Weighing in..

Anything to do with Port.
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uncle tom
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Weighing in..

Post by uncle tom » 18:58 Sat 24 May 2014

For a long time I had it in mind to start weighing bottles as part of my routine record keeping, but it remained a 'round tuit' until last year.

Now I wish I'd done it a long time ago..

The driving purpose of periodic weighing was to identify bottles that were ullaging faster than others, and flag them for early consumption.

Since I started doing this though, I have discovered that most batches of bottles made over the last fifty years (but not all..) have very consistant dry weights, so that where the glass is too dark to ascertain the level, weighing helps flag up those that are more ullaged.

It is also interesting to establish how fast sound old bottles lose fluid.

To put a perspective on things, a bottle that has ullaged from a typical IN level down to VTS will have lost approximately 20g in weight, so a bottle that ullages to VTS over 40 years will be losing 0.5g per annum on average, although I suspect that in most cases this is an accelerating phenomenon.

The scales I bought for the purpose can weigh up to 2Kg with a resolution of 0.1g. To ensure consistency, I check the scales with a reference weight (a sealed bottle filled with marbles to a weight of approx 1350g) each time I do a weighing session. In practical terms, my readings will be about +/-0.1g accuracy.

So far, early re-weighs of old bottles have often produced matching weights, and my first trial weighing of some N63s with foil capsules (Berry bottled) has shown a loss of just 0.1g over 18 months.

Although most bottles have consistant dry weights, there have been one or two surprises. One case of T83 had very consistant levels, but with one bottle (visually identical to the others) that was 25g heavier.

It will be interesting to see how the results pan out over time.
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill

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DRT
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Re: Weighing in..

Post by DRT » 19:07 Sat 24 May 2014

uncle tom wrote:One case of T83 had very consistant levels, but with one bottle (visually identical to the others) that was 25g heavier.
:shock:

The laws of the Universe dictate that some additional mass has been added to either the contents or the exterior of that bottle.

Was it particularly dusty when re-weighed?

Have some pesky creatures burrowed into the cork and made a home for their many offspring?

Has someone been in your cellar with a Vacuvin, removed some or all of the T83 from the bottle and replaced it with slightly more of something else?

Or did you perhaps make a mistake when you weighed it the first time?
"The first duty of Port is to be red"
Ernest H. Cockburn

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jdaw1
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Re: Weighing in..

Post by jdaw1 » 19:19 Sat 24 May 2014

A loss of 0.1g a year implies two centuries to drop to VTS. And as your measurement error is ±0.1g, that is effectively no loss. Very good.

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uncle tom
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Re: Weighing in..

Post by uncle tom » 19:45 Sat 24 May 2014

The laws of the Universe dictate that some additional mass has been added to either the contents or the exterior of that bottle.
This was on the original weighing, not a change in weight. I assume that Taylor had more than one production run of their 83 VP bottles, and the glass factory managed to make one batch a lot heavier than the other, with one stray bottle from the heavy batch finding it's way into my case. (The selo numbers were all from the same sequence though)
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill

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Re: Weighing in..

Post by DRT » 20:57 Sat 24 May 2014

Apologies, I read that as being a difference between the two weighings.

Given when it was it is possible that one glass bottle came from a different batch and was slightly thicker?
"The first duty of Port is to be red"
Ernest H. Cockburn

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uncle tom
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Re: Weighing in..

Post by uncle tom » 21:36 Sat 24 May 2014

Given when it was it is possible that one glass bottle came from a different batch and was slightly thicker?
The other bottles range from 1331.7g to 1340.6g, and are consistant with their visible levels. The odd bottle had a similar level to a bottle weighing 1336.3g but had a weight of 1363.3g

I thought at first that I had transposed two digits of the weight, but after double checking found that it was indeed an 'odd' bottle..
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill

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Re: Weighing in..

Post by uncle tom » 17:07 Mon 26 May 2014

When kicking off the weighing experiment, I took the opportunity at Dreweatts to invest a princely £35 in a bottle of Warre '47 that had a low shoulder level and a visibly wet capsule.

After cleaning off the muck and loose wax, and de-greasing the neck with acetone, I over-waxed the bottle without replacing the cork.

Eleven months later, I have just re-weighed the bottle, and find that it has lost just 0.1g in weight. This demonstrates that overwaxing, if done carefully, is an effective alternative to re-corking.
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill

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uncle tom
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Re: Weighing in..

Post by uncle tom » 14:40 Sun 17 May 2015

I was very kindly given a bottle of Cockburn 2011 for my birthday, which I duly tagged up - and weighed - today.

