Friday, March 28, 2008

Roberts Road Pinot Analysis

Results of the analysis of the post-pressing Pinot sample:

Alcohol15.13% (v/v)
Titratable Acidity5.88g/L
Malic Acid1.33g/L
Volatile Acidity0.43g/L

This confirms that I did not add enough water before the start of fermentation. The alcohol is too high – some people may like wines over 15% but I find them unbalanced and fatiguing to drink – but more alarming is that the wine is not bone-dry.

My operational threshold for "dry" is 1.00 g/L (0.1% w/v, or as Vinquiry reports, 100 mg/100 mL). Some experts are OK with twice that value. But from the standpoint of assuring the most stable, most spoilage-resistant wine the only acceptable value is really "none detected". In practice, I am happy and relaxed if the residual glucose + fructose is less than 0.20 mg/L (20 mg/100 mL).

Clearly this wine is not there yet. Some guys would pitch for malolactic anyway. Not me. I want to wait for the wine to get below that 1.00 g/L threshold to make sure the bacteria produce a minimal amount of volatile acidity.

Thursday, March 27, 2008

2007 Roberts Road Pinot Pressed

Yesterday I pressed off the Roberts Road Pinot. The Pod readings were -3° Brix and 65° F. The cap was still up and I did not mix it before starting, other than putting a hole through it with my hand to pull out the Brix sensor before installing the press ram.

The pressing went routinely. As before, I set the unit to heavy press and then switched to manual mode on completion of the auto program. In maunual pressing mode I took the ram to maximum pressure 1) every 30 seconds for 16 cycles, then 2) every 60 seconds for 9 cycles, then 3) every 5 minutes for 7 cycles.

The last two 5-minute cycles the motor tripped out immediatley, indicating I had pushed the ram down as far as it was going to go without really long waiting between cycles. This is improved performance compared to my prior pressing of the Napa River Ranch Cabernet. I attribute the difference to using enzyme on the Pinot.

Yield was about 10.8 gallons. This time I don't know exactly what the final volume was because I did not rack the wine back into the Pod after pressing, where it is easier to measure. I filled a 3-gallon carboy, filled a 30 L (7.9 gal) Vernou M+ toast barrel to within 3/4" of the bunghole, and collected about 2/3-gal of heavy lees for settling.

In my commercial production I usually press Pinot Noir to tank and then move immediately to barrels before extensive settling. I believe that the presence of the extra lees in the barrel result in increased aromatic complexity and improved mouthfeel.

Today I will take a sample to the lab for analysis. Once I confirm that the alcoholic fermentation is complete I will inoculate for malolactic in the barrel and carboy.

Sunday, March 23, 2008

Inflection Point

Friday morning I worried over whether or not the fermentation would stick. I got my answer Friday afternoon, where the must readings were 0° Brix at 79° F before punchdown #11. The graph above shows a clear inflection point from the morning reading to the afternoon.

This sort of curve inflection indicates a second yeast population picking up as the first population slows – I have observed this inflection before when re-inoculating a sticky ferm. It appears to me that the RC212 inoculum – added at 9.5 days – took a while to pick up, but did. I also noticed that the hints of sulfide aroma I had observed in the morning were completely gone, so I did not add any DAP after all.

Friday afternoon I lowered the setpoints again, to 74° and 77° F. I made only one punch (#12) on Saturday, where the readings were -2° Brix and 73° F. Once again I dropped the setpoints, to 68° and 71° F. I also put the lid on the Pod, since the fermentation is effectively complete.

At punch #13 today, the must read -3° Brix and 68° F. I made the final adjustment to the temperature setpoints, to 66° and 69° F, where they will stay through pressing.

I am still on track to press on Wednesday the 26th as I originally planned, after 14 punchdowns and 16 days of cuvaison. Yesterday I started prepping the barrel with the first fill, and today I gave it the second filling with hot water.

Friday, March 21, 2008

Past The Peak

Wednesday night when I checked the Pinot ferment there was no evidence of Kloeckera activity (no aroma of ethyl acetate) so I went forward with my plan to inoculate the must. I rehydrated 11 grams of RC212 yeast (25 g/hL) in a mix of 200 mL distilled water plus 13 grams of GoFerm nutrient (30 g/hL) at 104° F for 20 minutes.

I added a pinch of table sugar to proof the yeast prep. To my mild dismay the inoculum foamed only very slightly. I pitched it into the must anyway with punchdown number 7, though I would have been more sanguine if the inoculum had foamed extensively. After the punch the must was down to 23° Brix at 82° F; I moved the setpoints to 88° and 91° F.

