"O, for a draught of vintage! that hath been cooled a long age in the deep-delved earth"

John Keats

In this chapter we follow the fruit into the winery and the main subjects concerning preparing it for fermentation are discussed. This is one of the longer chapters in the book as white and red wines require quite different approaches and techniques.

I encourage you, once again to take the time to read the footnotes despite the cumbersome way that Substack forces them into an endnote position - which is annoying!

I believe that with this chapter in particular the reward will compensate you for the trouble.

Chapter 16. Fruit Processing

Pressing white wine or rosé

White grapes should go to the press as soon after picking as practical, and as cool as possible. Colder fruit allows a more controlled extraction of the juice. White grapes press better if the fruit is loaded into the press as whole clusters. This is not possible with machine harvested fruit, so a press aid such as rice hulls may need to be added. The best practice for white pressing is to use a Champagne-type press cycle. This protocol uses multiple low-pressure cycles with minimal rotation of the press—requiring roughly twice as much time as a typical white wine press cycle. Adequate press capacity must be factored in to employ it regularly. A static press—such as a basket press—is also quite gentle, but little used outside of Champagne. The ideal is to extract most of the juice at very low pressures.

As the Champenois have found, the quality of the wine is improved if press cuts are made. For practical purposes, most whites can be separated into two portions, a light press and a heavy press. Depending on varietal and style, the light press cut should be made between 130 and 140 gallons per ton. Because the level of sugar masks most other flavors, it is almost impossible to determine by taste when to make this press cut. So, experimentation with your own fruit is the best method. A portable pH meter deployed at the press pan can be an effective tool. In some cases, an abrupt upward shift in pH occurs as potassium begins to be extracted from the skin. This can indicate that other undesirable elements are also being extracted from the skin. The light press portion tends to make lighter colored wines with greater finesse and enhanced flavor stability in the bottle.

Even if you intend to eventually blend the heavy press back into the wine, it is a better practice to handle it separately until such time. The heavy press juice will have a higher pH and more phenolic compounds—conditions that usually need to be addressed before the juice or wine’s inclusion in the blend. It is especially important to make these press cuts with wines such as Chardonnay and Riesling, which are known to be high in yellow pigments.[1] Any white fruit that has seen significant exposure to direct sunlight and shows yellow-to-brown pigments in the skin ought to be handled this way. Varietals known to be high in phenolic compounds, such as Pinot Gris and Gewürztraminer, should also be made using press cuts.

The hard-press portion of the juice will normally receive some sort of fining immediately to lower phenol and color content. It will usually need an acid addition to control the higher pH caused by the extraction of potassium from the skins. The hard-pressed juice should be fermented and stored separately, until it can be determined whether this juice is of comparable quality to the lighter press. Several months may be needed before this determination can made. In most cases, the quality of the hard press wine is lower, and not appropriate for use in fine wine.