Peel off to the rose

from Wikipedia, the free encyclopedia
Peeled off to the rose, here while preparing the béarnaise sauce in a water bath

Peel off to the rose (also peel off to the rose and instead of peel off also pull / tie / knock off / boil off ) is a working technique from the art of cooking and means that a cream or sauce is bound , i.e. thickened, with the help of egg yolk . To do this, the liquid is heated slowly and evenly with constant movement until the temperature range of optimal binding and thus the desired thick-creamy consistency is reached.

Origin of the term

"Peel off" technically means " bind ". So that the mass heats up evenly and does not overheat on the hot bottom or edge of the mixing vessel, it is often recommended not to work with a mixing spoon or whisk , but to move the mass with a wooden spatula or dough scraper , continuously closing the bottom and the edge loosen ("remove").

The sample is traditionally done by taking some mass with a wooden spoon and blowing on it; If a wavy or ring-like pattern is formed, which is supposed to be reminiscent of a rose blossom , the desired consistency is achieved. However, this procedure should no longer be used in catering because it is unhygienic to blow on food, especially in the case of infections of the upper respiratory tract , such as coughs and runny nose. Instead, you can work with a thermometer.

In addition to this explanation of the "rose" - usually given in modern specialist literature - there is another interpretation, according to which a pattern remains on the surface of the mass with the appropriate consistency if the tip of a whisk is dipped in and then pulled out vertically.

Physico-chemical processes

The aim of peeling the rose is to use the egg yolk as a binding agent for thickening and - especially in butter sauces and other particularly fatty preparations - as an emulsifier. Egg yolks consist of about half water, 34% lipids and 16% proteins. It forms an emulsion of fat droplets in an aqueous protein solution, the droplets mainly occurring in two types: the greater part of the fat is in the form of micelles , small (⌀ 12–60 nm), typical lipoprotein structures with a core of neutral fat and a membrane from phospholipids with embedded proteins and cholesterol , which are known as LDL micelles ( low density lipoprotein ). The so-called livetins are dissolved directly in the plasma: water-soluble, long-chain, globular proteins folded in a tangle .

The Livetine are the least resistant to heat. When heating an egg yolk solution, they already begin to denature at approx. 65 ° C ; in the process, their peptide chains loosen and unfold and begin to connect with one another and form a network, in which case they stabilize air bubbles that have been struck. At the same time, they can increasingly accumulate water molecules and thereby bind water, the egg yolk begins to gel. The proteins in the LDL micelles are more stable, so the emulsion is retained. If the temperature is increased further, the LDL micelles are destroyed, the emulsion breaks, and the preparation becomes thinner again; If the temperature is increased even further, the mass becomes solid, the egg yolk coagulates and flocculates.

Viscosity η of an egg yolk solution as a function of temperature T. The arrow shows the “point of the rose”. (Figure based on Ternes, 2008)

The picture on the right shows the change in viscosity (thick liquid, designated with the Greek letter η ) of an egg yolk solution when heated. The "point of the rose" up to which the preparation should be tied is marked by an arrow; when pulling off to the rose, it is important to meet this first viscosity maximum. If the temperature were to be increased further, the viscosity would decrease again.

However, the diagram only shows one possible temperature range. The temperature at which the first maximum viscosity is actually reached in a specific recipe depends on the ingredients, for example the sugar and alcohol content , acidity and dilution of the egg yolk. Added sugar moves the “point of the rose” to higher temperature ranges, and added alcohol to lower ones. In general, the target temperature is above 65 ° C; for sweet creams it is stated that they have to be heated to over 80 ° C.

If you add fat to the preparation - like liquid butter when you make butter sauce - then the LDL micelles combine with the fat droplets, including the polar lipids that accumulate. The proteins of the LDL micelles unfold, rearrange the fat droplets, interact with the livetin network and thus stabilize the emulsion.

application

An egg yolk mixture peeled off to make a rose is the basis for numerous desserts, for example Bavarian cream , English cream (Crème Anglaise) or cream ice cream . Sauces that are peeled off to the rose may include: a. Dutch sauce (hollandaise sauce), béarnaise sauce , sauce mousseline and the classic with egg alloyed custard .

For desserts with milk, the egg yolk is first stirred with the sugar until frothy, the heated but no longer boiling milk is added, stirring constantly and slowly, and finally the entire mass is drawn off the rose, i.e. carefully heated until it thickens noticeably. Also Zabaglione is an egg yolk mixture, which is heated and thickened, but contains no milk and is beaten until fluffy in addition in a water bath.

A cream or sauce peeled off to make a rose must not be heated any further, otherwise the egg threatens to coagulate, the binding of the mass loosens again, and semolina-like lumps form. Therefore, a water bath is often used . This takes longer, but the energy supply can be better controlled and the mass cannot coagulate or even burn on the bottom of the pot as easily.

Individual evidence

  1. ↑ jonashaut: peel off to the rose - the secret of milk ice cream . In: gutengeschmack.wordpress.com. November 19, 2012, accessed August 18, 2015 .
  2. ^ F. Jürgen Herrmann: The great lexicon of dishes . Pfanneberg, Haan-Gruiten 2012, ISBN 978-3-8057-0513-4 , keyword rose peel off , p. 790 .
  3. ^ A b Günter Richter, Detlef Richter: Handbook of the kitchen. Professional working methods, organization, legal requirements . Matthaes, Stuttgart 2004, ISBN 3-87516-741-4 , p. 92-93 .
  4. ↑ Please, what does "pull off to the rose" mean? In: welt.de . February 17, 2007, accessed August 18, 2015 .
  5. ↑ Thomas Strixner, Ulrich Kulozik: Egg proteins . In: Glyn O. Phillips, Pete A. Williams (Eds.): Handbook of Food Proteins . Woodhead, Cambridge 2011, ISBN 978-0-85709-363-9 , pp. 168 ff . ( limited preview in Google Book Search - online edition).
  6. ^ A b c Waldemar Ternes: Scientific basics of food preparation . 3rd revised edition. Behr, Hamburg 2008, ISBN 978-3-89947-422-0 .