egnald
Member
Greetings from Nebraska,
Well, instead of working in the shop this morning I decided I should make something to eat and Peanut Brittle was the winner. This time of year I used to always make a few batches and take them in to work -- they never lasted very long. When I was growing up I was not a fan of Peanut Brittle. I think it was because few of the people that made it back then owned a candy thermometer, let alone an accurate candy thermometer, so it was often over cooked. That and premium peanuts were just not as prevalent or available 50 years ago.
There is some really cool chemistry involved in Peanut Brittle. The first is called Sugar Inversion. When sugar (disaccharide sucrose) is heated, in the presence of water it breaks down into monosaccharides, fructose and dextrose. Corn syrup which is a glucose and fructose sugar is produced by hydrolyzing cornstarch, usually with a dilute acid. Corn syrup also interferes with the ability of fructose to rejoin with dextrose. This prevents the sugar from crystalizing. At about 230 degrees F the mixture becomes saturated so the peanuts can be stirred in.
There is a small amount of amino acid in peanuts that contributes to the Maillard reaction. This is the reaction provides flavor development and causes foods to brown when they are being cooked. Think about roasted vegetables and seared meat. Along with any residual acid from the corn syrup and sugar inversion, the amino acid from the peanuts is also responsible for creating the carbon dioxide (CO2) that makes the sugar foam up just before it is poured out. This aeration is what gives peanut brittle it's texture otherwise it would have the glass like texture of a lollipop with peanuts embedded in it.
The final result of this chemistry can be very delicious.
Dave - PS I also attached a copy of my recipe if you would like to do a chemistry experiment of your own!
Well, instead of working in the shop this morning I decided I should make something to eat and Peanut Brittle was the winner. This time of year I used to always make a few batches and take them in to work -- they never lasted very long. When I was growing up I was not a fan of Peanut Brittle. I think it was because few of the people that made it back then owned a candy thermometer, let alone an accurate candy thermometer, so it was often over cooked. That and premium peanuts were just not as prevalent or available 50 years ago.
There is some really cool chemistry involved in Peanut Brittle. The first is called Sugar Inversion. When sugar (disaccharide sucrose) is heated, in the presence of water it breaks down into monosaccharides, fructose and dextrose. Corn syrup which is a glucose and fructose sugar is produced by hydrolyzing cornstarch, usually with a dilute acid. Corn syrup also interferes with the ability of fructose to rejoin with dextrose. This prevents the sugar from crystalizing. At about 230 degrees F the mixture becomes saturated so the peanuts can be stirred in.
There is a small amount of amino acid in peanuts that contributes to the Maillard reaction. This is the reaction provides flavor development and causes foods to brown when they are being cooked. Think about roasted vegetables and seared meat. Along with any residual acid from the corn syrup and sugar inversion, the amino acid from the peanuts is also responsible for creating the carbon dioxide (CO2) that makes the sugar foam up just before it is poured out. This aeration is what gives peanut brittle it's texture otherwise it would have the glass like texture of a lollipop with peanuts embedded in it.
The final result of this chemistry can be very delicious.
Dave - PS I also attached a copy of my recipe if you would like to do a chemistry experiment of your own!