When I checked the Pod early yesterday morning the must had overflowed slightly – perhaps a fistfull of pommace and 250 mL of liquid had gone over the side. It never ceases to amaze how much of a cleanup mess is created by such a small loss.

The Pod was reading 12° Brix at 91° F. For the first time in my WinePod experience, the cooling came on during punchdown #8. I moved the setpoints to 91° and 95° F. At the afternoon punchdown (#9) the must was reading 7° Brix at 92° F and the cooling did not come on until I dropped the setpoints to 83° and 86° F.

This morning at punch #10 the Pod was registering 4° Brix at 83° F, so according to plan I further lowered the setpoints to 78° and 81° F.

So I am past the most stressful (for me) part of the ferment. The yeast may be stressed a little – there has been a whiff of sulfide at the last couple of punchdowns. If it seems that the sulfide is still present at this afternoon's punch I will probably make a very small DAP add – maybe 0.1 g/L – even though I normally prefer not to add DAP so late in the ferment.

The only worry I have left is whether the ferment is going to stick or not. The slope of the sugar curve looks fine this morning – at this time the slope suggests that it is not going to stick – but the next data point is critical. I will be reassured if the reading this afternoon is between 3° and 2° Brix. If I see a reading of 1° Brix by noon on Saturday I will be confident.

Wednesday, March 19, 2008

Cap Up This Morning

Yesterday afternoon I mixed the must – which was reading 25° Brix at 69° F – and increased the setpoints to 76° and 79° F. When I mixed the must (#5) I observed the first hints of incipient fermentation – a bit of foam at the edges of the tank.

This morning the cap is fully up at 75° F, though the Pod has not yet registered a drop in sugar. The ferment does not smell at all of ethyl acetate (yet).

According to plan I increased the temperature setpoints again to 81° and 84° F. I also threw in a punchdown (#6). In the Cabernet ferments I left the lid on the Pod throughout. Today I left the lid off the Pinot, and won't put it back on until the ferment is complete.

Chances are that unless I smell ethyl acetate I will inoculate with the RC212 yeast this evening. But if there is evidence of Kloeckera activity I will wait until tomorrow.

Tuesday, March 18, 2008

Waiting For Fermentation

Yesterday evening I raised the temperature setpoints on the Pod to 64° and 67° F as planned, and gave the must a mix (punchdown #4). This morning – still no evidence of fermentation. Increased the setpoints again, to 69° and 72° F.

I'm prepared for the possibility that the ferment won't take off on its own. While I would prefer that it did, I have made great Pinot before that did not start fermenting spontaneously.

I did not have either of the Pinot yeasts I was deciding between in my commercial cache, so yesterday afternoon I picked up a brick of RC212 from Vinquiry. I decided on this yeast over the Assmanshausen (AMH), as the RC212 implants and starts fermenting quickly. By contrast, AMH exhibits a 3-5 day lag before it starts fermenting. Since I am already half way through my planned cuvaison I would rather use the yeast that kicks in fast.

Monday, March 17, 2008

Adding Heat To Start Fermentation

This morning all was fine with the Pod – no evidence of fermentation or spoilage. In fact the aromas above the must had very positive elements of cinnamon, leather and tobacco.

I pushed the temperature setpoints to 60° and 65° F. Then I sat down with my laptop and plotted out my plan for temperature adjustments and punchdowns. If all goes according to plan I will press on Wednesday 3/26. We shall see.

Sunday, March 16, 2008

Pinot Cold Soak Continues

The temperature of the must is holding at about 53° F and there is no evidence that the cap is starting to rise, nor do I smell any spoilage aromas. Tomorrow morning I will start to ramp up the Pod temperature to kick off fermentation.

This cold soak is the most dangerous thing I will attempt in this Pinot trial – dangerous with respect to its potential for ruining the must. I'm doing it to see if I can get away with it in the Pod (and so far I'm happy to say things look good) because I'm sure some other users are going to want to cold soak their Pinot.

I want to differentiate between a facilitated cold soak – one where the must is actively chilled as I am doing now – and a passive "cold soak" where the winemaker is simply waiting for the ferment to take off on its own.

I do not facilitate a cold soak in my commercial Pinot production. I have tasted many facilitated Pinot cold soak trials over the years, and while there are small differences I have not been able to conclude that the wines with extended pre-fermentation maceration at facilitated cold temperatures are any "better" than those where the ferment started on its own, in its own time. For me it is not worth the equipment cost, or the opportunity cost of tying up my Pinot fermenters for longer than necessary, to facilitate an extended cold soak.

