Making aromatic whites - poll

I use 2g/gallon KWK bentonite.

At this point I fine with Isinglass. In my hands Riesling needs a second fining step for real clarity. .....

I don't care for sorbate but I do use a MiniJet with the #2 pads. This has worked well for me but I would NOT recommend the #3 pads. They clog no matter how clear my wine is - it. just spews everywhere.

.... I am still not sure

I actually think the filtering step helps the degassing process. I've separated portions which don't get filtered and can't say that I find much diference in either aroma or taste. In fact last year I also separated out some of the wine prior to the 2nd Isinglass fining step. Here I did find a difference but prefered the wine that had been put through the Isinglass fining step.

I have never had a problem with refermentation using the proceedure above and I usually have 0.5 - 1.5% RS depending the other aspects of the fruit.

RD

Thanks, RD. I also tend to use lysozyme, just forgot to mention that. Just to clarify one thing - you do one step filtering with #2 pads and then bottle after (some time) without any sorbate? I always thought the pass through #3 was necessary to get a decent chance of avoiding refermentation without sorbate.

I don't have a clogging issue with the #3 pads if they are used after a #2 pad so maybe that's the difference?

I agree filtering definitely helps with degasssing but am concerned about the seeming "violence" of the process, i.e., that the amount of CO2 that's generated and the speed at which it bubbles through the wine is negatively affecting the quality. But I don't have comparison data for this, it's just an impression.

Pp

with Isinglass. In my hands Riesling needs a

the #2 pads. This

step helps the degassing process. I've

Yes, I do but I should mention a few other things: i) I usually use Cote de Blanc which has a tendency to poop out. ii.) Once fermentation is complete and settled for several weeks, I rack off the settled lees before beginning the fining process. iii.) I cold-stabilize for 3-4 weeks in an old frig set as cold as I can get it. iv.) I keep my bottled wines and my wines in progress in a consistently cool environment.

I'm not sure if the # 3 MiniJet filter pads are rated for 'sterile' filtration (i.e., 45 micron) so I couldn't comment on whether this removes yeast well. It does occur to me that a second filtration step (and the concomitant handling, aeration, and 'violence', as you put it) might result in additional losses but I have no data on this. I try for minimal racking and aeration - I rack after alcoholic fermentation, then again after bentonite/isinglass/cold stabilization, then filter.

It sounds like you're talking about CO2 entrainment of aroma compounds. I would think cool fermentation and storage temperatures help here.

RD

Carbon dioxide sparging strips aroma When I was the chemist for a large commercial cider maker we occasionally used CO2 sparging to strip aroma when making other products.

Bob M

Evenin PP-

I was recently over in Germany for a business trip and hit their wine region. They were having their wine festival at the time- and let me tell you it doesn't take very many samples at 0.4L per sample to mess you up...

But back to your question: I believe it to be the grapes.

I have tasted the juice I can get here in NY for a couple of years and it's always so-so. There I was able to taste the grapes and the juice that was going to be made into the wine and I'd have to say there was a factor of 4 or 5 difference in terms of how the flavours exploded off of my tongue. Litterally placing a grape in your mouth was equal to sucking on an orange or apple or grapefruit ...

When I got back to the states, I purchased some riesling to work with. It was very ho-hum mediocre stuff.

So... you may be doing everything right, but you may not be getting the best juice or grapes. That's going to be next years experiment- I'm going to goto the local wineries and ask to buy 3 lugs from each that I know produce EXCELLENT red wines... in hopes that I will be able to determine whether I'm the one not cutting it or my supplier is.

Jas> I make aromatic whites (Riesling, Gewurz, occasionally Viognier) every

That was my concern, exactly. I think I'll degass manually before filtering this year, not ideal but should be gentler.

Pp

Thx, Jason - yes, that is definitely one possibility. The main reasons I suspect the process:

- there is good aroma during and at the end of the fermentation but not in the finished wine, so that indicates aroma loss during fining, aging, or filtering;

- I've made a couple of wine with the same grapes that a local commercial winery is using for their wine, so I can compare the results against a benchmark. Of course, in this case there could be a difference in the grape processing as well.

I'm thinking I'll run a test next year too - start from the same source and do several gallon batches in parallel with a different treatment to see if I can pinpoint the problem... if I can find time for this.

Thx,

Pp

PP, I did many of these kinds of experiments years ago and often had mixed results. I became frustrated in not being able to explain many the unexpected results. I discussed the issue with my daughter who is a microbiologist. She encouraged me to "do the other half" of the experiment. In this case, do several gallon batches in parallel using the SAME treatment. I thought I had wasted the money for my daughters education until............ I did the experiment. Then it became apparent that I got my moneys worth. Good luck, Lum