1422.3g - or around 80g heavier than the average for the past 40 years

Maybe someone in VNG spotted this article:

http://www.telegraph.co.uk/news/science ... nsive.html
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill

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uncle tom
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Re: Weighing in..

Post by uncle tom » 12:53 Sat 14 Jul 2018

I have now weighed over 3000 of my bottles, those so far unweighed being almost entirely due to being still in their owcs.

It's quite a therapeutic exercise, and not at all a chore. Whereas I would once struggle to see the level in a near opaque bottle, I am now quite content to merely weigh it, knowing that when I come to re-weigh that case, any ullaging bottles will be revealed.

Re-weighs have played second fiddle to getting first weighs completed, but those I have re-weighed have been very informative. It is clear that among bottles under 30 years old, level variations are predominantly the result of varying fills on the bottling line. It is also seems pretty safe to say that if a case of 20yr old VP is weighed and then re-weighed as little as a year later, the bottles that will subsequently ullage badly will already be showing sufficiently on the scales, if not by eye, to be spotted with reasonable certainty, and flagged for early consumption.

Another great use of the scales is when trying to establish whether a wet bottle is leaking - or has been leaked on. A very wet bottle of '84 Vargellas that I bought cheaply at Sworders last year, has revealed that it was innocent of any offence..
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill

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uncle tom
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Re: Weighing in..

Post by uncle tom » 12:56 Sat 06 Jul 2019

Now over six years since I started weighing every port bottle that passes through my hands, I am beginning to gather some useful re-weighing data.

I noticed a while back that my scales, which are marketed as 0.1g resolution, also have the ability to read in Grains, which are roughly 0.065g. I decided at a very early stage not to invest in the expense of a balance that could read to 0.01g as at that resolution, dust and crumbling labels impact the reading, and the slightest draught will send the final digit scurrying up and down. But measuring in Grains? Well, tempting..

This temptation is enhanced by the observation that the significant annual ullage rate figures, present much more neatly in Grains than Grams:

Under 1 Grain per annum weight loss ranks as Excellent
1 - 2 Grains per annum (65-130mg) ranks as Good
2 - 4 Grains per annum (130-260mg) ranks as Elevated
4 - 10 Grains per annum (260-650mg) ranks as High
10 - 20 Grains per annum (650-1300mg) ranks as Serious
20 Grains + per annum (1300mg +) ranks as Critical

Visual evidence of seepage does not kick in at a specific level. It can become apparent at as little as 5 Grains, but some bottles with ullage rates of over 10 Grains can show no visual sign (although the capsules become aromatic)

Although my data sets for young bottles are limited, initial indications suggest that freshly bottled port with driven corks loses around one Grain per annum, whereas freshly T-stoppered bottles can be as little as half that..
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill

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Re: Weighing in..

Post by Glenn E. » 18:54 Sat 06 Jul 2019

uncle tom wrote:
12:56 Sat 06 Jul 2019
Although my data sets for young bottles are limited, initial indications suggest that freshly bottled port with driven corks loses around one Grain per annum, whereas freshly T-stoppered bottles can be as little as half that..
This is very interesting. I presume it is due to the fact that a t-stopper covers the exposed end of the cork with a plastic cap?

Have you collected/separated data for different types of capsules, such as those horrible rubber things from the '60s? For example, I would expect that a full wax capsule would lose less weight over time than a simple tin capsule with no wax.
Glenn Elliott

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uncle tom
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Re: Weighing in..

Post by uncle tom » 06:29 Sun 07 Jul 2019

Have you collected/separated data for different types of capsules, such as those horrible rubber things from the '60s? For example, I would expect that a full wax capsule would lose less weight over time than a simple tin capsule with no wax.
The 1960s plastic capsules make a good seal, current ullage rates are consistently in the 1-2 Grain p.a. range. A perfectly crafted wax capsule makes an excellent seal, but the brittle wax used by the producers, often applied with indecent haste, can be worse than a foil.
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill

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uncle tom
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Re: Weighing in..

Post by uncle tom » 15:05 Mon 08 Jul 2019

those horrible rubber things
Although lacking elegance, these capsules are not so horrid when you know how to get them off.

Attacking the cold plastic with a Stanley knife is a recipe for expletives, if not a casualty. However you only have to warm them slightly and they pop off with the greatest of ease. I use the steam of an electric kettle, but for those who live in lands where this seemingly indispensable piece of kit has never caught on, wrapping the neck in a towel to avoid warming the wine and applying a hair dryer to the capsule for a few seconds should do the trick.

Once warmed, place the blunt edge of a knife under the edge and it will flip off in an instant.
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill

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