Emulsions from a Culinary Perspective: The Case of Hollandaise Sauce and its Derivates

Research output: Book/ReportPh.D. thesis

  • Guro Helgesdotter
Sauces are among our richest food products both in texture and flavor. They play key roles for the total sensory impression of dishes and can make the other elements less monotonous and more agreeable to eat. Hollandaise sauce is an example of a highly valued sauce in the French cuisine. It is characterized as a mother sauce in the French sauce system, and numerous sauces are derived from this sauce, such as béarnaise sauce and sauce mousseline. Hollandaise sauce has, in spite of its limited number of ingredients, a rather complex structure and can be characterized as a mixed colloidal system, because of its emulsion, foam and suspension properties.

This thesis explores the structure and parameters influencing product diversity in
hollandaise sauce and similar products from a culinary point of view. It can therefore be regarded as an investigation in the field of molecular gastronomy. When consulting the culinary literature and culinary professionals, it became evident that large variations existed both in the preparation techniques and regarding the ingredients used in hollandaise sauce. It was unlikely that all these variations could lead to sauces having the same sensory properties.

The first step of the study consisted of exploring how classic preparation methods influence hollandaise sauce texture and flavor, and the results are presented in Paper I. The results showed that preparation techniques significantly influenced sauce properties such as texture and appearance, but only minor differences were observed among the flavor qualities. It also became apparent that an important development in hollandaise sauce texture has taken place the past 150 years. Accordingly, chefs have altered the preparation method of the sauce in order to obtain different textures. Today hollandaise sauces should, according to the chefs, be «airy, creamy and thick», while older recipes often yield denser sauce textures.

A central question regarding the hollandaise sauce ingredients is how the composition of the aqueous phase influences the sensory properties of the sauce. Wine reductions are commonly used in hollandaise sauce today, and the first part of the study aimed at understanding the changes induced by the reduction process. Four wines were selected and reduced, and their volatile profiles and sensory properties compared in Paper II. The reduction process caused numerous changes in the aroma profile of the wine reductions, and the wine reductions were also significantly different from the wines regarding basic tastes properties. People may believe that wines are reduced to «concentrate» the flavor, but this study illustrates the numerous and complex changes produced by the reduction process, resulting in reformulations of the aroma and basic taste profiles.

The wines and corresponding wine reductions were further incorporated into
hollandaise sauce, and the sauce composition and sensory qualities were explored. The results from this study are presented in Paper III, and show that wine and wine reduction sauces were significantly different, which means that the aqueous phase of hollandaise sauce significantly influences sauce flavor, albeit its minor contribution to total sauce weight. Furthermore, the butter in the sauce plays several modulating roles concerning the sauce flavor, as it retains aroma compounds and influences the perception of basic tastes.

This project was performed in close cooperation with chefs, and they were
encouraged to contribute with observations obtained during years of making
hollandaise sauce (and their derivatives). The chefs reported that the addition point of table salt and lemon juice to the sauce could result in different sauce textures. Egg yolk is a key ingredient in hollandaise sauce, as it plays several roles in the sauce. Saltand lemon juice are often only regarded as flavor agents in the sauce, but they are ingredients that may influence egg yolk functionality in hollandaise sauce. A preliminary study into the chefs’ claims regarding the addition points of salt and lemon juice was performed, and results presented in Paper IV. The findings partly supported the chefs’ observations by showing that the addition point of salt significantly influences hollandaise sauce texture. Hollandaise sauce structure and the influence of preparation methods and ingredients on sauce properties are further explored in this thesis.

This project was performed with a focus on molecular gastronomy, and the project was carried out in close cooperation with chefs. This collaboration influenced the research aims and topics, and hollandaise sauce was chosen as the research subject in this PhD to gain knowledge about how the culinary variation regarding hollandaise sauce production influences the product. This knowledge may benefit chefs in their daily work and may stimulate culinary innovation. The results also have several industrial applications.

In addition to the thesis and research papers, findings from this PhD project are also presented in two popular science articles (Article I and II). These articles are
intended for chefs and the public, as the scientific language used in research papers may represent a barrier for dissemination of knowledge from scientific fields.

This culinary approach to food research contrasts with the focus of traditional food science. The aim in this field is to gain more knowledge about the processes behind non-industrial food production, which is the cooking and food preparation taking place is homes and restaurant kitchens. Due to the complex nature of foods and human taste perception, interdisciplinary collaboration research projects are highly valuable in order to broaden our knowledge in these fields.
Original languageEnglish
PublisherDepartment of Food Science, Faculty of Science, University of Copenhagen
Number of pages220
Publication statusPublished - 2014

ID: 129663125