One of our local mega-supermarkets had a sale on canned soup. A 284 ml can of Campbell soup for 67 cents! They were also selling Sapporo Ichiban noodles for 97 cents a packet. It occurred to me that I do not have a clue how much a portion of my home made soup costs. So the next time I made a home-made potato soup I did an economic analysis. Briefly, using 6 potatoes, 2 carrots, 1 parsnip and half a rutabaga as well as 40 g of lard and flour I got 8 portions about 330 ml each of this soup. The estimated cost: $1.27 per portion. Thus in purely economic terms my home made soup does not compare well with the sale items. I have not even included the time spent cooking in the analysis which would weigh heavily against the home cooking.
How about nutritional comparison? The Campbell cream of mushroom soup has 227 to 273 calories per can (depending on which can you buy). The noodles are 470 cal per packet. Using the known weights of the ingredients and on-line tables I calculated the calorie content of one portion of my potato soup at measly 135 cal!
What about salt? Everybody points out the high salt content in the ready-made foods. Surely my soup must be better and healthier! Well, you can buy the Campbell soups with various salt contents: Starting at 45 mg per can in the "no added salt variety" (tastes awful) all the way to 1800 mg in the regular variety. The noodles had 1870 mg per packet (and tasted like that, too).
I put three small teaspoonfuls of salt into my soup. I am guided by the taste when finishing the soup. I do not think I like my food excessively salty. I weighed the salt on a jewellers' scale - 6 grams per teaspoonful on average! Thus my one soup portion contains whopping 2.25 grams (2250 mg) of salt. I found it hard to believe and searched some of the old records of other soups we made in the past. Sure enough, the same amount of salt on average.
My home made soup tastes way better than anything in the cans although I could get used to the Sapporo Ichiban Noodles. However, the message is: Be careful before you get too smug about your "healthy home cooking".