Most double-acting baking powders contain both cream of tartar and an aluminum salt (along with the sodium bicarbonate). The former works at room temperature. The latter only at oven temperature. Rumford baking powder substitutes monocalcium phosphate for both the cream of tartar and the aluminum salt. It works just like regular double-acting baking powder at room temperature but it rises less in the oven. It's sort of halfway between single-acting and double-acting in that respect. I use it because I think that the regular double-acting has a nasty taste. --Doug

Rita, thanks for the info. There's a Whole Foods market in my area, but it's about an hour's drive. I think it might be easier for me to just order the products online from Healthy Heart Market. I'm going to order both the baking powder & the baking soda. This low salt cooking is something else, isn't it? As you said in another thread, if a product is low fat, it usually is overflowing with salt & sugar. On the other hand, if a product is low salt, it can have more fat & sugar. I spend so much time in the grocery stores just examining labels. And when I find something truly low sodium, I buy several at a time. You never know when the store will stop carrying it. Please feel free to share good products, recipes, or tricks you use with me. I'm keeping track of all the acceptable products I find & where I obtained them. I'm also keeping track of recipes & main dishes that work. I started a blog just so I could record all the little "work around" solutions I've developed. It's really encouraging to me to have someone else on the forum who is dealing with this challenge. Your hubby is lucky to have you...

Funny to see this thread here today. I was doing a search on roast chicken (always looking for a new way!) and I read that if you take a chicken, really dry the skin well, then place a rub of salt, pepper, and baking powder on it, let it dry in the fridge for a day, you'll get a very crispy skin! Well, I had my chicken all brined (I love to brine to get a moist breast), so I removed it from the brine, rinsed, and dried the bird well. I used just a spoonful of baking powder and plenty of pepper to dust it all over, figuring there was enough salt from the brine. I paid special attention to getting it under the thighs where I've always had soggy skin. I could only fridge the bird for an hour before I had to roast it. To say the least, I was AMAZED. My chicken had the loveliest, most delicious, crispy skin I've ever gotten on a roast chicken!! I could eat the skin as a real treat from anywhere on the bird!!!! Anyone else tried this trick? It will be my way to ensure a crisp skin from now on!!!

I couldn't find other such proportion information for other brands. I used to use Calumet, and now use Rumford, mostly because it's what was on the shelf when I bought it. I do think it's noticeable that more of the Rumford reaction is in the bowl, but there are so many other reasons why that could be that I wouldn't call it definitive. I just adapt. If you were going to make a differentiation, I'd think that more heat rising might be good for something like pancakes, where they're made over time so the BP is discharging in the bowl, and you don't really want them to rise much before they get hot anyway. I don't think it makes any difference for a cake, where the method is to mix, pour and bake without stopping. Perhaps in a quickbread you'd want more of the reaction in the bowl so it won't go over in the oven? I don't think you can control it that much and it really depends more on things like the relative moisture content. Maybe we can get Grainlady back to answer that part of the question. A lot of people claim to be able to taste the aluminum in baked goods made with baking powder that contains it. I seem to think that things are more "delicate" with Rumsford, which might be that, might be the proportion of wet reaction, or might be a different kitchen and a new bag of flour.