Green Beans, Runner Beans…. what is the difference? What’s the best way to cook them?

“1921: …after taking a summer job picking string beans for a dollar per twelve hour day, future President Richard Nixon acquired a life-long revulsion for the vegetable.”
Ian Crofton, A Curious History of Food and Drink
Runner beans v green beans, two different plants
What is the difference between green beans and runner beans? The answer is simple. Runner beans (phaseolus coccineus) and green beans (phaseolus vulgaris) are completely different plants.
But if you ask the difference between green beans, bobby beans, french beans, haricot verts, Kenyan beans… not to mention purple green and yellow green beans….. it all becomes a bit more complicated. Those are all types of green beans. This post tells you what you need to know.
1. Runner beans

Runner beans are big and flat. They are cheaper than green beans – the plants are more productive – but the rough, flat, green pods need to be destrung and then cut, diagonally, into smaller pieces before you can eat them. Boil them for three-four minutes, toss in butter and mint.
If you are short of time they are not worth bothering with because of the extra preparation, although fresh from the garden they can be sublime.
They’re in season from July to early October.
Exotic and different method for how to cure runner beans (with thanks to Stephen Harris)
These are a bit curious – the cordial is very sweet, but it does bring out the flavour. On their own, I think they are a bit much, but added to a green salad they would add a an unexpected crunchy texture, and fresh taste. The idea comes from Stephen Harris’s book, The Sportsman. Rather than making your own lime syrup as I describe below, you can simply use Rose’s lime cordial. This recipe would serve two or three people together with something else.
- Make some lime syrup by heating 200 ml (just under a cup) water with 200 g (approximately a cup) of caster sugar, and the zest of two limes. I also add in a sprig of rosemary. You need less than a quarter of this – use the rest to make a few gimlets.
- Slice about eight runner beans, lengthwise with a potato peeler, into very thin strips (throwing out stringy bits obviously). Put into a bowl with a tbsp of the syrup and a little sea salt.
- Leave half an hour, toss, and serve with a squeeze of lime, and some peppery olive oil drizzled over.

For a wonderful recipe for runner bean pickle, go to this post.
2. Green beans – different types and terms

Confusion arises because originally green beans also had to be destrung and they were also known as string beans. The string has now been bred out of green beans – a boon for the busy.
Green beans belong to the legume family – they are the unripe pods. They are eaten before the beans inside become mature, in the same way that sugar snap peas are eaten before the peas growing inside actually become peas. Green beans, unlike other legumes, have less protein and a lot more water…. The whole pod can be eaten as well as the seeds – the unripe fruit. This pod can be wide and flat, fleshy and round, or long slim and round.
There are two main types: bush, which grow into little bushes; and pole which climb and curl around trellises and other supports.
Further confusion arises from the fact that ‘green beans’ covers a lot of different types of green bean, one of which is the ‘haricot vert’ – the French bean whose name translated back into English means literally ‘green bean’.
a) ‘haricots verts’
These are thin, short and tender – they grow in the UK but they tend to do best in warmer climates.
Thinking of growing some? My gardening friends tell me that the French bean ‘cobra’ is particularly tender, and lacks strings. Easy to grow (it’s a climber…), it keeps producing from July to first frosts in October. ‘Amethyst’ on the other hand has proved in tests to have the biggest and longest crop, a strong flavour, and pretty flowers.

b) Kenyan beans
These are simply French beans which are grown in Kenya – they are available all year round and tend to be the thinnest and most tender of all the beans.
c) English Bobby beans (or snap bean)
These are thicker than the Kenyan and the French/haricot vert bean. Cook them al dente – they take a little longer than their French counterparts, about six or seven minutes. Rose Prince thinks they are better mixed in with other ingredients – for example in a salad with courgette ribbons, feta, mint, dill, chives and cracked pepper (go easy on the salt because of the feta). Or simply add them to Goodie-goodie Courgette Salad. You can stew them for ten minutes or longer in tomatoes, a little sugar, oil and garlic.
Bobby beans are good both hot and cold.

d) coloured green beans
Yet further confusion arises from the fact that you can get green beans which are, in fact, not green, but yellow or purple.
Yellow green beans
Yellow Wax are a pale blue colour with light, translucent yellow flesh. They have a slightly grassy, nutty taste. The nutty taste pairs well with brown butter. They go well dressed simply with oil and balsamic vinegar.
Looks are everything with Yellow Wax and they are shown off to good effect when thrown over salads (especially a salad Niçoise). They also go well with lobster and langoustines.
If you are thinking of growing them, ‘Cornetti Meraviglia di Venezia’ is a good type – grows quickly and completely without string.
Purple green beans
Purple beans also look amazing – although they turn green when cooked. The colour results from the same pigments which give red cabbage and purple cauliflower their colour.
Inside these beans are green, so to get a most impressive, two-tone effect slice young, tender purple beans down vertically and use almost raw – alternatively you could steam very briefly or plunge for seconds into boiling water and then refresh in ice water.
You can also throw them into stir fries right at the last minute. One rather nice idea is to make a salad of lightly cooked green beans and raw young purple ones, dress with olive oil, seasoning, and balsamic vinegar, and scatter over a mix of green and purple basil.
Royalty Purple and Trionfo Violetto are popular varieties.

