Lees 101 questions

Hi Michael,

I think you've got it backwards. People stir Chardonnay aged sur lie because (for one reasons of many) the lees absorb oxygen, even more effectively than SO2 does. And since in France, where the practice is common, SO2 is often not added until after ML finishes naturally in the spring, this batonnage is really important in helping prevent oxidation.

I've never heard anyone practice3 batonage to introduce oxygen, though I suppose stirring always does introduce some oxygen from the surface above the wine.

Dave

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Yeah lees stirring takes up O2, it also brings some over desirable flavours out of the yeast as it breaks down.

Gross lees are any lees that c> >#1

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Yes there is, and I think it's an important one to make. Gross/heavy lees should include any lees which contains vegetal particulates (with juice clarification at > 200 NTU in must), tartaric crystals/yeast/precipitated colloidal matter conglomerates, fining particulates. Or more generally, particles deposited within 24 hours and > 100 microns. This lees is not desirable and wines containing it should be racked off it. Keep in mind that some winemakers clarify their juice prior to fermentation enough to avoid any of this kind of lees in their wine.

Light/fine lees is defined as yeast from the end of alcoholic fermentation and afterwards, and lactic bacteria deposited towards the end of MLF. Or more generally, particles remaining suspended 24 hours after the wine has been moved and 1-10's of microns. This is the lees that we want to stir with.

Obviously I can't see *your* wines but it *sounds like* you have some gross lees in both the red and the white. I would rack them both. You could deliberately pick up some of the lighter lees in the white when you do this if you are sure it would be defined as light/fine lees and you can control your racking procedure adaquately. For the red, I'd rack it off any lees whatsoever at this stage.

HTH, Ben

I wonder if you are mixing up your processes or we are not understanding your question.

You stir the "must" when you first start fermentation. This introduces oxygen so the yeast will reproduce and it keeps mold and other nasties from growing on the cap, the crushed fruit that rises to the top, and it keeps the cap from drying out and improves extraction.

But if you are talking about after fermentation is over, then you are really talking about Sur Lie as described above and you certainly are not trying to introduce O2.

It can be confusing.

Ray

On what's been said about the role of oxygen in lees stirring (and of course I'm talking post fermentation):

I wouldn't say lees stirring is done to oxygenate wine, but I wouldn't say it's really done for the purposes of absorbing oxygen either - that's just a useful extra.

Stirring inadvertently adds oxygen to a wine when the barrel/vessel is opened and the turbulence associated with lees stirring occurs. Whilst the aim isn't to add oxygen to the wine at stirring, I would say it is necessary this takes place in the reductive environment created by the stirring itself.

Ben

Let me try this again. I see at least three reasons to stir lees:

(1) absorb oxygen (i.e., oxygenate) to avoid reductive problems in the lees such as H2S (2) get greater exposure of the leesy goodness to the wine (3) remove oxygen from the wine

I guess the question is really about how much oxygen is in the wine? I was under the impression that there was very little oxygen in the wine and therefore stirring up lees in a bunch of oxygen-free wine wouldn't do much to oxygenate the lees. But it sounds like this may be wrong... that indeed the wine does contain a meaningful amount of oxygen that can be absorbed by the lees. Correct?

...Michael

Thanks. Good, I've been wanting to have this conversation. I have been to many winery websites and have talked to a few winemakers about racking. Now mind you that most of these conversations have been about pinot (which is mostly what I've made), but the process I've heard basically looks like this:

Ferment Rack directly to barrel Let it sit for a long time without stirring or racking Gently (e.g., bulldog pup) rack into nitrogen sparged tank to settle Bottle

What gives?

Dunno. I haven't seen your wines. I think the idea is to remove any oxygen that might be there, since the wine has no SO2 and is therefore utterly unprotected against oxygen. The strring is done to expose the wine to the lees, and as an extra added bonus, the stirring is an antioxidant.

Dave

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How much oxygen the w> oxidation. I currently have a 6 gallon batch of Viognier aging sur lie but

I have done in-vessel stirring (i.e. without any opening of the vessel) and have found that if you keep it up for long enough the wine will become reductive. If I were you, I'd keep close tabs on the wine (taste it relatively regularly) to check where it's at.

