond said, ‘Once you recognise these qualities, you know without doubt when you find a good one, whether it’s a supermarket berry or one you have grown yourself.’

Tasting trial

The panel tested six cultivars, two of which (‘Florence’ and ‘Alice’), though fairly new introductions, had done well in other trials and were used as controls. Three, still undergoing breeding trials (and not available to the public), were only identified by code numbers. A sixth cultivar, ‘Mara des Bois’, was supplied by Raymond’s kitchen at Le Manoir because he rates it highly for its flavour.

The two controls were tasted first, to give a standard against which to measure the cultivars still under development. Good-looking ‘Florence’ was immediately striking: a glossy, pillarbox-red, attractively heart-shaped berry, with just the right amount of seeds. In contrast, ‘Alice’ had rather too many seeds, which dulled its gloss somewhat, though this was redeemed by a vibrant red colour.

Having acknowledged that appearance plays a significant part in the perception of strawberry quality, Raymond questioned whether gloss contributes to flavour or is simply ‘for sex appeal’. ‘The sheen,’ said fruit grower Will Sibley, ‘comes from a natural wax, which helps the fruit to retain moisture.’ Most of the panel, however, considered ‘Florence’ to be watery rather than juicy, though some thought it dry. ‘Alice’ fared no better: it was felt to be ‘watery’ or ‘seedy’, though Raymond charitably described it as juicy.

Aroma is an important component of taste. ‘The initial fragrance contributes to our expectation and ultimate experience of flavour,’ said Raymond. ‘Florence’, with its pleasing scent, passed this test; ‘Alice’ was disappointingly lacking.

Striking a balance

The tasters then considered the balance of acidity and sweetness, essential for the enjoyment of any fruit. Raymond insisted that acidity must never overwhelm sweetness. ‘Sweetness first, acidity or bitterness afterwards,’ he said. Long-lasting layers of flavour are also vital. ‘First a big strawberry taste, then the aromas, peachy or whatever. And then bitterness, a bit of acidity. That’s what a great taste is.’

Unfortunately, the two controls fell short of expectations. ‘Alice’ was neither sweet nor sour, merely bland and lacking strawberry flavour; Raymond declared it ‘flat, thin, with an acid tannic finish’. The slight sweetness of ‘Florence’ was masked by sourness, a disappointing imbalance.

With the aroma and flavour of the two controls firmly fixed in noses and taste buds, the panel moved on to assess the un-named cultivars. Though they are not yet (and may never be) available to the home grower, it was interesting to compare them with other cultivars. Fruit and vegetable product developer Richard Massey classed the new cultivars as being ‘middle-of-the-road’.

So far as colour was concerned, all three were decidedly anaemic. ‘As pale as death,’ said Raymond as he inspected one cultivar. He pointed out that first impressions are not everything. ‘Taste is immediate. It doesn’t take ten seconds, but when we prolong the process and have time to think, it’s a very different experience.’

The longed-for strawberry aroma was generally lacking in all three, although Nurdin Topham (Head Tutor at Raymond Blanc’s cookery school) detected a hint of it in one cultivar. As if to prove just how subjective such judgments can be, Nurdin rated its flavour and balance as reasonable, yet Raymond felt there wasn’t enough sourness and its balance was correspondingly poor. Will, on the other hand, thought the balance good, despite a ‘hint of cheese’ in the flavour.

The real deal

By now we were more than ready for a meaningful ‘strawberry experience’ as Raymond put it. From his own kitchens came ‘Mara des Bois’, a top-notch fruit that is too-easily-bruised for supermarket requirements, but potentially rewarding for the home grower. Even though the samples had been chilled, the aroma was sensational, impressing the entire panel with its concentrated perfume.

Though ‘Mara des Bois’ obviously fulfilled Raymond’s passion for layers of flavour, he pointed out a lack of acidity scarcely perceptible to the other panel members, and a slightly watery texture. Another of his favourites is ‘Gariguette’. ‘It’s much better: packed with juice and the flavour lasts forever, because it has just the right balance of sweetness and acidity,’ he said. Unfortunately, there were no samples available to try.

