In Ageing

The Architect: You played a very dangerous game.

The Oracle: Change always is.

I was fortunate enough to visit Chateau Quinalt in St.Emilion a few years ago. Now the essence of this blog is to look at alternative ways to manage lees, and not to gossip about how and why this Chateau became a “Parker Darling”, but the truth is that their Parker ratings became quite significant. And I must say, I love everything I have tasted. I was also fortunate enough to spend a bit of time in the cellar.

This is where I saw the technique of taking healthy lees and keeping it in suspension at above 350C for a substantial amount of time with a slow mixer, and using this autolyzed broth to top up the barrels…or at least this is what they have told me! The red lights started flickering, and I immediately thought to myself: “Lees, autolysis, food for bacteria, VA and finally- spoiled wine”. So I was extremely happy to meet Michael Paetzold in the early 2000’s and the technique which they refer to as Thermoflash®. This is a heat treatment process for musts and wines, based on the principles of flash pasteurization, by subjecting the product to a specific temperature for a set period of time. The treatment is ideal for the preventive or curative management of the microbes in wines. It can be applied during different stages of the winemaking process and even on different types of wines. The difference between pasteurization and flash pasteurization is heating the wine to 60-70°C for 1 to 2 minutes, vs. heating the wine to 71.5 to 74°C for 15 to 30 seconds. This shorter period, slightly more intense treatment of the wine is effective in destroying acetic acid bacteria and lactic acid bacteria, as well as Brettanomyces, while maintaining the organoleptic qualities of the product.

The nett result? Wines that can mature healthy in contact with lees until the, let’s say “mouth feel readiness” has been achieved. I have worked with this technique the past few years with excellent results. This however is not going without saying that SO2 management remains a critical aspect in maturation management, but merely a tool with a lot of potential, in order to reach a stylistic goal.

The process of autolysis may be enhanced by the addition of glucanase enzymes. These enzymes are industrially prepared from Trichoderma fungus cultures and preferably added after fermentation. Its action takes from 7 to 10 days and must occur at a temperature equal to or greater than 10◦C. Higher doses are required in red winemaking simply because phenolic compounds partially inhibit the activity of the enzyme.

Practical advances (and significantly simpler) in the management of lees include barrel racks with wheels that facilitate rolling of barrels in order to get the lees into the suspension without opening the bung hole and having to stir the lees with a putter (battonage). The Oxo trademark is the “designer’s folly” as to how to achieve this, but exactly the same can be achieved by rolling the barrels on the parallel floor stands (if of course it’s not stacked).

Different strokes for different blokes I suppose…the essence of the blog is to say that to roll or not to roll, to flush or not to flush, changing your ways to adopt some sound lees management practices will benefit your wines.

Bertus Fourie is a winemaker, turned Enology lecturer and creator of the Barista coffee Pinotage.

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