Filtration

Anything to do with Port.
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JacobH
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Filtration

Post by JacobH »

I have long been dis-satisfied with my decanting and, in particular, the problems of filtering the Port to get a clear liquid in a reasonable amount of time.

Over the years, I have used everything from coffee filters, muslin, traditional decanting funnels (which have a metal plate with some holes punched in) and modern decanting funnels (which have a gauze).

I used to find the best filtration was achieved by coffee filters but I frequently had terrible clogging problems which meant it would take hours to decant a bottle.

These days, I tend to use a decanting funnel that came with a case of Port from Chuchill’s which has a moderately fine mesh. It is an ok compromise but I still get bits of sediment in the Port and sometimes it still clogs if I am not steady enough with my hand.

I appreciate that there has been much previous experimentation but that has tended to concentrate on taste and smell rather than the visual qualities of the Port and ease of use.

My current thought, therefore, is to use a succession of meshes in increasingly small diameters to allow filtration of all visible particles without clogging.

The question is what sizes of meshes? Looking online suggests that water filters use 75 to 100μm to remove sediment; 50μm to remove visible particulate; 10μm to remove most chemicals and 1μm to remove bacteria and viruses (!). One manufacturer of meshes suggests using 30 mesh (600μm) for a tea-strainer; 200 mesh (75μm) to remove spice powders from mulled wine; and 400 mesh (37μm) to “greater clarity, but slow speed under gravity filtration”.

This feels to me as if a selection of different grades from about 500μm to 50μm might be the way forward, to remove the sediment without clogging.

The next question is how to do this. You can buy sheets of mesh quite cheaply but that might be a bit awkward to use. People who keep fish sometimes use filtration “socks” which might have the advantage of ease since you could pour a whole bottle through them quite quickly. Some sizes are available for brewing, too, in either sieve of bag form.

There is also one company on ebay that sells a stacking selection: this seems quite attractive, or you can also buy 5cm diameter “test sieves” that I think are used in labs for testing how much sediment of different sizes are in a solution. These have the advantage of being stack-able disks but may be a bit too big for use with a decanter.

Before ordering some stuff and having a play, I was wondering if anyone else has messed around with this sort of stuff before and can give me some thoughts?
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MigSU
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Re: Filtration

Post by MigSU »

You could try a Büchner setup :D
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JacobH
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Re: Filtration

Post by JacobH »

Don’t laugh but I have considered that! But I thought that gravity filtration is less likely to strip something from the Port that should stay in there...
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jdaw1
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Re: Filtration

Post by jdaw1 »

JacobH wrote: 13:57 Sun 24 Jul 2022There is also one company on ebay that sells a stacking selection: this seems quite attractive, or you can also buy 5cm diameter “test sieves” that I think are used in labs for testing how much sediment of different sizes are in a solution. These have the advantage of being stack-able disks but may be a bit too big for use with a decanter.
Only £4.49 each: buy a selection; be the guinea pig.
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JacobH
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Re: Filtration

Post by JacobH »

More than happy to be the first guinea pig; was posting to avoid being the second!
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jdaw1
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Re: Filtration

Post by jdaw1 »

We did a decanting experiment with a magnum of N63, and concluded that Port is robust. Anything sensible would be, err, sensible.
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DRT
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Re: Filtration

Post by DRT »

I have been using one of these for about three years. It is excellent.
"The first duty of Port is to be red"
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JacobH
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Re: Filtration

Post by JacobH »

DRT wrote: 00:04 Mon 25 Jul 2022 I have been using one of these for about three years. It is excellent.
I have a Bodum filter coffee maker which has one of those in a matching jug which is excellent for this sort of thing, because of the very large capacity in the filter. If I didn’t like my proper Port decanters as much, I’d probably use it all the time for wine.

I appreciate that most of these methods are good enough. And actually just decanting without filtration is generally good enough, too. It’s just that I would like to see if I can move from good enough to perfection.
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mosesbotbol
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Re: Filtration

Post by mosesbotbol »

I buy cheese cloth, several yards at a time. Do use the same piece over and over though. Only one layer, I want it filtered, but not filtered too much. Just enough to catch stuff, but not wait 5 minutes for it to pass through.
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Glenn E.
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Re: Filtration

Post by Glenn E. »

I purchased one of these sets from Wine Enthusiast many years ago and have been using it ever since. The mesh isn't super fine, but with a steady hand and careful observation it is usually pretty easy to keep almost all of the sediment out of the decanter. I do stop pouring as soon as sediment starts to flow, though, so I'm probably not actually making much use of the strainer for anything but cork bits anyway. If every drop into the decanter is necessary, a couple of layers of cheesecloth in this setup generally make it possible to pour everything out of the bottle with only superfine sediment getting into the decanter.