Growing awareness

The tasting, although limited to a small number of cultivars, illustrated a broad spectrum of strawberry development. Having tasted the berries and listened to the experts, it is apparent that the quintessential strawberry flavour has almost as much to do with luck and skill as genetic factors. Soil, location, aspect and harvesting time all have an effect, regardless of cultivar, for amateurs and professionals alike.

With more than 50 cultivars currently available, home growers are not short of choice, but it pays to choose one with good disease-resistance as well as taste. Although not rated highly at this tasting, ‘Alice’, a healthy late-season cultivar, will perform well throughout the UK and was given an Award of Garden Merit (AGM) in 2006. Midseason ‘Hapil’ scored highly for flavour in recent RHS fruit trials and holds an AGM, although it is prone to wilt. Among other entries, ‘Cambridge Late Pine’ (which has an intense wild strawberry taste, but was low-yielding and susceptible to soil-borne disease) and ‘Rosie’ did not achieve an agm, but were noted for their aromatic flavour.

Recommended for an AGM, but not yet widely available, ‘Maraline’ is well worth looking out for. It is high-yielding, wilt-tolerant, and well flavoured… but taste is such a personal subject, so why not try several cultivars, new and old, and have a mouthwatering trial of your own?

Growing for flavour

Good choice
Although taste is not the primary criterion for judging, cultivars with the Award of Garden Merit (AGM) are flavoursome, disease-resistant, reliable croppers. To maximise the chances of producing well-flavoured fruit, choose healthy, vigorous plants from certified virus-free stock.

Place in the sun
For the sugar development that is so vital to flavour, choose a sheltered spot where the plants will be in full sun for most of the day.

Strawberries do well in growing bags, pots, hanging baskets, under glass or plastic, or in the open ground. Special, extra deep strawberry growing bags encourage healthy root development. In hanging baskets or pots, use soil-based compost (such as John Innes No. 2 or No. 3) mixed with some water-retentive hanging-basket compost. Strawberries in open ground need good soil with a humus-rich top layer. Dig in well-rotted manure, compost or leafmould. Just before planting, rake in a balanced fertiliser, such as blood, fish and bonemeal, but avoid nitrogen-rich fertiliser, as it encourages lush leaves that will shade the fruit from the sun.

Micronutrients such as potassium and zinc, naturally present in the soil, are important for flavour: deficiencies are indicated by poor leaf development, yellowing and dying off.

Strawberries need good drainage. Avoid cold, dense, poorly drained clay soils, or plant them on earthed-up ridges.

Grow under glass or plastic to extend the season, but do not cover the plants over winter, as frosts help to initiate flowering.

Food for thought
Once established in nutrient-rich soil, strawberries are undemanding. When the fruit has set, water little and often; overwatering dilutes the sugars, resulting in a watery flavour and texture. Growing bags can dry out quickly, so check them often and keep them evenly moist.

Pick the fruit when it is fully ripe, when the volatile chemical compounds vital for aroma and flavour are fully developed. Pick the berries continuously as they reach maturity. If they are left on the plant, their sugar and acid levels plummet and the flavour becomes bland.

After cropping, apply a little low-phosphate/high-potash fertiliser to encourage next season’s flower buds.

Enhance the taste
To enjoy strawberries at their best, pick them the day you eat them. Avoid putting them in the fridge. If chilling is unavoidable, allow one to two hours for them to return to room temperature, ideally leaving the berries in a sunny spot to warm through.

Raymond Blanc recommends sprinkling sliced strawberries with sugar and leaving them for 20 minutes to draw out the juices and boost the flavour. A squeeze of lemon will help the flavour to last; a grinding of black pepper adds aromatic warmth.

Other good partners include a dash of Kirsch, or shredded leaves of cinnamon-scented holy basil ( Ocimum tenuiflorum ) scattered over the fruit just before serving. Strawberries also go well with lightly cooked rhubarb (and other soft fruit) in a summer crumble.

The results

Most strawberries are cultivars of Fragaria x ananassa . Those tasted were grown with minimum use of pesticides; they were assessed for appearance, aroma, flavour, texture and overall performance. Density, sweetness/acidity balance and ‘mouth-feel’ were also rated.