What Does Filtering Do???

You would need to filter with a very small (3 microns you mentioned is right) pore size to remove the yeast. The equipment to get sterile filtration would be impractical and too expensive for a home winemaker. Many home winemakers use filters mainly to remove particulates and make a clearer wine. They do not filter out all the yeast.

Now, as to your mead . . I too have had meads ferment for a very long time. A couple were going on two years and still bubbling ever so slowly. This is a problem with mead that I believe has to do with acid levels. Unfortunately I never tested the acid on my slow batches.

If your alcohol level is high enough and you are happy with the sweetness level, you can chill your wine in a fridge to stop the fermentation, then carefully rack it cold and add potassium sorbate and potassium metabisulfite to stabilize it and prevent renewed fermentation. This can be a bit tricky to do. For my batches, my alcohol levels were too low, so I added some everclear to bring the alcohol up and then stabilized it. That seems to have worked well for me.

I'm quite new to this but I don't think filtering is a recommended way of stopping a ferment. Filtering is I believe carried out once fermentation has already stopped either naturally or by the addition of potassium sorbate and sodium metabisulphite. Filtering then removes hazes and dead yeast cells, leaving the wine brilliantly clear. I'm guessing if it can remove dead yeast cells it can also remove live ones but I wouldn't depend on it removing every last one. I'd stop the fermentation first as described above, then filter.

Btw, I'm talking about filtering using something like the Vinbrite Mk3.

Greg, I think you made a mistake on the filter size for the removal of yeast. You want to go below .5 microns (1/2 0f 1 micron) to remove yeast. Typically you could use a .45 micron absolute filter to get this done, but may will use the .2 micron absolute in the line right before the wine goes in the bottle. I will tell you that as a home winemaker I have used a standard .45 micron cartridge filter in line with my bottle filler to remove the yeast and not have to use sulphites.(about $35. each) I certainly wouldn't recommend this for commercial practice, but I have only had a couple bottles of "sparklers" and haven't ever had one blow up on me. Not truly sterile, but has been good enough for me for several hundred gallons of off dry wines. HTH John Dixon

Unfortunately

metabisulfite

stilettorain wrote "I recall from a brewery tour, that some beer brewers

Nate - You need a finer filter than 3 microns to remove yeast and it's buds. I would use a 0.45 micron absolute membrane filter or one with even smaller pore size. To stop fermentation in a wine with residule sugar first chill it to freezing temperatures, then rack off the settled material. It's important to use a yeast that is easily stopped by cold temperatures such as Epernay 2. If the wine is very clear once it warms back up you can add K sorbate to block further fermentation. If the wine still has some haze following warm up you may need to repeat the chilling/racking step to remove more yeast before stabilizing. If you have suitable equipment [several hundred $] you can sterile filter the sweet wine, after chilling/racking, instead of adding K. sorbate. But you need very good technique to avoid contamination of the filtered wine with yeast cells floating around your basement winery.

Bill Frazier Olathe, Kansas USA

I don't think acid is the problem. In fact it is not really recommended that you try to adjust acidity before mead is finished because of the natural buffers in honey. This is different from other wines.

From my readings, it is my understanding that slow fermentation in meads is generally caused by lack of nutrients. Many (but not all) honey's are very deficient in nitrogen. It is generally thought that slow fermentation is not a particularly good thing for honey and it would be better to speed it up. It is really helpful to know the type of honey being used to know how much nutrient to add.

Ray

Wow, Thanks everybody. Some really good suggestions here. I'm thinking, the cold stabilization idea may be the best for me. I may also bottle in 22 oz. beer bottles so if I do have some blow outs, it's just a cap, not a glass bottle that explodes. Thanks again. Nate

Yes, John. Thanks. I meant to say that, but somehow repeated the "3 microns" from the original poster's message.

For whatever it's worth, I had several carboys of what appeared to be perfectly clear white wine. Because I wanted to try out a new filter with 0.2 micron cartridge, I put several of the carboys through it and the difference was amazing. What initially appeared clear now absolutely sparkles.

Lee

Who cares, so long as it still works on the old grey matter! LOL!!!!! Bob

Mite there be a loss in flavour when the wine is forced through cardboard?

Honestly, not that I've noticed. It's obviously all subjective, as are all senses. But when I say that the filtered wine sparkles, I'm not exaggerating, and I think my visual sense is sharper than my olfactory sense, so for me, it's a winner.

Lee