French beans

[FluffyMuppet]

Last year I grew some heritage French beans (Scott's bean) from the HSL and we ate fresh green beans all summer and they were lovely.

This year I am growing them again (from saved seed) and also a climbing heritage variety (Dinah's climbing blue, I think).

I know that you can leave the beans to 'pod up' and eat the shelled beans as flageolet or leave them to dry and use them as haricot, but it's not something I have any experience of.

I have heard that some dried beans contain toxins which you have to soak/ cook out. Is this true for haricot beans? Are the toxins present in the freshly shelled beans too? (If not, why not??)

I'm going to attempt to leave a couple of plants alone for seed saving, which will give me far more seeds than I need (but it's better to save seed from more than one plant) so it would be nice to eat some of the spares.

Does anyone have any advice?

Thanks in advance
Muppet

[Dave]

There are toxins present in many dried beans especially kidney beans. These are known as lectins and can cause extreme stomach cramps and vomiting there is more information on - http://www.food.gov.uk/multimedia/pdfs/naturaltoxins

Other sites suggest the substance is known as hemaglutin so my educated guess is that hemaglutin is a lectin.
Another assumption is, as the beans are soaked or boiled to prevent any negative response there must be some kind of interaction that occurs in the absence of water. This is why fresh beans are not harmful as they will be quite high in water content.

I am speculating but it seems to make sense to me, if there is anyone with a clearer answer then please post it.

[FluffyMuppet]

It does look like they would be classed as kidney beans once dry.

The BBC Food page on pulses is quite helpful http://www.bbc.co.uk/food/back_to_basics/pulses.shtml

And the Vegan Organic Trust have a good information sheet which covers the whole process of growing, drying and cooking: http://www.veganorganic.net/info2.html