I hand pour bottles of Porto Souza which are somewhat infamous for their sludgey sediment and normally don't have any problem.

I think the key is to properly stand up your bottle a few days before decanting, and then decant carefully, and be willing to stop decanting once the sediment starts to trickle into the decanter. That last bit can then be poured separately, left to stand for 30 min, and serve as the quality control sample.
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JacobH
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Re: Filtration

Post by JacobH »

The “Aerating Funnel” from that set is the one Churchill sent to me and I really like it, although it is a bit too wide to sit in the necks of many of my smaller decanters. I wish it was just 10% narrower!

I admire your ability to stand a bottle up for a few days before opening. I tend to think: “what would I like to drink tonight?” and then go to raid the wine fridge...

I’m going to buy a set of those stackable filters and see how well they work.
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PhilW
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Re: Filtration

Post by PhilW »

jdaw1 wrote: 19:45 Sun 24 Jul 2022 We did a decanting experiment with a magnum of N63, and concluded that Port is robust. Anything sensible would be, err, sensible.
While port is generally robust, and any sensible decanting method used with a robust port is likely to cause minimal noticeable effect on the decanted wine, the effects of some methods can become more noticeable on more delicate port.

This thread has motivated me to add a postscript to my original decanting experiment thread which you referenced, something I had intended to do for some time, to update and address this.
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JacobH
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Re: Filtration

Post by JacobH »

I have been wondering if there is an advantage of using something that is non-absorbent for filtering. My assumption is that if a liquid is absorbed and then de-absorbed there is much more likely to be an impact on flavour than if the filter fabric is completely inert. This could be from a flavour of the material but also because an absorbent fabric is likely to be less precise in its filtration (e.g. it might strip too much). That was why I was looking at materials which are made specifically for filtration: I presume they will precisely remove particals above a certain size but not below. Of course this may only really impact very old wines which are very fragile.
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uncle tom
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Re: Filtration

Post by uncle tom »

My method, which works very well and very quickly is to use a funnel - and whilst I use an antique one at home, cheap 3" diameter plastic ones will also work just fine, and these:

https://www.ebay.co.uk/itm/154692044778 ... SwtYdhilkH

8 ply BP type 13 gauze swabs (non-medicated) 7.5cm x 7.5cm

I put two into the funnel at 45 degrees to each other. The port drains through in seconds, yet it catches pretty much every last bit of solid matter.

Edit: Checking back I last bought these from Medisave - https://www.medisave.co.uk/gauze-swabs- ... f-100.html

It pays to buy plenty as they are very cheap in bulk
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DRT
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Re: Filtration

Post by DRT »

JacobH wrote: 11:06 Mon 25 Jul 2022
DRT wrote: 00:04 Mon 25 Jul 2022 I have been using one of these for about three years. It is excellent.
I have a Bodum filter coffee maker which has one of those in a matching jug which is excellent for this sort of thing, because of the very large capacity in the filter. If I didn’t like my proper Port decanters as much, I’d probably use it all the time for wine.

I appreciate that most of these methods are good enough. And actually just decanting without filtration is generally good enough, too. It’s just that I would like to see if I can move from good enough to perfection.
I place my metal coffee filter in a suitably large funnel and decant directly into a decanter.
"The first duty of Port is to be red"
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JacobH
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Re: Filtration

Post by JacobH »

I have been experimenting.

I took a bottle of Quinta de la Rosa 1999 LBV and decanted it into a jug through the funnel which Glenn linked to above. This has a reasonably-fine mesh and is what I use for most of my decanting. Unsurprisingly, it caught a decent amount of sediment but also decanted the wine without clogging.

I think poured the Port from a jug into a decanter through the stack of three filteres I bought from ebay: 250μm, 125μm and 50μm.

The Port passed directly through the 250μm and the 125μm filteres without any clogging. They both removed a decent amount of fine particulate. I’m not sure if this two-stage process is necessary: I think it may not be. The 50μm filter, however, clogged badly. It was necessary to clean it three times to decant the Port. Each time a fine sludge was left on the filter.

A glass of the Port filtered down to 125μm had some small visible particulate at the bottle. The 50μm filtered one was much clearer. I didn’t notice any change in aroma or flavour as a result of this filtration.

I feel for drinking completely clear Port, 50μm should be the goal. However, I am not sure how practical it is. My instinct is to buy some more filters which are between 125μm and 50μm and see if a more gradual filtration avoids clogging to the extent that one can free-pour the Port through the filters.
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JacobH
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Re: Filtration

Post by JacobH »

DRT wrote: 17:32 Fri 29 Jul 2022 I place my metal coffee filter in a suitably large funnel and decant directly into a decanter.
Yes: I was more thinking about using the glass carafe as a decanter since it has a nice shape and a low centre of gravity, even with the filter inserted. Having had a few near misses with towers of funnels over the years I always try to avoid that!
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Re: Filtration

Post by SCP »

Having tried lab-grade filter paper for a while and been frustrated by how slow / clogging it is (and the amount of liquid absorption).

