Reisling Help

WD, It depends. when you say 0.5 micron filter, that can mean two things. If you are going to sterile filter with an 0.5 micron _absolute_ filter that should be fine, but it's very difficult to sterile filter.

If you are talking about a Buon Vino plate and frame 'sterile' filter it is not an absolute filter. Yeast is pretty creative, it doesn't take much to have a fermentation restart. If your wine is good and clear chances of refermentation happening are slim, but it is possible.

I use the Buon Vino 'sterile' filter on sweet whites, but I add sorbate since I do not trust it. 2 or 3 percent RS is enough to create a hand grenade if it referments to dry. You would see a yeast layer form in the bottle if that occured. Some people can taste sorbate, most can't. If you want to use that it's often used to good effect by small scale winemakers. I filter and sorbate the end product, wait a few days at least to ensure it is still and bottle.

Another option you have is to bottle it and leave it cold. If you are not talking about a lot of wine you may want to consider just bottling and keeping it at 40F or so; anything under 50F is usually enough to keep most yeast strains from restarting. A sweet wine is usually served cold, so it may be an option to consider. No filter, no sorbate, just keep it cold.

Joe

Kiva wrote:

The filter is the fine filter for the Buon Super Jet. I know that it is not sterile. That is why I am adding sorbate. The wine is Very clear now and still. I plan to bulk age a few more months. I have sulphite levels up now. I plan to add aprox two tsp. of sobate to each 5gal carboy. The question is when. before or after I filter?

Wd

eliminating

John,

Just curious, has anyone filtered with a .5 - 1 micron filter and have re-fermentation happen after bottling with R/S? According to the size of yeast cells , anything below 5 microns should filter them out. Do we have any winemakers out there with examples of re-fermentation or is the caution just been handed down from generation to generation without actual instances of this hapenning??

Bob

J Dix> Joe's advice is good. When you add your sorbate should depend more on the

faster the

eliminating a

possible.

bottling

bentonite

Bob,

It depends on the type of filter used. A 0.45 micron (absolute) membrane filter will not pass yeast or bacteria. A 0.5 (nominal) cellulose pad filter will pass some yeast cells, and much yeast will be passed when the filter start to blind. More info here

Lum Del Mar, California, USA

Bob, I have never bottled using one of the type of filters you indicated, but I have heard stories of those who have which included fizzy and exploding bottles, corks ejected etc. The "riskiest" method I use is to take a .45 micron nominal cartridge filter and use it in line with my bottle filler as my only filtration. (using NO Sorbate). I have found in my situation that this has been a reasonable method so long as you ensure the filter is not becoming "blinded" or plugged up as Lum stated. It certainly is safer to use an Absolute filter of .45 or less, but the cost is about tripled for the filters so I have been using the Nominals with good luck. The other point I was trying to make is that Yeast is floating around in the air all the time, and if you filter your wine and then let it bulk age without Sorbate you may get a refermentation. Never tried it, but I dont think it's a good idea in my opinion to filter without Sorbate and let the wine bulk age. HTH John Dixon

John,

I guess what I really wanted to say was that in all my research, I haven't found any documentation that says yeast cells can be smaller than 4 microns. Actually, only one paper mentioned the 4 microns and all others had 5 as the lower limit for WINE yeast cell size. I know .45 absolute is needed for MLB BUT if the filter doesn't bind , I don't see why a 3 micron or 1 micron filter wouldn't be enough to filter out yeast cells. Now with that said, I use 1 micron in series with .35 micron for my filtering because I've been scared half to death by the posters here ;),BUT I'm just curious if anyone has had any luck filtering out yeast with bigger micron sizes besides what is generally recommended here. Thanks for all the responses.

Bob

J Dix> Bob,

indicated,

filtration.

filtering

_absolute_

usually

sorbate,

fermentation

Hi Bob,

It is my understanding that you are absolutely correct on the size of the yeast cells themselves. The problem as I understand it is that when the yeast multiply by budding, the buds are much smaller than the yeast and rogue buds in your wine can grow into viable yeast and restart fermentation, hence the need to absolute filter to a level that will exclude buds as well as mature yeast cells.

CHEERS!!

Aaron

Hi Bob, Why do you even bother to filter? People have been making wine for thousands of years without filtration; myself, for instance! :-) Seriously, what are you gaining? Pardon my ignornace, but I just don't get it..... Bob<

Please excuse the double post. Lum

Ah, so you are doing it to win prizes. That explains a lot.

But my wines do appear perfect. And the taste ain't half bad either! :-) Blobert!

The only downside I've tasted (one-dog-show, side-by-side, filterend and non-filtered pair of wines from same batch, both settled after bottling) is a little less complexity after filtering - but upside was slight chalky feel was gone.

There's a price for everything; not often get all positives from any action.

Gene

Lum wrote: