The oenological practice of must clarification, as a preventive treatment in wine making, takes on fundamental importance in order to proceed with fermentation that will result in wines with better organoleptic and taste characteristics.
There are several procedures for clarifying musts: static settling, centrifugation, vacuum filtration and flotation. The latter represents one of the latest innovations in the field of separation technologies. A system borrowed from other industries, and which has found convenient use in oenology since the early 1990s because of its particular speed and effectiveness in the clarification process.
During the flotation process, excellent solids separation is achieved in a short time and at high efficiency, maintaining high levels of hygiene in the winery practice.
If you want to produce a wine that stands out from the crowd, you need to learn more about how this process works and why it is so important. Having ascertained the importance of the flotation process let us proceed with insights in detail; pwe will talk about what flotation is, why it is important and how to use it to produce your wine. In no time you will become an expert on the flotation process!
The fundamentals of flotation
When it comes to producing wines of high level and excellent stability, the old saying “the devil is in the details” turns out to be as appropriate as ever, and the detail that can make the difference in winemaking and precisely the flotation.
But what exactly is it? … and why is it so important for winemaking?
Flotation, also known as clarification, is used to remove solid particles such as trub and skin pulp from the grape must. It is a process that produces a clear product in a very short period of time. Generally used for clarification of white and rosé wines, also used with excellent results for red wines.
Let’s get more clarity…
Flotation is an enological practice designed to clarify the must and separate residual skin and peptide material, thereby also removing the lees and phenolic components from the juice. It is an extremely efficient process that is based on the separation of suspended solids into the liquid by introducing microbubbles of gas (such as nitrogen, air, oxygen or argon) that adhere to the suspended solids, decreasing their density and bringing them to the surface.
This process takes place prior to alcoholic fermentation by means of a machine called a Floater. This consists of a pump to put the liquid under pressure, mixing it with the chosen gas. This results in separation, where, on the surface will be the captured solids that will form a more or less dense foam to be removed later, and at the bottom the clear liquid.
Being a chemical-physical process, flotation is influenced by several parameters. First, it is necessary that the must be at a temperature of not less than 12°C and not more than 20°C so as to ensure proper density of the wine. Second, it is necessary for the polypeptide chains to be small enough so that they adhere properly to the gas bubbles that you are inserted.
In addition, depending on the characteristics of the grape and the vintage, other types of adjuvants may be added such as:
- PVPP (Polyvinylpolypyrrolidone) to remove oxidized compounds and to make taste and odor cleaner;
- Bentonite to eliminate oxidative enzymes and avoid fermentation problems;
- Gelatin to compact the lees and have a clearer must.
This process can greatly decrease the time required for clarification and help minimize the risk of oxidation, allowing for a fine, better-tasting product with minimal effort.
Bibliography
1. Assoenologi: “Flottazione”, parole del vino, https://www.assoenologi.it/enologonlinerubriche/flottazione/
2. Emanuela Ferrari: “Illimpidimento per flottazione dei mosti bianchi di prosecco e friulano con l’impiago di proteina vegetale da patata a confronto con gelatina animale”. Università degli studi di Pavia, 2013/2014.
3. Zeynep Kollu: “Ottimizzazione della flottazione in continuo: esperienze applicative…”. Università degli studi di Pavia, 2012.
4. Enologonline.com : “Flottazione”, https://www.enologonline.com/flottazione/
