Whilst the usage of egg whites as a tool for texture manipulation is well known and necessary in a venue that features classic cocktails, the substitution of animal products for other substances is global development. So far, most bars are still using egg whites in order to create a rich and frothy texture that enhances a cocktail. Several alternatives exist each with varying benefits.
Two [1,2] Punch articles provided us with information as well as a possible approach.
Although we had positive experience from earlier experimentation with Aquafaba an alternative approach was needed due to a lack of other usage for chickpeas. Our intention was also to create a base recipe that can be hacked and varied by anybody. Gum Arabic and Methylcellulose were chosen for their shelf stability, availability and relatively low cost.
Gum Arabic, being of natural origin, can vary in its composition of poly sugars and proteins attached to sugars thus potentially influencing its ability to create a frothy structure. The Wikipedia article on gum Arabic  provides more insights into its origin and usage.
Methylcellulose is a polymer that is based on cellulose and a common food additive. It is probably most know for its ability to solidify emulsions at temperatures above 60°C and has been featured as the key ingredient for “Magic Noodles” in Modernist Cuisine. Varying forms with varying properties of Methylcellulose are available for purchase. A good overview is available via Modernist Pantry .
Methylcellulose was purchased from Würzteufel and Gum Arabic from Amazon.
We created a combined solution of Methylcellulose and Gum Arabic by dissolving the combined powders (each 1% by weight) in boiling water.
Even though it is gelling at higher temperatures it was easier for us to dissolve Methyl Cellulose in the boiling water than at room temperature. A possible explanation can be found on Wikipedia .
In order to determine the gelling and binding properties of our solution we tested a Whisky Sour with traditional egg white as well as our hydrocolloid mixture. In order to pour a constant stream of egg whites organic eggs were separated and the whites were slightly shaken.
We compared the same base recipe for a Whiskey Sour with 20 ml of the pre-shaken egg white and 20 ml of our hydrocolloid solution. Both Sours we shaken on ice first, thrown and then dry shaken.
RESULTS AND DISCUSSIOn.
Thick and stable foams can be produced using the hydrocolloid solution. The stability of the hydrocolloid sour over time was comparable with the traditional cocktail. Both cocktails had notable foam after 15 min.
The overall flavor of the Whiskey Sour with egg white was distinguishably better and well rounded. The gum Arabic and Methylcellulose solution doesn’t add any flavors in particular, however it fails to bind and blend the flavors of the cocktail in a manner in which egg white does. It could be argued though that the abilities of the fresh egg white are only present if the organic egg is used a la minute which is not always the case in bars.
Cost calculation yields an approximate cost of 0,013 € per serve thus being extremely cost efficient.