Homemade Baking Powder with No Aluminum

Baking Powder is a wonderful thing.  Unlike yeast, it leavens so quickly that the resulting baked goods are called "quick-breads".  The upside of modern baking powder is it's effective at making batters and breads rise into light fluffy baked goods without having to take the time for yeast fermentation.  The downside is the that one of the key ingredients is an acidic salt made from aluminum (or "aluminium" as my British friends would say).  I'll try to answer the questions: what is baking powder, how does it work, are there any downsides, and can it be improved?

How Does Baking Powder Work?

Baking powder is a mixture of a weak alkali (i.e. baking soda) and a weak acid.  The two don't react with each other) because they are both dry.  However, when they are moistened by the liquid in the dough or batter, or in some instances heated, then they react with each other and in an alkali/acid chemical reaction that produces carbon dioxide (chemical symbol is CO₂ - think of the foaming eruption of the ubiquitous third-grade science fair "Volcano").  The CO₂ bubbles get trapped in the stretchiness of the batter or dough (usually from the gluten) and then cooked into place.  


The acid in a baking powder can be either fast-acting or slow-acting.  A fast-acting acid (e.g. tartaric acid found in cream-of-tartar) reacts in a wet mixture with the baking soda at room temperature, whereas a slow-acting acid doesn't react until it is heated in an oven.  Most modern baking powders contain both fast- and slow-acting acids.  The are called double acting because the leavening occurs initially when the the powder is exposed to moisture, and then again when it is heated.  That makes this kind of baking powder more reliable (that is why in the Anne of Green Gables series Lucy Maude Montgomery called the fictional company the Rollins Reliable Baking Powder Co.) than single acting baking powders which contain only one acid (i.e. leavening occurs right away but if you later agitate the batter or dough too much it can lose some of its puff by popping the CO₂ bubbles).

The trouble with Baking Powder 

The slow-acting acid in baking powder that is so conveniently heat-activated is typically either sodium aluminium sulfate or sodium aluminum phosphate.  Both are acidic salts derived from the metal aluminum.  There are two issues with that.  One is that it tastes metallic and that flavor transfers into your baked goods.  The other issue is the potential health risks associated with ingesting aluminum.  The US Government's National Institutes of Health runs an online site called ToxNet which is a repository of information about the toxicity of various substances.  Relative to Sodium Aluminum Sulfate their site notes under the "Neurological" section of "Clinical Effects" that:

"Aluminum accumulates in brain tissue and is a neurotoxic agent. Ataxia and seizures have been reported following ingestions and in patients with compromised renal function receiving bladder irrigations."

There are alternatives:

First of all, there are commercial Baking Powders that do not have aluminum in them.  The most available one in the US is one called Rumford Aluminum Free Baking Powder made by Clabber Girl (thanks to my Aunt Chita for telling me about Rumford).  It is significantly more expensive than regular baking powder but the food you make with it tastes better and you skip the aluminum.

The second alternative is to make the baking powder yourself.  You can make baking powder at home with readily available ingredients.  The advantages are that you know exactly what's in it, and that it costs just pennies.  The disadvantage is that it is single acting meaning that you'll want to be a little more careful about how much you handle the batter or dough between when you first mix it and when you bake it.

How to Make Homemade Baking Powder

There are three basic ingredients in homemade baking powder: 1. Baking Soda (serves as weak alkali)   2. Weak Powdered Acid   3. Powdered Starch (serves to absorb moisture so the other two don't accidentally activate).  The most readily available acidic powder is cream of tartar (a byproduct of the wine-making process).  You should be able to buy this in bulk at stores like Winco etc. that sell bulk spices so it's not so expensive.  I purchased a large supply of Citric Acid online (you can sometimes find this in smaller packets at the Mexican markets where it's called "acido") to make homemade dishwashing detergent and so I experimented with that and provide you a recipe below.  Most people use cornstarch for the 3rd ingredient but potato starch would work just as well.  

Here are two recipes:

• 1 Tbsp Baking Soda
• 2 Tbsp Cream of Tartar
• 1 Tbsp Cornstarch

or 

• 1 Tbsp Baking Soda
• 1/2 Tbsp Citric Acid
• 2 Tbsp Corn Starch

Try making your own.  It's easy, inexpensive, tastes better, and skips the aluminum.  Enjoy!