Cellaring is about ageing a fermented young wine until it is mature and, hopefully, drinkable. We cellar the wine in oak barrels for 2-3 years, then bottle it and then store the bottles for another 2-5 years until they can start to be consumed. In other words, we start drinking our wine 4-7 years after the grapes were harvested and we expect it to improve quality for another 5-15 years after that. This means we only find out 10 years after harvest and winemaking whether we did a good job (we find out much faster when we do a lousy job!) – thus the need to keep good records, and the slow learning process. This also translates our annual production of 2 barrels into a required cellaring capacity of 8 barrels and over 5,000 bottles (more than we originally anticipated).
Cellaring comprises 5 interlinked activities:
- ML: Initiating and watching for completion of the Malolactic Fermentation
- Elevage: Ageing wine in barrels or tanks takes 1-4 years. During this time the barrels need to be topped up every 4-6 weeks to compensate for evaporation, sulfur needs to be replenished to prevent contamination and adjustments are made if required.
- Adjustments - there are 4 basic types of adjustments: Filtering, Fining, Cold Stabilization and Racking & Blending.
- Bottling & Maturation: Before bottling, the wine in the mixing tank needs final adjustments in SO2 (to prevent spoilage) and possibly in CO2 (to compensate for too much or too little aeration during winemaking and cellaring). Then the wine is poured into bottles, the bottles are corked, capped and labelled, and finally, the wine is aged in the bottles for another 2-4 years before it is ready for consumption.
- Barrel/Tank Management is about selecting and buying barrels and tanks, about cleaning them after use (i.e. following a Racking operation) and about storing unused barrels until they are needed again.
This section is organised into the following 10 pages:
- Barrel & Tank Management: How we select tanks and barrels, how we keep them in good shape and how long we use them.
- Malolactic Fermentation: This page describes how we initiate and monitor the progress and completion of the Malolactic Fermentation in the cellar.
- Elevage: We monitor how the wine ages in the barrels or tanks, how we top up the barrels because water in wine evaporates through the wood and how we replenish the sulfur content to prevent contamination. Every 4-6 weeks when we check, we have the opportunity to make adjustments: Filtering, Fining, Cold Stabilization, Racking & Blending as explained in the following pages. Ageing is complete when the wine is judged ready for bottling.
- Fining: We can remove specific chemical substances in the wine by adding specific fining agents which bind to these substances and aggregate into very large molecules which precipitate into sediment and can then be removed by Racking
- Filtering: We can filter the wine conventionally to remove large particles, or we can process it through a reverse osmosis filter to remove only the smallest particles.
- Cold Stabilization: We can remove certain chemical substances by cooling down the wine to just above 30 dF. Keeping the wine at that temperature for a few days will make these chemicals crystallise and precipitate. Then we remove the sediment by Racking.
- Other Adjustments: This is a grab bag for dealing with other wine-faults
- Racking & Blending: Racking is syphoning out the wine from a barrel into a temporary holding tank, leaving the sediments behind. Then the sediments are removed, the barrel is cleaned, and the wine is poured back in. Racking can be followed by Blending. We can blend wine from different barrels or tanks to create more complex wines or to cover up wine faults which are only apparent in higher concentrations. To blend we rack wine from different tanks or barrels into a blending tank, mix and then pour the mixture back into clean barrels or tanks.
- Bottling & Labelling: Before we bottle we give the wine a final dose of SO2 and we check the dissolved CO2 level. For our wine we target a dissolved CO2 level of around 100-150 mg/L. Then we transfer the wine into bottles and cork and cap the bottles. Finally, we design and print bottle labels and affix them to the bottle
- Bottle Storage & Maturation: We store the bottles under temperature and humidity control for a few years until the wine is ready to drink
- Cellaring Summaries: a summary of how each vintage was treated in the cellar.
The graphic on the right illustrates the differences in the cellaring process across vintages 2009-2015. The height of each bar reflects the relative size (in lbs) of each harvest. Note, the number of bottles does not correlate well with the size of the harvest because we blended some vintages with purchased fruit (e.g. Merlot in 2012) or with wine from other vintages. The brown and the grey fields reflect the time allocated for barrel ageing and bottle ageing. Note, even after release for consumption, the wine in the bottles continues to improve for years until it reaches its peak value and after that, it slowly deteriorates. From harvest to peak value takes 8 to 15 years. The more tannic the wine, the longer it takes to reach its full potential.
The following graphic illustrates how the different vintages from 2009 to 2015 are linked across the elevages as top-up wines are used across vintages and as portions of wine from surplus years (e.g. 2012) are used later to compensate for shortages in years when the harvest was not big enough to fill one or two barrels. This tracking is essential for determining what the final composition of the wine is when it gets bottled each year. The graphic also shows what adjustments have been made to the wine during elevage.
Starting with the 2016 vintage, the process became more complicated. We fermented different varietals and blended them during cellaring. We needed to replace our data management in spreadsheets with a relational database. It will take some more time to develop comprehensive reports from data the new database describing the cellaring across vintages.