Filtering question from the Wine Talk board

Good morning,

I hope I am not intruding on the professional aspects of this board, but over on Wine Talk, there was 4 pages of acrimonious discussion about the merits and methods of filtering (bottled) wine to remove sediment before drinking.

Despite those 4 pages, it seemed to peter out before there was directly posed a question about what type of filter might be best for removing sediments without otherwise (adversely) affecting the wine, so I thought I might ask it here where there would be informed opinions.

So, in shopping around, I am being offered filters made of:

polyester
nylon
stainless steel
PTFE coated wire

available in various combinations with pore sizes of:

800 microns
600
400
300
175
150
100
75
15

Does anybody have any suggestions as to what material and size combinations might best serve for this purpose?

Thanks in advance for your kind consideration.

As far as stripping desirable components out of the wine, even the smallest of those is quite large. There aren’t any molecules important to aroma or flavor that are nearly that large. Even for mouth-feel, I suspect it would have little impact. For comparison, some wines are sterile filtered during production (0.45 microns) or given a “polish” filter (up to 5 microns).

As far as removing sediment, the stuff that is much larger than 15 microns would settle out relatively quickly. The more problematic sediment would mostly make it through the 15 micron filter. Any of the larger pore filters on your list wouldn’t do much except remove the boulders.

-Al

To clarify, the 15 micron filter would certainly help clean up the last portion of a bottle that’s been decanted. It’s essentially the same as a coffee filter without the potential issues of paper (variable pore size, absorption, potential to impart taste). But, I wouldn’t expect great results filtering a cloudy bottle of old Barolo or Burgundy that was never stood up. The 75 micron and larger filters wouldn’t do very much. For comparison, the grounds in Turkish coffee are generally 75-125 microns and those settle in minutes.

-Al

Al is correct. A 10-micron filter is commonly used in bottling - it’s typically called a “bug-catcher” filter and as the name implies, it’s there mainly to keep larger stuff out that could damage the bottling equipment. Few would even consider a wine to be “filtered” going through something that large. I haven’t looked at the other filtering discussion, but lots of sediment forms in some wines during bottle-aging that won’t be affected by pre-bottling filtration. As far as materials, with a 10-micron filter it probably doesn’t make that much difference since you’re only trying to keep out the large stuff and it should have little to no adverse impact on the character of the finished wine - go with whatever makes sense in terms of cost and logistics.

Thanks so much!

This sounds like to me…go for the finest mesh, but still don’t expect it to yield a transparent wine(?)

Yes, only the 15 micron and it won’t yield transparent wine unless it was already transparent.

-Al

Right, it won’t clean up a cloudy wine but it should help remove any large sediment pretty easily and won’t have any adverse impact on the wine. I have a plastic funnel with a fine stainless steel mesh in the spout that works well - I have no idea what the size of the mesh is but it does keep out most of any sediment / sludge.

The fine SS mesh is my preferred method, too.

Yesterday I opened a bottle of 1962 nebbiolo which I had standing upright for about 3 weeks. Properly I would give this maybe 6-8 weeks, and not surprisingly only the first 18 oz. or so decanted clearly. I poured the remainder through a 74 micron SS mesh and although loads of stuff was trapped, the wine still showed visual specks and tasted grungy. Then I used a 43 micron mesh and while the result was slightly cloudy, the wine tasted I would about 90% of the way to clear, good enough to enjoy if not applaud.

I have also 15 micron and 5 micron sheets, but since the wine barely made it through 43, I can’t figure how I might use them.