Preservative Free Overview
Many of us mistakenly accuse alcohol for our 'post alcoholic beverage' discomforts, not realizing that high levels of SO2 may be the primary culprit."
Sulphur Dioxide (SO2) is the principle preservative used in the production of wine. People's tolerance to it varies widely. It's like bee venom and many other irritants: your susceptibility increases with continued exposure. As you get older you're increasingly likely to notice its effects. You might start waking up in the middle of the night with a very itchy nose, or have asthmatic tightness, a cough or a headache. The bottom line is that while most people's bodies can survive without strong reactions to SO2, it is not good for anyone.
The legal maximum level of sulphur dioxide wine is 350 parts per million, a level that may be approached in some bulk product in non glass containers (cask wine). Containers that are permeable to oxygen have a short shelf life. Many other foods less inherently stable than wine depend upon sulphur dioxide as a preservative of colour and condition. Dried fruits and some cold stored fresh fruits are examples. Most large commercial wine manufacturers have highly mechanised production methodologies which require extensive use of sulphur dioxide in the production process. Hand picking and careful fruit management allows a more conservative approach.
The Happs preservative free range is the product of years of experience. In these wines we do not use sulphur dioxide at all. There are strong preservatives, naturally present. These include tannin, low pH and alcohol.
Many consumers are under the mistaken impression that if a wine does not contain 'preservative' it has a very short shelf life. My experience is that the life of wines after bottling can be related directly to the quality of the fruit, the care with which these wines are made, the degree of oxidation allowed in processing and in particular bottling, and the wines content of alcohol, acid and tannin. Our experience suggests that wine with abundant natural preservative will last as long as any wine containing so called 'preservatives' by addition.
How long? Five years minimum. After five years there should be little difference in 'added preservative' levels, between wines that initially had, and those which never had, sulphites added. This is particularly the case with reds because the colour binds up the sulphite anyway. It's a level playing field from that time on.
Then there is the question of oxidation after bottling. To play it especially safe, we've chosen to use screw caps on our PF wines to eliminate that possibility.
There is nothing that has taught me more about winemaking than the effort to make wines free of sulphur dioxide. I reckon that the production of one preservative-free wine should be mandatory for all winemakers. The capacity to produce a high quality PF wine tells a story about ones technique.
Our first PF Red was made in 1994. The grape mix changes a little each year. We are planting vines specifically for this wine, namely tempranillo, grenache and pinot noir.
This is frontier stuff. There are very few producers making preservative free wines. There are many more trying to be organic in the vineyard than there are trying to be natural in the winery. It's all part of the rich texture. For my money, the latter is the more direct approach to reducing the use of what might be called 'doubtful chemical' inputs
The commonly used form of sulphite used in wine is potassium metabisulphite.
Our dry reds in both the Happs and the Three Hills range, all of which are given wood maturation for a year and then bottle maturation for a further year, have very low levels of sulphite at release. They easily meet the requirement set for European Organic wines (i.e. below 20 parts per million free sulphite).
Our pink and the white wines are released with total preservative levels between fifty and ninety parts per million and free sulphite at between ten and thirty parts per million. These levels decline with time. These wines do not possess the tannins which protect dry red wines and more sulphite is necessary as a defence against oxidation.
Pale Gold commonly requires about one hundred parts per million sulphite added to bind up some compounds which come in fortifying spirit. Again, free sulphite levels drop with bottle aging.Wine Preservatives Kill Beethoven!
I have learned (cant quote chapter and verse) that what killed Beethoven (1770 - 1827) was the lead in the wine that he drank. Being a sickly fellow, and having to endure much pain, it was his custom to drink a couple of bottles of wine every day. The wine had lead in it, the water pipes and the roof had lots of lead and so did the drinking vessels of lead glazed pottery and lead fluxed glass.
The use of lead in wine predates the use of sulphur dioxide. The practice was common amongst pre Christian Romans. We are told that lead much improved the taste of wine giving it a softer fuller flavour. I don't know whether lead has antibacterial properties but would not be at all surprised if it did. Many compounds that might induce nothing worse in humans than bronchial discomfort, a nasal snort or a slight headache can be fatal to bacteria and insect life.
In Beethoven's time, fermentation was a complete mystery. Modern winemaking owes much to Louis Pasteur who drew aside the veil on yeast and bacteria in 1866. Unfortunately, it was just a bit late for Beethoven.