But why does baking soda work? In baking soda, the oxygen on the sodium bicarbonate (above) grabs on to a hydrogen from the acid creating an H2O (water) molecule which is very happy on its own and leaves the molecule. Which means that all that is left is CO2 (that's right, the green house gas we have all been hearing so much about). The heat causes both the steam and the CO2 to expand (more later on expanding gases) and the batter rises. Baking powder is simply a mix of baking soda (base) and cream of tartar (acid) with a little corn starch thrown in as a filler. When dissolved in the liquid part of your recipe they mix, creating the gas. And the reaction occurs at room temp, so it is best to use any batter as soon as possible after you mix the liquids and powders. You don't want all those glorious bubbles to escape.
The products of mixing an acid and a base in the right ratios are neutral, so every good chemistry lab will have a box of baking soda sitting around just in case someone spills acid. When I was in high school I happened to knock over a graduated cylinder of hydrochloric acid (bad stuff). My teacher came running over at top speed with a box of baking soda and covered everything, the table, my lab notebook, and a little bit of me, with baking soda to neutralize the spill. Sodium bicarbonate also helps to neutralize excess stomach acid so it is great in a pinch if you run out of Tums or Alka Seltzer.
Now for the food!
This is my favorite fancy brownie recipe (featuring sodium bicarbonate in the form of baking powder). Whenever I have surprise dinner guests these will find their way onto the table. I nearly always have the ingredients on hand and they are extremely easy to make. I discovered this recipe at Sugar Cooking (http://sugarcooking.blogspot.com/2009/08/cappuccino-brownies.html) and it was adapted from the book Bars and Squares by Jill Snider.
Cappuccino Brownies
Brownie
1 cup chocolate chips
1/2 cup butter
3/4 cup white sugar
1/4 cup packed brown sugar
1 teaspoon vanilla
2 eggs
1 cup flour
1 Tablespoon instant coffee powder
1 Tablespoon coca powder
1/2 teaspoon baking powder
1/2 teaspoon salt
Preheat oven to 350 degrees. Butter an 8x8 pan. In a medium bowl combine the flour, coffee powder, cocoa powder, baking powder, and salt. Set aside. Put chocolate chips and butter in a large bowl and set over a sauce pan of simmering water (aka a pour man's double broiler), stirring until smooth. Turn off the heat. Whisk in the sugars and vanilla. Remove from pan. Add eggs one at a time. Fold in flour mixture. Pour into the prepared pan and bake 30-35 minutes (my oven runs a bit hot, and I prefer my brownies on the softer side so I usually bake mine about 25-30 minutes). Cool completely.
Frosting
2-1/2 teaspoons instant coffee powder
2 cups confectioners sugar
1-2 Tablespoons milk
1/4 cup butter
In a bowl combine coffee powder and 1 Tablespoon milk, stirring to dissolve. Add butter and sugar and beat until creamy, adding milk as necessary to obtain the desired consistency (I usually add at least one more Tablespoon). Spread evenly over the cooled brownies. Chill completely.
Glaze
1 cup chocolate chips
1/3 cup whipping cream
Put chocolate chips and whipping cream in a bowl over a saucepan of simmering water, stirring constantly until smooth. Let cool to lukewarm. Spread over frosting. Chill until chocolate is set, about one hour (mine usually don't make it that long, but if you want them to be firm and stackable let them chill the full time).
*Note on my delicious blob above. I not only didn't let them chill enough, I also seemed to undercook my brownies. But, as the title says, at least I didn't blow anything up.
No comments:
Post a Comment