Ben

If you have been successful with this approach, you've been lucky. FWIW, I'd recommend that you make a few changes:

Obviously, you meant to include pressing. I'd **highly** recommend that you press to a tank or some other large container and let the heavy stuff settle out before racking to barrel. That only takes an hour or two, and you'll leave a lot of potential big problems behind in those gross lees.

That may be OK, but you certainly want to maintain the free SO2 and zero headspace in the barrel. BTW, tasting while you're topping is _mandatory_ during barrel aging. I'm sure you can live with that. :^)

You forgot to mention fining prior to settling. Pinot Noir may not require fining for excessive tannin, but I highly recommend a light bentonite fining at least. There are two reasons for this: (1) Protein stability - especially in the case of Pinot Noir. This wine tends to throw a protein haze in the bottle, very much like white wines that haven't been bentonited. Just 1 pound/1000 gal. of bentonite is sufficient to prevent that in most Pinots. (2) Improved clarity is a nice side benefit from bentoniting. Also, I've noticed that bentoniting tends to bring the fruit more to the fore in Pinot Noir - most noticeably in the nose. Don't ask me why. I can't rationalize that observation. It's just something I noticed.

Be sure to check and adjust (if necessary) the free SO2 just before bottling.

Tom S

One thing nobody's mentioned is that stirring exposes the wine to the relatively un-extracted oak at the bottom of the barrel.

Tom S

Yes, sort of. Actually a lot of the wine went directly from the fermentor to barrel without a stopover in the press. This was done to minimize oxygen contact and was accomplished by pushing a pasta strainer down into the must and then taking the wine out of the pasta strainer! So while there were no seeds or skins, I'm sure there's quite a bit of other particulate matter in there... but probably no more than if I pressed and then went straight into barrel. I hear you on the settling out the gross lees. I'll definitely do some more research on this before next year.

Yick. Never touch the stuff. Currently, none of the wines have SO2 additions. I innoculuated a few barrels for MLF and I'll run another chromotography test next week to see if they're done. My guess is MLF will be complete and I'll sulfur. For other barrels, I'm letting MLF take its time and they probably won't complete until Spring. Obviously these won't have SO2 protection for several more months. Let's see how it goes this year, but I now know why people innoculate for MLF - it's a bit nerve wracking.

Haven't really thought about fining. Again, I've just been reading what pinot pros do and it seems like the higher end produces don't fine or filter. BTW, why bentonite and not egg whites or some other fining material?

...Michael

I do periodic stirring (usually once every 2-3 days) using a food turntable (see

for a pic). Stirring has given the wines more body and complexity and I'm quite happy with the results (though it is a stylistic choice). I have had some problems with wines going reductive, but if you monitor and correct when the problem arises there's no problem.

Ben

That's true, but many of those wines throw a protein haze in the bottle. I _really_ hate that!

BTW, why bentonite and not egg whites or some other

Bentonite is very specific to proteins that cause cloudiness due to heat instability. The other fining materials (egg whites, gelatin, isinglass) are mostly to reduce tannins. All of them tend to promote clarity.

Tom S

Maybe I'm not following your procedure properly, but wouldn't this method (with the strainer) introduce *more* oxygen than simply racking directly? Why not just wait till the cap rises fully, rack (and press) to another vessel, wait for particulate settling, then rack to barrel?

I would say a lot of those pros d> > Also, I've noticed that bentoniting tends to bring the fruit more to the

Interesting observation Tom. I don't doubt it really. Isinglass is widely reputed to give brighter fruit, and I'd incline to agree with that from experience too.

Ben

The goal was to minimize oxygen contact. So I took the strainer (it's about a foot deep) and pushed it down into/through the cap and then put a hose into the strainer to rack out. The only oxygen contact was the very top of the strainer. The strainer kept things like seeds and skins out. I think this was way less oxygen then putting it through a press. I also racked most of it into barrel a bit sweet (about 2-3 brix) for extra protection.

So, despite being a winemaking neophyte, I actually was able to track down shockingly good fruit. But it sounds like I should definitely do some trials with bentonite to see how it impacts clarity and taste.

...Michael