Wine Closures (2) - Long

"...The Wine/Enology-Grape Chemistry Group is currently evaluating the impact of accelerated aging, as a means of determining shelf life and differences among closures...".

Accelerated aging ???

Perhaps the article means the scam currently targeting wine drinkers. Maybe not.

There are some goddamn fools who have been told to believe that a magnetic field "accelerates" wine aging. Bogus devices are being sold to these damn fools, generally under the term "the wine clip." It is merely a magnet than clips onto a wine bottle. 30% of people will find the fraudulent device improves their wine: in other words, the placebo effect.

Yes, magnets are a scam, though I didn't read the above article close enough to identify it as a scam. Nonetheless, accelerated aging is really neat science,and actually we kinda use it in reverse when we age wines.

Accelerated aging is a standard way of testing materials to identify how they will age. You heat and store the materials for testing to a value below where they are known to fall apart (so, plastics, below where they soften or melt, metals below recrystallization temperatures, etc.). It's not exact, but a rule of thumb was that storing materials

10 degrees celsius warmer than the expected storage temperature will speed up the aging of the material by a factor of 2.

I used to be a medical device designer, and one of the things we would have to do was put an expiration date on our product, usually some set time following manufacture (1 year, 3 years, etc.). To do that, you had to test the product to show it still functioned following this time. Well, the only way to do that would be wait the time, do the test, then put your product out, but that meant that once you were done designing a product, you'd have to wait the expiration period until you could sell it, which means you'd probably have lost your market by the time you actually started selling. But with accelerated aging, you might be able to complete testing in 3-6 weeks for each year you wanted to have as an expiration date.

Having said all that, I'm not sure what they'd be testing for that wouldn't degrade with heat in wine. Perhaps they're looking at some chemical drop that would be at different rates in different closures, and accelerated aging would make the difference more obvious.

In wine-making and aging, we're using decelerated aging by keeping our wines below room temperature. We're giving the various chemicals in the wine more time to perform their magic without losing the flavor components.

Hope that explains it. I don't endorse the above, just explaining it.

Rob

Partying til dawn with strippers.....

If you really want some laughs, get a Physicians Desk Reference and look at the effects medications have on test patients. Then look at what a placebo does to another group who only =think= they're getting drugs. Man o man!!! ROTFLMAO!!!! People are amazing! Bob

Even easier, you know the ads for drugs in magazines? Usually on the next page, you'll see a small-print disclosure of all the information on the drug. About 60% of the way through the stugg, there'll be a table comparing side effects of people who use the drug against side effects of people using placebos. I tell you, reading those, I'd never take one of those placebo things - they'll kill you!

Rob

Who would have believed that the discussion of a perfectly serious serious article on winemaking processes (probably one of the more serious postings in quite some time) would have instantly deteriorated into a discussion of two misunderstood words and scams.

I suspect the wine industry is moveing to screw caps and short term they are probably right that they work just as well if not better than traditional corks. Most comercial wine is designed to be drunk within a year or two of bottling. A big question is whether wines that are really designed to be aged in bottle for a number of years are better or as good under a screw cap. If they had a reliable way of "accelerated aging" they may be able to determine this in a reasonable time period.

Another question is -- when is there going to be a reliable screw cap sealing system for the home winemaker. All the comercial devices that I have seen form the cap on the bottle. These devices are a bit pricey for home use.

Ray

Here's more on this topic:

"...Leigh Francis returned for another study presentation with "The Effect of Ascorbic Acid, Closure Type and Storage Conditions on the Composition and Sensory Properties of a Chardonnay and Riesling Wine." The study used unoaked riesling, and oaked chardonnay. Francis notes that ascorbic acid is used exclusively in white wine production, but cannot replace SO2 as a preservative; in Australia some studies have questioned the efficacy of ascorbic acid because visible browning was thought to correlate with ascorbic acid levels; this study wanted to verify if ascorbic acid was a problem. At bottling, both wines had 45 mg/ L ascorbic acid, with similar free SO2 levels. A spectrometer was developed which could measure light wavelength in bottled wines; the 420 nm wavelength is used to correlate with visible browning in wine and with low free SO2 levels. Storage also affects the 420 nm levels in chardonnay; upright storage increased levels for one of two natural corks used; synthetics used have more 420 nm levels than do natural corks.

Chardonnay with ascorbic added actually had less browning visible and with lower 420 nm levels. Ascorbic acid reduces the 420 nm levels when added at bottling; high 420 nm levels also correlates with oxidized aroma scores, but a single wavelength e.g. 420 nm is not as reliable as multi-wavelength levels for measuring wines with and without ascorbic acid measurement. The study conclusion was that ascorbic acid addition together with sound free SO2 levels at bottling contribute significantly to reducing 420 nm levels, or visible browning..."

This seems to contradict the earlier studies. Anyone ??