PVPP: USE AND CHALLENGES
The soaring cost of raw materials – particularly PVPP – as well as their origin are currently a topic of debate, and it is now necessary to think of possible alternatives. Whether for must or for wine, fining with PVPP can have several oenological goals – to control colour parameters, to prevent or treat oxidation phenomena, or for organoleptic improvement.
MARTIN VIALATTE® has a long history of expertise in the development of fining. Since the late 1970s, our teams have been developing innovative products that meet the technical objectives of fining and the regulatory, economic and logistical constraints of wineries.
FINING DECISION SUPPORT
Selecting the right fining agent is a matter of goal and choice. The characteristics of each matrix, as well as the goals and constraints of the winemaking process, guide the fining decision. Whether for oenological, regulatory or economic reasons, thinking through the fining process is an important step in the winemaking process.
PREVENTING WINE OXIDATION
Handling the oxidation of must and wine is a major issue for winemakers. With musts, enzymatic biochemical reactions are involved – phenolic acids, which are the polyphenols most sensitive to oxidation, are transformed into quinones. These mechanisms can be detrimental to the wine’s aromatic potential and longevity. In fact, quinones will react with flavonoids to form heavier and heavier complexes, leading to brown case and induce the loss of natural glutathione in wine by forming GRP2 complexes that precipitate (glutathione – phenolic acid interactions). Vegetal protein-based solutions such as PROVGREEN® PURE MUST enable the removal of oxidized polyphenols (quinones) and easily oxidizable polyphenols (phenolic acids), thus preventing premature oxidation of the must.
MASTERING WINE COLOR
One of the goals of fining can be to adjust the colour of the musts that are obtained after the first steps of the vinification process (crushing, pressing, maceration, etc.). This correction of the colour may also be necessary if the must or wine is oxidized. Fining agents can impact colour in different ways – some have more impact on red, others on yellow. One last category is more versatile, since it affects both yellow and red colours.
PVPP is effective for adjusting red colouring in rosé wines. It can be replaced by PVP/PVI-based solutions such as ORIGIN FRESH. Plant protein-based solutions such as PROVGREEN® PURE MUST are the most effective in reducing yellow colouring.
PRESERVING AND IMPROVING WINE AROMAS
Eliminating bitterness and vegetal aromas, enhancing the aromatic palette or varietal characteristics, imparting finesse or length – these are all organoleptic goals that winemakers can aim for and achieve by fining. Again, choosing and thinking through any addition is essential in order to preserve and improve the aromatic qualities of the wines. PVPP, which is used to reduce bitterness, can result in a hollow midpalate or a loss of fruitiness. There are other products that are more wine-friendly. Each fining product in the MARTIN VIALATTE® range has its own “organoleptic signature”.
KTS® FLOT: A TOOL THAT ADDRESSES THE MULTIPLE CHALLENGES OF MUST FINING
MARTIN VIALATTE® best-seller KTS® FLOT is an unbeatable ally for flotation and static clarification (Figure 1): even at a low dosage, it guarantees fast, optimum settling of the lees. Due to its versatility, KTS® FLOT is also an excellent tool for preventing oxidation, mastering the colour and correcting bitterness.
The tests carried out by our teams in the field in recent years with the NOMASense™ PolyScan tool, from our partner WQS by VINVENTIONS, have enabled us to accurately characterise the products in the MARTIN VIALATTE® range and to establish KTS® FLOT as an effective alternative to animal-based products and to PVPP.
Figure 1: Tracking static turbidity as a function of time in white musts treated with the same dose (7.5 cl/hl) of different liquid fining agents.