What does make a difference is for the ferment to take off on its own – especially if the first yeast to dominate the ferment is a strain of Kloeckera. This yeast starts more quickly than Saccharomyces at lower temperatures, but Kloeckera will rarely ferment to even 12% ethanol. Saccharomyces must finish the ferment.

Things get interesting when Kloeckera takes off and makes ethyl acetate, which Saccharomyces can take up later in the ferment and incorporate into more complex aromatic compounds. In my experience, when the ferment takes off on Kloeckera the finished Pinot has more aromatic "lift" than when Kloeckera is not present.

Kloeckera is truly a "wild" yeast, and as far as I know has never been cultivated – so there is no way to guarantee that it will start any particular ferment. I am thankful when it is present. Whichever yeast starts my Pinots, I inoculate with a selected strain between 22° and 18° Brix to assure that the fermentation has the best chance to go to completion – and that Is what I plan to do in this Pod trial.

What I won't be doing is the post-fermentataion extended maceration that has been so successful for me in the last two Cabernet ferments. In my experience Pinot responds very poorly to post-fermentataion maceration. Most varietals lose a bit of color while developing a more stable lovely red, improved softer and broader tannic structure, and more complex aromas. Pinot loses a lot of color, what remains is more brown than red, and the wine loses aroma but gains harsh tannins that never seem to resolve or soften. Again, this is another example of how Pinot is just difficult and contrary.

Friday, March 14, 2008

Acid Addition To Pinot

We sampled all the available fruit lots for juice analysis a month ago. The lab results on the Roberts Road Pinot were:

Assimilable Nitrogen286mg/L
Disssolved Solids25.6°Brix
Titratable Acidity4.17g/L
Malic Acid1.65g/L
Buffer Capacity31.2mmol/pH unit

Today I added 21.6 grams of tartaric acid (0.5 g/L) dissolved in a liter of water with punchdown #3 (punch #2 was yesterday morning when I added 1.9 g Lallzyme EX or 3g/100kg of fruit). My experiences with the WinePod so far suggest that this half gram addition is a good starting point for arriving at a 3.6-3.7 finished pH. Must temperature was 56° F.

I took in a new sample from the Pod yesterday for analysis. Late today I received the results, for comparison to the sample analyzed earlier

Disssolved Solids26.7°Brix
Titratable Acidity4.59g/L
Malic Acid2.06g/L
Volatile Acidity0.06g/L

The Brix surprised me. I don't think I have andded enough water to ensure a reasonable finished alcohol level.

Thursday, March 13, 2008

2007 Roberts Road Pinot In The Pod

Yesterday was super busy at the winery, so I did not get the chance to put the Pinot I received Monday into the Pod until late afternoon.

The fruit was in perfect condition when I popped the lids off the pails. I dissolved 6 grams of Efferbaktol granules in one liter of water and poured 250 mL of the solution on top of the fruit in each. After I poured the fruit into the Pod I put the last 250 mL on top.

I used 6 g of Efferbaktol (approx. 70 ppm SO2 added) because I was a little nervous about the final V.A. level in the last ferment – the Napa River Ranch Cabernet – where I added just 5 grams (50 ppm SO2).

I am more concerned with pre-inoculation microbial protection with this lot, since I am doing a deliberate cold soak. Once the fruit was in the Pod it was reading 25° Brix at 53.5° F. I turned on automatic temperature control with setpoints at 50° and 52° F – this is the range I want to maintain during the pre-fermentation maceration.

My plan at this time is to give the must a mix once or twice between now and Monday morning, when I will raise the temperature to 60°-65° F to kick off the ferment. Since this is Pinot, once the temperature is up I will punch once a day and wait for the cap to rise on its own before inoculating.

I need to dig in my commercial stash for some yeast to use. In my experience Pinot sensory qualities are more dependent on yeast strain than other varietals. While I love Uvaferm 43 for most Pod ferments because it almost never sticks, I have not been keen on the finished sensory qualities of the very few Pinots where I have used this strain.

The choice of yeast is complicated by the clonal makeup of the Roberts Road Vineyard, which I believe is Swan clone and Dijon 667. I really like how RC212 does with the Dijon clones, but prefer Assmanshausen for the heritage selections like Swan.

You might read this and think "why not just mix the two." Note that it is very poor practice to mix yeast strains. Some yeasts produce "killer" factors that inhibit other strains, and even when K factors are not produced differences in growth kinetics mean that the slowest yeast in any group is unlikely to implant. Mixing strains can be done, but you really have to know your yeasts.

