Scott Labs Fining and Stability Choosing Guide
Applies to: Winemakers looking for assistance in selecting and comparing Scott Labs fining and stability products. This guide contains a downloadable pdf choosing chart that characterizes our fining and stability products by winemaking stage and intended impact.Download
Selecting Fining and Stability Products for Success
Fining and stabilizing are complementary actions that remediate and protect juice and wine from off-odors, off-colors, and unsightly hazes and precipitates. Fining removes unwanted elements from juice and wine by physical removal. Though fining agents work by different mechanisms, they all react with or adsorb unwanted substances that are then removed by racking, filtration, centrifugation, or other means. Stabilizers react with substances to prevent wine hazes and precipitates from occuring. A properly fined, stabilized and filtered wine ultimately leads to a bottle-stable wine.
To properly select appropriate fining and stabilizing agents many considerations must be taken into account. First identify the fining or stability goal and then choose a treatment appropriate for the stage of winemaking. Early, proactive treatments are always recommended. Treating problems early can avoid compounded problems later.
What can be addressed by Fining and Stabilization?
Browning & Oxidation
Grape juice and wine can oxidize leading to unwanted visual, sensory, and chemical changes. Conditions leading to browning and oxidation are not always understood, but treating problems early is always encouraged. Early fining with activated carbon and PVPP/Casein based products can help remove oxidized phenolics and brown pigments in both the juice and wine phase.
High solids can be problematic. Solids removal can be achieved using enzymes, gelatins, PVPP, bentonite, and casein. These options can be used pre- and post-fermentation. Post-fermentation isinglass can be used to reduce turbidity due to polysaccharides and colloids thereby eliminating multiple filtration steps.
Haze can be caused by many things: microbes, heat unstable proteins, tartrates, residual fining aids, etc. Protein instability can be remedied by using bentonite and residual fining aids can be removed by Cristalline Plus and silica gels like Gelocolle. Microbial hazes can be reduced via fining and filtration. Microbial stability can also be achieved through appropriate use of microbial control agents.
Preventing tartrate precipitation in a finished wine can be achieved in a number of ways. Traditionally, tanks are seeded with potassium bitartrate and chilled close to freezing temperatures to induce tartrate precipitation before bottling. Recent advances include adding tartrate inhibitors like mannoproteins and gum arabic. These products work by inhibiting tartrate crystal formation, thereby keeping tartrates in solution.
Wines with perceived astringency and bitterness may be improved with the use of gelatins or other protein-based products that complex with polyphenols. When the goal is to improve aromatic profiles, products like isinglass, tannins, as well as gelatins are useful.