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Cooked in water, they of course absorb some of it. Looking for weight, not volume conversion. If it varies by type, this is for Red Kidney Beans, but I'm guessing one general number can be good enough for most of them.

Cooking without soaking in a pressure cooker.

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  • Are you trying to figure out how much cooked beans (by weight) a given amount of dry beans will yield?
    – Preston
    Commented Nov 3, 2015 at 5:49
  • I happen to have some beans soaking. I didn't weigh them before-hand, but I know the volume I used so I can weigh another set, if that helps.
    – NadjaCS
    Commented Nov 4, 2015 at 1:27
  • Possible duplicate of How should I prepare dried chickpeas?
    – TFD
    Commented Nov 4, 2015 at 4:50

3 Answers 3

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I got very curious... My test included 4 sets...

Macro Organic Red Kidney Beans from Woolworths Australia selected. All beans were from the same bag... Water was at 18 C (tap/room temperature), 12 beans selected based on similar total weight.

  1. Water only... 190% weight.
  2. Water and Salt... 210% weight
  3. Water and Bicarbonate of soda 212% weight
  4. Control -- No water just air... 1gram change... We can call this calibration error.

As expected... the addition of salt or bicarbonate of soda increases the efficiency of absorption of water. Your experience will vary based on brand and freshness of the product.

PS My son and I had great fun measuring, pouring and splashing each other with water ... Part 2 is to see if any of these beans will grow... Does anyone have an opinion on whether "organic" beans should sprout and grow?

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  • If they are reasonably fresh they should grow. I've started plants from my pantry beans before. :-)
    – NadjaCS
    Commented Nov 4, 2015 at 15:28
  • 1
    I've had issue with some "organic" products recently... Fresh or not they will never grow as they have been treated/irradiated.
    – Adrian Hum
    Commented Nov 4, 2015 at 19:17
  • Good point, I guess it really depends on the source.
    – NadjaCS
    Commented Nov 4, 2015 at 19:18
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I'll try to update this after I finish cooking, but I have 3 pulses soaking right now that are about to be cooked. (red kidney beans, black chickpeas and urad dal)

For dry vs soaked, it seems the kidney beans (and both the black chickpeas and the dal) have pretty nearly exactly doubled in weight. When I cook them, I will include enough water to cover them. I know from experience that they will absorb some of it, but not all of it, but if you don't have enough water in there when you cook them in the pressure cooker, they will scorch.

It is a little hard to calculate exactly the cooked weight of the beans themselves without the cooking water because, at least for the dal and the kidney beans, they get pretty soft and some break up in the water. Unless you cook them with the exact amount of water they will absorb, it's pretty tough to say what is beans and what is water at a certain point.

For lentils and dals that don't need presoaking, I generally cook them with 1:2 dal:water and they absorb all of it and generally turn nearly to mush. For dal that needs to be soaked, I use the same method as the kidney beans -- just barely cover with water (note that this is additional water after soaking, and enough to cover their plumper volume). For those (whole urad dal, whole moong dal) it will absorb most of the water, but there will be some liquid left. I'd guess that it is probably less than half the original weight more in water.

So my best estimate is about 1 dry becomes 2-2.5 cooked, by weight.

I know you're asking about weight, but from a cooking perspective, for any lentils/dals, I always make sure to include twice the volume of water to the volume of the dry dal. For kidney beans i would probably cook them with 4x there volume of the dry beans. For anything where I expect to use some sort of sauce or gravy, I increase that. This is sort of the bare minimum so that they fully hydrate and don't scorch.

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I need this information as well, and, surprisingly, a Google search yielded few results, and those it did return were inconsistent. It occurred to me, that one way to get at an answer would be to compare the weights of dried and cooked beans that yield the same number of calories. Certainly some calories are lost in the cook water, which means my equivalent cooked weight will tend to be slightly high. I still think the comparison gets us a good approximation of the truth.

The data for the following table was gleaned from cronometer.com, which appears to derive its values from publicly accessible databases.

Bean           Dry (g)    Cooked (g)
Lentils        1000       2463
Black beans    1000       1773
Pinto beans    1000       2398
Chickpeas      1000       2265
Navy beans     1000       1632
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  • This probably all comes originally from the USDA's nutrition database. It seems like a good strategy -- I doubt very much that a significant number of calories are lost to the water -- but the dry versus cooked measurements may well have come from different sources and even different cultivars of beans (chickpeas, in particular, come in massively different sizes). Nevertheless, clever idea, and the results look entirely reasonable. And welcome to the site!
    – Sneftel
    Commented Jan 23 at 9:47

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