Can you freeze green beans?
All types freeze well.
When is the season for green beans?
In Europe the season for fresh green beans is late summer – August.
Best method for how to cook green and runner beans (with thanks to Heston Blumenthal)
- Most green beans – whatever type – have been picked a long time before they reach the supermarket shelves. So top and tail, and cut into bite-size lengths (the quickest way to do this is with scissors), and soak the beans in cold water for a couple of hours before you come to cook them.
- Drain them and add them to a non-aluminium saucepan of lightly salted water already at a rolling boil – cover the pan with a lid. Yes, I know there’s a myth that covering the pan results in turning the vegetables brown, but it won’t – what it will do though is to bring the water more rapidly back to the boil. Once boiling you can uncover partially or completely.
- Cook for a maximum of eight minutes or less depending on thickness (more for runner beans or Bobby beans). Five minutes is usually fine. You want resistance, but not crunch. If you cook a little less, you can save yourself the bother of the next step – refreshing.
- Drain them, and refresh by either running under a very cold tap, or plunging into a bowl of iced water. Why? This doesn’t retain the greenness, as you may have read, but it does stop the cooking process.
- To reheat, put a mix of about half a cup of water, and about 50g/one-fifth of a brick of butter – about two ounces; also a tsp or so of smoked salt and generous grinds of pepper into the pan and get it hot. Add the beans. Once they are good and hot, drain and serve.

Ideas for what to do with green beans (allow 120g/4 oz beans per person)
- Elizabeth David, and the Irish chef Rory O’Connell (who teaches at Ballymaloe) serve their beans just plain with butter or olive oil, and freshly ground pepper. Top and tail good-looking beans and cut them into 2”/5 cm lengths. Boil them in very salty water for about five minutes – al dente – and serve anointed with the butter or oil and the pepper.
- They are a key ingredient in a classic salad Niçoise.
- Boil and serve with garlic and almonds (try marcona almonds). Nigella serves hers with a dressing of mustard, salt, lemon zest, garlic, cold water and olive oil, into which she adds a drop of almond essence (the sort you add to cakes). Then she adds flaked almonds.
- Add to a salad of beef tomatoes and dill. Add softly braised onions and garlic (black garlic goes especially well). Dress with olive oil, lemon.
- Hamburg manful green beans – serve with bacon.
- The Roman gourmet, Apicius, suggests either serving them with mustard, honey, pine kernels, rue (a kind of bitter herb), cumin and vinegar.
- or alternatively he suggests adding to a salad of chick peas, fish roe (or bottarga), eggs, fennel, pepper and balsamic vinegar.
- Pep them up a bit with spring onions, ginger and Sichuan pepper.
- Serve them with a little coconut for a slightly Indian approach.
- In her Flavour Thesaurus, Niki Segnit explains that walnut and basil pair well together – especially with green beans. Cook the beans as usual and anoint with walnut oil, torn basil, and some dry-fried chopped walnuts.
- Dress cooked beans with a little grainy mustard and some balsamic vinegar.
- Try adding cucumber for a fresh taste, and maybe some borage.
- Crush up toasted hazelnuts with garlic and a little Gentleman’s Relish (or an anchovy), stir in olive oil, use to dress beans.
- Heat a little sesame oil with grated fresh (or frozen) ginger, garlic, and sesame seeds and use to coat hot green beans.
- … or a simple dressing of olive oil, lemon and mint or basil.
This post is dedicated to Jackie Fiducia.
If you’re interested in a similar post on peas… sugar snaps… mange tout … follow this link.
If you’re interested in a ‘know your onions’ post follow this link.
The article does not really seem to answer the question of what is the difference between French beans, runner beans, green beans, etc. Can you tell what is really the difference?
Hello Dale, I’m sorry it’s not clear. In the first paragraph (‘runner beans v green beans’) I explain that runner beans and green beans are two completely different plants. Runner beans are phaseolus coccineus and green beans are phaseolus vulgaris. Then in section two of the post, (‘2. Green beans’) I explain that there are lots of different types of green beans but the differences between them are not great. I include French beans aka haricots verts as one example of a type of green bean. I hope that clears it up. All the best, SD