Full of Beans - Canned or Dried?

Ghent is promoting vegetarianism. The UK had National Vegetarian Week in May. Meat, thanks to its higher carbon footprint, seems to be out. What is an environmentally conscious protein seeker to do? Beans, it seems, are the answer. Yet just as people debate the environmental impacts of various types of meat, beans have a similar conundrum – canned or dried?

I am hardly the first to comment on this dilemma, but other discussions have focused exclusively on either taste or carbon footprints. Taste and environmental impact are, however, interrelated, and the debate really comes down to cooking time. Mark Bittman of the New York Times recently reassessed his bias against canned beans (chickpeas in this case), concluding canned beans are perfectly acceptable for dishes you don’t mind a bit mushy. Nina Shen Rastogi of Slate comes down slightly in favour of canned beans, as cooking efficiency at home radically varies. Let’s look at these claims a bit more carefully.

Bittman is indeed right that canned beans are perfectly acceptable for mushier dishes. In fact there are times when canned beans need to be cooked even further to achieve the desired consistency (hommous does come to mind here), but more often than not a quick heat on the hob is sufficient enough. Black beans to be served with Mexican or Caribbean dishes are perfectly fine canned. Perhaps the question isn’t so much what consistency you desire, but what role do beans play in the dish? Are they a supporting act or integral to its character? This is where Shen Rastogi’s analysis comes into play.

Rastogi’s piece uses data by one manufacturer in Oregon, with supplemental information from other sources. This probably speaks to the difficulty of getting comprehensive carbon footprints for foodstuffs as much as does the lack of scope. Plant efficiencies vary accordingly, but it seems to reasonable to assume that the production of cans, as Rastogi notes, is the largest contributor of greenhouse gas emissions.

In the UK, Tetra Pak containers (made primarily from wood products) are lighter and much less energy intensive in their production. Sainsbury’s has recently been carrying beans packaged in Teta Pak holders. Indeed Tetra Pak’s own analysis shows, perhaps not surprisingly, that the lifecycle impact of a Tetra Pak is much less than a steel can. The Guardian rightly points out, however, that Tetra Pak recycling is not yet as widespread and hence could complicate the argument. I, for one, walk 15 minutes to a Tetra Pak recycling “trial” depot, but many people may not have such conveniences, let alone time. It seems reasonable to assume that Tetra Pak recycling will increase in availability and that the long-term potential of such alternative packaging is positive. This weighs heavily in favour of Rastogi’s conclusion that canned (or ‘Pak’) beans err on the side of sustainability.

The other side of Rastogi’s analysis focuses on the cooking process of dried beans at home. She claims that beans require cooking of 30 minutes to 3 hours and bases the energy use on the high end of cooking times on a gas cooker. Granted there are huge variables when considering cooking method (pot, amount of water, type of cooker, type of bean, etc) and Rastogi acknowledges this. This is where taste comes into play. I have cooked dried black beans for 20-30 minutes after a 14-16 hour soaking and they were sufficiently cooked for my taste. I would imagine this brings down the energy usage significantly, though it seems even on an electric cooker it would not be possible to match the efficiency of a canning plant. Also note that the plastic packaging most dried beans come in is not recyclable and does not use any renewable resource at all, though the weight of this packaging is small. Perhaps the shop Unpackaged, in Islington, can be a solution for those living locally.

Let’s get back to taste. When beans are an essential component to a dish, simmered for a long time with herbs and other vegetables, they need to be cooked over the hob anyway. I have never found the ‘add canned beans in the last 10 minutes of cooking’ a suitable technique. Given you are going to be cooking on the high end of Rastogi’s analysis anyway, I would go with the dried beans. Nothing can compare to dried Haricot beans when making a rich tomato stew of sorts. The liquid stock that comes from soaking the beans can either be used in the dish, or reserved for future use, avoiding further purchase of stock.

The answer to the question of dried versus canned comes seems to be laced with caveats. This article was anything but scientific, but drew upon various sources and my own humble cooking experience. Let us then follow these guidelines:

1. For beans as side dish, or base, that only need to be heated briefly, Tetra-Pak beans are acceptable and perhaps even preferable. They probably wouldn’t be any worse than cooking dried-and-soaked beans for only 30 minutes on a gas cooker. A draw perhaps?
2. For beans as a component of a main dish, use dried-and-soaked beans. Reserve stock when possible.
3. Tetra Pak is preferable to steel where recycling facilities exist. These facilities should increase and in the meantime hassle your local council to expand its recycling offerings.
4. If you have an electric cooker, canned or Tetra Pak beans are always preferable unless you are making a long stewing dish.
5. The taste will vary on the bean and the sustainability will vary on the producer and supplier. Buy from suppliers and retailers you trust. Organic beans tend to be in more sustainable packaging in my experience.

Hopefully this demonstrates the headaches carbon footprinting can cause. There are just too many variables. Indeed Ragstogi is right when she says that no matter what method you choose, it will always be more carbon friendly than eating meat. However, are dairy consuming vegetarians less sustainable than dairy-free pesce-vegetarians? Let us leave that dilemma for another day.