I'm debating on whether or not to add any Lallzyme. I don't use it in my commercial Pinot production because in my experience and opinion the wines yielded by enzyme-treated fruit are coarser on the back of the palate than those where enzyme is not used. I consider this to be specific to Pinot. In fact my experience with enzyme use in other red varietals is the opposite – enzyme-treated fruit produces wines that have a rounder and more integrated tannic structure. To me this is one of the many examples of how Pinot is just difficult and contrary.

That said, the difference between the sensory of Pinots produced with and without enzyme is really "angels dancing on the head of a pin" – important to my commercial production, but the Pod presents a different set of criteria. In my WinePod experiences so far, using enzyme has meant that the must did not overflow the top of the fermenter at the temparature peak, that the press yield was improved, and that the pressed wine clarified faster. These are important condiderations. I think I am going to add some enzyme this morning.

Tuesday, March 11, 2008

2007 Napa River Ranch Cab To Barrel

This morning I racked the Napa River Ranch Cabernet out of the Pod and into the 20 L barrel I had prepped for it. The balance of the wine went to a 3 gallon carboy and two x 1 gallon jugs, with a bit of heavy lees left over to settle before I transfer the clear fraction to a 375 mL bottle.

I was originally planning to rack on Sunday, but the wine was not clear. Even this morning it is nowhere near as clear as the Rancho Sarco Cabernet was when I racked that wine out of the Pod. This difference may be due in part to the use of Lallzyme EXV in the earlier ferment, though there are other factors that could contribute.

The murky wine is not a problem per se, but I expect to eventually see thick lees in the Napa River Ranch Cab and so will want to rack it sooner than I plan to rack the Rancho Sarco.

Monday, March 10, 2008

Received Pinot Noir Fruit

Three pails of 2007 Roberts Road Vineyard Sonoma Coast Pinot Noir showed up on my doorstep today. I'm excited about fermenting Pinot in the Pod, and frankly a bit apprehensive. Pinot is the least forgiving of all the varietals I have ever dealt with, and responds poorly to ham-fisted manipulation – punishes it, in fact. This means I have fewer tools at my disposal to produce a palatable wine.

Tomorrow I will rack the Napa River Ranch Cab out of the Pod and clean it up for the Pinot ferment. Just to be trendy, I am likely to get the Pinot into the Pod while it is still quite cold (probably on Wednesday) and give it a bit of deliberate "cold soak" before the ferment.

Sunday, March 9, 2008

Ready For Racking

Today I added 5 grams of Efferbaktol granules (2 grams SO2, giving about 50 ppm) to the Napa River Ranch Cabernet in the Pod, and turned off the temperature control.

I changed the water in the new barrel I'm soaking up for this wine for the last time. I was a bit disappointed when a relatively large amount of wheat paste came out of the barrel in small chunks when I emptied the third fill. Wheat paste is used in the cooperage to seal the barrel heads into croze, and sometimes its use is a bit sloppy.

I don't have strong evidence that excess wheat paste in new barrels is problematic, but it is no secret that new barrels are more likely to grow Brettanomyces than old ones.

Another issue for some might be sensitivity to wheat gluten. Online literature citations suggest that wheat gluten can be used as a fining agent for wine (indicating that it precipitates well) and the FDA has recognized its use as GRAS, but gluten protein is soluble at pH 2.0 and may be at least slightly soluble at wine pH and alcohol content. TTB has proposed rulemaking for allergen labeling in concordance with the Food Allergen Labeling and Consumer Protection Act of 2004 that would mandate listing on the packaging any wheat products used in wine processing.

For all these reasons, for the last five years I have been asking my barrel suppliers to use the minimum necessary paste to assemble my commercial cooperage.

Friday, March 7, 2008

Barrel Prep & ML Done!

Wednesday I started prepping another new 20 L French oak barrel for the Napa River Cabernet. As before for the Rancho Sarco Cabernet barrel, this one will get four changes of hot (150° F) water over as many days before I rack wine into it. Today I gave it its third fill, where I added a pound of kosher salt to the water as before.

I just received the results of the malic acid analysis from the sample I took to Vinquiry yesterday, and the fermentation is done (0.07 g/L). Tonight I will add SO2 to the wine in the Pod and turn off the temparature control. Sunday I will rack the Napa River Cabernet out of the Pod and into the barrel and carboys.

Wednesday, March 5, 2008

Pressing the Napa River Ranch Cabernet

This morning I pressed off the 2007 Napa River Ranch Cabernet, after 25 days of cuvaison. I pretty much duplicated the protocol I followed to press the 2007 Rancho Sarco Cabernet last month.