I have actually been using a clean, heavily washed, 100% cotton white handkerchief in a funnel for the past couple of years - less of a problem with liquid absorption, not really noticed a concern in terms of any taste difference. Not sure if this would be better or worse than using a muslin.

Nevertheless, it does sound like a stainless steel gauze would be an upgrade...
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JacobH
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Re: Filtration

Post by JacobH »

Following my previous post in August, I bought some more filters which I have been playing with. I now have a set of 250μm, 125μm, 90μm, 75μm and 50μm.

My conclusion is the best grade for filtering Port 75μm. This filters out any particulate which can be tasted whilst remaining reasonably free pouring. With older VPs where the liquid is quite translucent and so there is a strong contrast between the sediment and the Port, it leaves some visible traces in the bottom of the glass. To remove these, you need a 50μm one. However, I find the 50μm is far too prone to clogging to be used on its own for any large quantity of Port. Quite good for getting the tartrate crystals out of white wine though. Whether you can go straight to the 75μm filter depends on how much wine you are decanting; how much sediment there is; and whether you have stood the bottle up for long enough. If you are grabbing-and-pouring a sediment-heavy bottle, it may be helpful to run it through one of the courser grades first (it doesn’t particularly matter which one) to get the worse of it out before running through the finer filter.
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Re: Filtration

Post by Lucas S »

That's amazing research. Are these stainless steel 75μm filters or nylon or what?

If you have a specific stainless one to recommend, please do so.
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JacobH
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Re: Filtration

Post by JacobH »

Lucas S wrote: 07:38 Fri 28 Oct 2022 That's amazing research. Are these stainless steel 75μm filters or nylon or what?

If you have a specific stainless one to recommend, please do so.
These were nylon from the ebay link up-thread. I think they are designed for aquarium use since the nylon has been stretched over a piece of PVC pipe which has then been glued inside a slightly larger PVC pipe. It’s actually quite a convenient design!

My next step is going to be to buy some sheets of fabric and steel filter in 75μm and 50μm and try to work out a good way of working them into a larger funnel. I’m wondering if small embroidery hoops might be useful, although there is probably a lab-based system which I haven’t yet identified!
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Re: Filtration

Post by jdaw1 »

JacobH wrote: 14:50 Wed 02 Nov 202275μm
xkcd.com/129:
A black hole the mass of the Moon would have an event horizon about the size of a sand grain. … a black hole moon would be a grain of fine to medium-fine sand, and could pass through a sieve of size ASTM No. 70 or larger.
Which might not be very relevant.
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uncle tom
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Re: Filtration

Post by uncle tom »

In normal mechanical filtration, ever smaller gaps leave ever smaller particles free to pass through. However, the particles that form fine hazes are too small to be mechanically screened, so in wine making, fining agents, that serve to agglomerate fine particles are used.

However, there is a third way. The surgical gauzes I use for filtering attract tiny particles that should, in theory, be able to pass through. I don't fully understand the physics of this, but there is no doubt that fabric screens are vastly more effective than metal ones, where haze forming particles are concerned.
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JacobH
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Re: Filtration

Post by JacobH »

I’ve been reading about filtration in the context of making filter / “pour over” coffee which has been interesting.

The consensus seems to be that paper filters strip the most from the coffee in that they remove not only the grounds but also the dust that arises from the grinding process and also many of the oils present within the coffee. They are also designed to allow the water to pool in the bottom before draining which, of course, is helpful if you are trying to brew something but is less desirable for filtering wine.

Metal filters, on the other, are poor at striping out the micro particles but do leave many of the oils in. They also tend to allow water through them more quickly, including through their sides (which is a bad thing for coffee but a good thing for wine).

Cloth filters are thought of as middle ground: removing much of the fine particulate but not so many of the oils. The main reason they are not so popular in Europe / North America is that they are rather fiddly to clean compared to paper or metal.

You can also buy solid filters made out of a curious porous ceramic, but these seem to be quite rare and expensive.

I presume wine does not have much in the way of oil in it compared to coffee, which is why paper has little notable impact on flavour. I presume also the popularity of cloth filters supports what Tom has been seeing with surgical gauze.
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Andy Velebil
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Re: Filtration

Post by Andy Velebil »

Paper filters for wine/port are horrible. They strip way too much out and leave wine tasting what is best described as metallic to me.
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