Published February 1, 2010. From Cook's Country.
While salt can be both friend and foe, mush is always a foe.
Most canned black beans have three main ingredients: beans, water, and salt. So how different could they taste? Plenty different, we found out when 22 test cooks and editors from America’s Test Kitchen sampled six national brands—three of them organic—in a blind test. We tasted them plain (drained and rinsed), and also in a test kitchen recipe for black bean soup.
The results neatly separated into three brands we like and three we don’t. Predictably, our tasters had a strong preference for well-seasoned beans. All brands add water to the beans, and all but one add salt (an organic brand adds a small amount of kombu, a salty seaweed). The three brands that scored the highest all have more than 400 milligrams of sodium per half-cup serving; the three low-scoring brands, all of them organic, contain much less sodium (between 15 and 140 mg). Simply adding salt to the organic brands didn’t help: The texture was still mushy and the seasoning superficial.
Texture was important, too, as tasters disliked mushy beans (again, the three organic brands). The difference between firm and mushy beans hinges on a balance between chemistry (in the form of salt and other additives) and process (how hot and how long the beans are cooked during canning). Aside from adding flavor, salt accelerates the softening of beans by breaking down the pectin in the cell walls. So you need salt for good flavor, but too much can make the beans mushy. This is why two of our salty, highly ranked brands, add calcium chloride, which counteracts the softening power of sodium by strengthening the pectin in the cell walls of the beans. So how does our winning brand achieve firm beans with lots of salt and no calcium chloride? That’s proprietary manufacturing information, we’re told, but odds are that to preserve more of their firm texture, they quickly processes their beans with less heat than the other brands (the three organic brands are dramatically overcooked).