Comparative test of grape leaves for edibility

Introduction

Leaves from grape vines (Vitis vinifera) have long been used in Mediterranean cookery eg. in Dolmas (Greece), Koupepia (Cyprus), Warek Enab (Lebanon), Yebreh (Israel) etc. These recipes all use vine leaves as wrapping for parcels of other food. More recently they are sometimes used in sauces and grape leaf pickles (often after being blanched and brined).

The great nutritional content of vine leaves was highlighted by a recent paper on perennial vegetables (1), where in a comparison with several hundred other perennial vegetables, vine leaves proved very high in fibre, calcium, iron, magnesium, zinc and vitamin A.

Vine leaves are incredible easy to grow, as anyone who has a grape vine will know, so I first tried stir frying young vine leaves as a vegetable, using leaves from the Phoenix vine in my back garden. Result: they were excellent, with a good texture and tangy flavour. But would there be much variation between different grape cultivars?

Method

Leaves of 27 different vine cultivars from our collection were picked in early morning in early August. Only young leaves were picked near the shoot tips of the growing shoots. One of the great things about grape vines is that they continue producing young leaves from spring right through most of the summer.

For each cultivar, the leaves were roughly chopped into approximately 2cm strips, then they were stir fried in a hot pan with a little olive oil for about 1 minute until cooked.

The leaves were then tested by a panel of tasters, concentrating on flavour and texture, and scored out of 10.

Results

It was obvious there were going to be large differences, particularly between pure Vitis vinifera cultivars and the Vitis hybrids. Most of the hybrid cultivars have clearly thicker leaves, often with a woolly layer on the inside of the leaf, whereas the vinifera cultivars have waxy thinner leaves with no woolly layer.

Leaves of Chardonnay (pure V.vinifera). Thin, waxy grape leaves like this are almost always good to eat as a vegetable.

Leaves of Seyval Blanc, clearly showing woolly backs. This variety is 50% Vitis vinifera; 37% Vitis rupestris; 13% Vitis licencumii.

After cooking, most of the leaves from the hybrids were chewy, sometimes pleasantly so, but sometimes tough enough to be practically inedible. The pure vinifera leaves were mostly very tender and good quality.

Leaf scores and comments

Grape cultivars recommended for leaf cultivation

The top scoring cultivars from above are listed below. It is worth noting that the tasters went back to taste the best 6 cultivars at the end and rated the top two as Precoce Noir and Chardonnay.

Conclusions

Most of the pure V.vinifera leaves in our collection were tender, with a good tangy flavour, often described as lemony. Many of the hybrid vine cultivars had leaves which were tough or chewy and this poor texture often outweighed any good flavour profile. It could be that the toughness of texture is related to the proportion of non-vinifera species in the parentage, especially V.rupestris, which varies a lot.

The hybrid vine cultivars were mostly developed because of the resistance they have to vine phylloxera. This American vine pest was introduced into Europe and became a serious problem in the late 1800’s. Hybrids involving American vine species (V.aestivalis, V.rupestris and V.riparia) had some resistance but the quality of grapes was never considered as good as those from pure V.vinifera. The hybrids turned out to be much hardier with respect to climate and other vine diseases, so are still valued where vinifera grapes are still somewhat borderline.

However, for leaf production, pure vinifera cultivars will grow very well even in harsh climates where they will not fruit. They can be managed similar to tree vegetables, cut right back every year or two to a permanent trunk. Vine leaves can make a substantial contribution to vegetable nutrition and are a highly recommended addition to perennial and forest gardens.

Thanks to our tasters – Caitlin, Eamonn and Ellen.

Reference

1.     Toensmeier E, Ferguson R, Mehra M (2020) Perennial vegetables: A neglected resource for biodiversity, carbon sequestration, and nutrition. PLoS ONE 15(7): e0234611. https://doi.org/10.1371/journal.pone.0234611