Essential Tips For Tirage

Putting the last thing first – is your blend balanced?

Judicious use of protein fining agents can remove excessive or coarse grape-derived phenolics. IOC’s animal free fining agents such as Inofine V (pea protein) can be used as early as juice fining stage and Fyneo (specific molecular weight yeast derived protein fraction) used as a final fine-tuning agent to give you the best balance. If there you need to shave off some excess oxidative browning in your base wines, No[Ox] is your friend.

Is your wine heat and cold stable?

Although protein composition is important to fineness of foam in sparkling, it’s a mistake to believe all proteins are beneficial. Fining to remove the more reactive, heat unstable plant proteins is necessary to avoid haze formation, gushing and wine loss at disgorging. Compact Due is useful at juice settling stage to maximise juice recovery when racking off juice solids and with the added benefit of removing some of the heat unstable plant proteins when used at juice settling rates. Inobent can be used after assemblage of your blend to confer heat stability at relatively low rates of addition.

Any tartrate crystals present in the wine can cause unexpected gushing when opened at disgorging or later as finished wine.

Even if your base wine blend components are cold stable prior to assemblage they may not be after – always check your assembled blend! Remember your final wine will be 1.3-1.5% higher in alcohol after secondary ferment – this can affect the solubility of organic salts; so add 1.5% ethanol to your cold stability sample before subjecting it to your nominated cold stability test.

To confer cold stability, you may choose temperature induced precipitation of potassium tartrate alongside a Cream of Tartar addition and agitation. If calcium levels are high, then delayed precipitation in bottle of Calcium Tartrate is a real risk and can be managed by the addition of microcrystalline Calcium Tartrate after potassium tartrate stabilisation to force calcium precipitation prior to tirage bottling.

Alternatively, CMC’s can inhibit further growth of crystals should they start to form. Inostab MES is a liquid form of CMC, and rates can be especially minimised if this addition follows some form of static cold stabilisation in the cellar. CMC’s can only be used if the wine is completely heat stable.

It’s a tough gig for the yeast to complete secondary fermentation without key parameters making life harder than it needs to be. Alcohol, free SO2, pH and dissolved CO2 or a combination of all these can affect the outcome. Consider any and all reasonable concessions to aid the yeast.

Since the yeast are essentially starting in finished wine, alcohol toxicity is already in play. During secondary fermentation alcohol will also increase by 1.3-1.5% alc/vol. Ensure alcohol levels are not too high in the initial blend. 11-11.5% alc/vol is recommended. Higher levels of alcohol may impact completion of secondary fermentation especially in sparkling reds as the phenolic content also impacts secondary fermentation.

Free SO2 strongly impacts yeast activity. De-sulphuring to lower free sulphur may be necessary. Recommended final concentration of free SO2 is 10ppm with a maximum of 15ppm. Pursuing lower free sulphur levels (<8ppm) may push into the error margin of sulphur analysis and increase the risk of chemically induced mousey taint formation if all free SO2 is exhausted – be wary.

Base wine blends of pH 3.0 to 3.2 are usual for sparkling wines. Excessive acidification or naturally low pH’s (<2.9 pH) can negatively impact yeast activity. Remember that low pH augments the percentage fraction of molecular (antimicrobial) sulphur in the wine.

Dissolved CO2 from primary fermentation can add to the impact on yeast. Estimates suggest that even low levels (0.4 g/L DCO2) can inhibit yeast activity. Sparging out any residual may help prevent the straw that broke the camels back scenario but remember that tirage yeast will need to ferment the sugar out to ~9.0 g/L DCO2 and to a pressure of 6 atmospheres.

The balance between alcohol, acidity, astringency and flavour is the cornerstone of high-quality wines with length and poise.

A suite of finishing tannins from IOC are available to fine tune the phenolic profile of your wine and draw out a fine, elegant finish in conjunction with the inherent acidity, alcohol and flavour.

Of particular use in this respect are Essential Antioxidant, Tannin Cristallin & Tannin CAS. All will contribute to freshness and finesse of the wine during tirage bottle age and fine palate length without bitterness.

Removal of all soluble solids or colloids by filtration is desirable (unless you are making a Pet Nat!) as this will mean the only thing you need to accumulate and remove at disgorging is the secondary fermentation yeast themselves.

If residual malic acid is present in the final blend, then sterile filtration is imperative to avoid MLF in the tirage bottle and associated difficulties in riddling.

Good yeast culture preparation is essential to successful secondary fermentation. IOC’s protocol outlines the steps designed to give you the greatest chance of success.

Yeast selection for secondary fermentation is critical and the best choice for high quality sparkling wines is IOC 18-2007. IOC 18-2007 keeps varietal character and terroir intact while adding autolytic complexity over time. Other yeasts suitable for secondary fermentation include EC1118 and IOC FIZZ+.

Stage 1 – Protection & rehydration of yeast:

As mentioned, alcohol and CO2 toxicity are real threats to successful fermentation. The best preventative is to employ yeast rehydration protectants from the Go-Ferm range. Both products have a high sterol content and will confer alcohol tolerance and CO2 resistance on the yeast.

Stage 2 – Acclimatisation to alcohol:

The initial alcohol of the yeast culture is lower than the final base wine blend. This will allow the yeast to build alcohol tolerance as they ferment and build cell numbers over time. First addition of Phosphates Titres – a yeast nutrient developed to build biomass in a relatively short growth phase – during this stage.

Stage 3 – Build active culture with high biomass:

Measurement of specific gravity (sugar) throughout is the basic measure that all is progressing as hoped in building a healthy yeast population.

Cell counts daily is also desirable here. Calculating the percentage viability using a Methyl blue stain and cell vitality by counting and calculating the percentage budding are very useful tools to ensuring your yeast culture is at full strength for the job ahead.

Percentage viability:

  • >95% – very good
  • 90-95% – good
  • 85-90% – fair
  • <85% – poor

A viable cell count of 50-70 million cells/mL is ideal.

Percentage budding:

  • >15% – very good
  • 10-15% – good
  • 5-10% – fair
  • <5% – poor

Any sudden drop in percentage budding at any stage of the culture preparation or once in tirage would be of concern.

Clarifiant XL, IOC’s liquid riddling adjuvant made with pure bentonite, ensures swift and thorough sedimentation. Tailor dosage rates to match pre-bottling cell numbers for optimal riddling efficiency.

Through mixing of yeast and adjuvant throughout tirage bottling, it is essential to ensure homogeneity of yeast cell numbers to adjuvant rate ratio from start to finish.

The choice of secondary fermentation temperature can be influenced by the desired wine style and urgency of availability of the sparkling wine for the market. This is especially the case for Charmat wines or rapid to market traditional method wines.

  • Ensure the temperature difference between the yeast culture and base wine is no more than 10°C.
  • For effective and complete fermentation, the temperature must be at least 11°C.
  • 15°C is ideal for sustaining viability and survival conditions towards toxins
  • >18°C – effect of increased biomass and influence on adjuvant ratio and thus riddling and disgorging issues may arise.
  • Storage temperature will influence the successful completion of secondary ferment and the onset rate of autolysis.

To maximise the surface area of yeast to sugar in the wine matrix, store tirage bottles horizontally. This also aids in biochemical exchange between autolysing yeast and the wine matrix when aging over time.

To develop a protocol for this crucial phase and to craft the finest sparkling wines, count on Winequip. We’re here to help you tailor your tirage protocol to perfection – ensuring your sparkling wines shine.

Contact us: Kelly Healey – [email protected] | Yahn Simons – [email protected]

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