Egg whites are made up of water, protein, and small amounts of minerals and sugars see egg protein composition.. When eggs are beaten, air is added and the proteins are denatured exposing their hydrophobic water hating and hydrophilic water loving ends of the protein.
The proteins align themselves between air and water forming bubbles with their hydrophilic chains pointing into the water and dangling their hydrophobic chains in the air. In addition the proteins can bond to one another side-to-side as crosslinks which add to the stability of a foam. This makes it take longer to form the foam, but leads to a much more stable foam. If the foam is overbeaten in a non-copper bowl, eventually the proteins become completely denatured and coagulate into clumps. These clumps cannot be turned back to smooth peaks.
If a copper bowl is used, fewer protein molecules are free to denature and coagulate, because of the conalbumin-copper complexes. In addition to forming complexes with conalbumin, the copper may also react with sulfur-containing groups on other proteins, further stabilizing the egg white foam.
This has the effect of stabilizing the foam, and is therefore an alternative to using a copper bowl. The difference though is unlike proteins, fats don't bond to each other side-to-side to form a reinforcing networks instead they will compete with protein molecules in forming bonds. So, the addition of any fat e. Note: Once the protein complex is formed though it is safe to expose fat molecules to it.
As in the case of egg white foams it is the protein molecules that are responsible for milk being able to be foamed. And, as in the case of egg whites addition of fat will minimize the formation of foam. At this point highly stable cream type foams form. Both proteins are stable up to approximately F after which they become susceptible to denaturation.
At this temperature new proteins are needed for stable foam so more milk must be added. Low fat milk foams best at low temperatures. This also applies to both whole milk and cream, although to a lesser extent. In this case you already know what happens - the egg whites become very liquid.
A typical example are whipped egg whites first picture. To stabilize them you can add some foaming agent and here I want to give you a tip on how to use the whipped egg whites for decoration: Place 2 egg whites in a bowl and whip them until they are completely dense - turn the bowl upside down and the egg whites shouldn't move. Then add a tablespoon of powder sugar and slowly mix it in by hand. Use cake decorating set, fill the tube and use this mixture to decorate cakes and cookies.
The mixture will harden quite fast. In the second picture you can see a decorated gingerbread heart. In the last picture you can see again some parsley foam, this time made with gelatin.
I used 2 teaspoons of gelatin powder for g of mixture because I wanted my foam to be very dense but you can use lower ratio or just follow the instructions on the package. How to make it: Boil about ml of water with 2tsp of gelatin powder.
Switch off the stove and add a handful of parsley. Blend all well and let the mixture cool down. When it's completely cool, it shouldn't be liquid anymore. Now take an electrical whisk and whip it very fast.
Maybe the Pavlova cake comes to your mind. A meringue is made from whipped egg whites combined with sugar and sometimes other ingredients, and baked.
How to make a simple meringue: Whisk 2 egg whites like in the previous step and then slowly mix in a tablespoon of powder sugar. Whipping siphon, 1 L. N2O cartridges. Mix with an immersion blender, and then pour into a cold one-liter whipping siphon. Shake well. Test the foam for consistency. It should have a velvety appearance but be too soft to hold a peak.
If the foam dissipates too quickly, charge the siphon a second time. How to cook pork rack sous vide. How to cook duck breast sous vide. How to cook apricots sous vide. You may also like. How to make a brine. How to set up a barbecue. How to smoke using a barbecue. The ultimate gothic menu for Halloween. How to make kefir.
0コメント