In February the weather conditions and cold temperatures allow the winemaker to split his time between vineyard and cellar activity, writes Dr Ariff Jamal, continuing his German vineyard series. Having pruned the vines in preparation for a period of vegetating in January, he now finds his way back to the dark, gloomy cellars to tend to the fermented young wines. The wines need to be stabilized and made free from adverse colloids, failing which, there could be an unfavorable second fermentation.
Start fast, and then slow down – the wines need to be “racked”.
The first racking normally takes place soon after the alcoholic fermentation. The suspended solids, which consist of dead yeast, bacteria, tartar crystals and the remaining pulp cells, have now settled down on the bottom of the tank or barrel due to natural gravity forces, leaving behind a cloudy juice. The act of racking separates the juice from these sediments, transferring it to another tank or barrel leaving the deposits behind untouched.
This hazy juice now needs to be clarified. The aim is to retain all its primary fruity and floral aromas, so the winemaker commences the process of stabilization. This can be carried out through two methods, one, by the use of chemicals and the other, the natural method, by means of cold temperatures which help preserve all the virtues of the flavours originating from the grape. In the process of cooling down the wine, the excess tartaric acid, over time, is precipitated into crystals which gradually settle down to the bottom of the tank.
Herbal, spicy and mineral aromas are considered secondary and the winemaker’s task is to seek these out and at the same time clarify his wine. The small particles which remain after the first racking along with fine yeast which has settled to the bottom of the tank or barrel create a “lie” allowing for the development of a balanced, full-bodied flavour in the finished wine. At this stage the wine extracts the last ascendancy from the yeasts to build itself into a stable and long lasting structure, which permit the young wine great storage and aging potential.
To obtain tertiary aromas – mainly dry fruit and animal – the wine is stored either in wooden barrels or in stainless steel tanks. Wooden barrels, no matter what size, toasted or not, have fine pores allowing for a steady exchange of oxygen. This helps develop aromas of a riper and maturer character, well-rounded and more complex. The stainless steel tank does not allow for this oxygen exchange – and thus the wine appears young and fresh.
The second and final racking terminates this course of action. The separation of the wine from the finest suspended solids is done with the help of fine membrane filtration. The wine is now totally clear – full of aromas, free of colloids and totally stable for bottling and storage.
In February, the days in the Mosel valley grow longer again and the deep gloomy cellars become brighter – with an end to turbidity, the wines and the winemaker’s achievements become clear and the long winter wait gradually comes to an end, bringing with it a promising new wine and the splendour of a new vintage.