The only difference this iteration was that I followed and documented a more rigorous pressing program. As before I started the pressing in automatic heavy press mode. Once this mode tripped off at max pressure I switched to manual press mode and went to full press every thirty seconds for ten cycles. I followed this with five trips to max pressure every 60 seconds for five cycles, and then five more cycles at 2 minute intervals. Last I went to max pressure every four minutes for ten cycles, giving a total manual program time of 62 minutes.

I could have pressed more – I never got to the point in this pressing where the max pressure hit at motor startup – but got bored with it. Also suggesting there was more pressing to be done, the yield was only 10.6 gallons where the Rancho Sarco pressing yielded 10.9 gallons. The difference may have been due to more water added to the Rancho Sarco ferment with the various additions I made.

But the enzyme I used with the Rancho Sarco also may have had an effect, or effects. For certain the must in the prior ferment did not overflow the top of the Pod as it did with the Napa River fruit. And it is possible that using the enzyme allowed more efficient pressing of the Rancho Sarco must, since with a casual manual program I was able to fully compress the cake, where with this more determined pressing the cake remained spongy.
Bottom line – I believe that I want to use enzyme in my future Cabernet ferments in the WinePod (1.3 grams of Lallzyme EXV or 1.9 grams of Lallzyme EX). In fact, I would recommend Lallzyme for all red grapes except Pinot Noir (where, in my experience, enzyme use actually yields a more tannic wine).

After racking the wine out of the Pod into pails and returning it to the Pod to complete malolactic, I moved the temperature setpoints to 70° and 72° F.

Tuesday, March 4, 2008

Bottled The 2006 Windsor Oaks Cabernet

Today I bottled the 2006 Windsor Oaks Chalk Hill Appellation Cabernet, which I fermented last July. The wine was fermented on French oak cubes and has been aging in a 7 gallon glass carboy since pressing.

Compared to wines aged in barrel, wines aged in glass don't receive the slow beneficial oxidation the barrel environment affords. In glass aging, oxygen is introduced into the wine when it is racked from carboy to carboy. This wine has had five rackings: the first after pressing, two racks during aging, one rack this morning, and then the final racking into bottle. I would not have racked a barrel-aged wine this often over 7 months – maybe twice.

Over the course of aging the wine I made three SO2 additions: one big one after the completion of malolactic, and two more small maintenance additions during aging. I checked the level of free SO2 in the wine this morning (using the aeration/oxidation apparatus I keep at the winery) and found that it was 29-30 ppm. I ordinarily want to bottle with a free SO2 of 25-30 ppm, so I chose not to make an addition today.

I don't get stressed out over SO2 really, as I have found that its use is at best an inexact science. The A/O measurement method has a real world precision of ±2-3 ppm, and nailing a precise addition is nearly impossible for a number of reasons. There is a school of thought that favors tying the desirable SO2 level to the wine pH, but I reject this approach for red wines in particular, as it discounts the protective effect of the wine tannins. I would sum up my attitude as "some SO2 is better than none, and too much is bad".

Provina president Greg Snell provided me with 375 mL bottles (rather than 750 mL) so he can have more samples to give away. To seal them I used a bag of high quality 2-inch corks leftover from a commercial bottling. These corks are a couple of years old, but the bag still smelled strongly of SO2 when I opened it, as if they had just been packed recently – I'm going to assume that the moisture content of the corks also has stayed reasonably constant (the moisture level in the corks needs to be 4%-6% for them to seal properly).

I put together a 3/8-inch copper pipe with a length of 3/8-inch Tygon tubing to make a racking hose, and this is what I used to transfer the wine from the carboy to the bottles. My goal was to leave about 1/8-inch of headspace between the top of the wine and the cork. I was not obsessive about an exact fill height, just eyeballing the level. As I expected, the corker drove some of the corks deeper than others – this, combined with the small variation in fill levels, meant that some bottles have no headspace at all.

Zero headspace is not a "best practice". The wine temperature is currently about 58° F. As it warms up, the bottles with no headspace are going to push out the cork – or leak. In an ideal world I would have warmed the wine up to 68°-70° F before bottling and maintained 1/8-1/4 inch headspace for the 375 mL bottle size. For a 750 mL bottle I would leave 1/4-1/2 inch headspace. I'm recommending that the samples with zero headspace get used first.

I chose not to worry about a couple of other things for this bottling: I did not wash or rinse the bottles, nor did I sparge them with inert gas before filling them. The former was a judgment call on my part – my calculation of the cost/benefit told me to not waste the time. The latter was more deliberate – I chose not to sparge because the wine could use some oxygen still.

My final yield was seventy 375 mL bottles. Note that I expect to get at least fifty 750 mL bottles (or one hundred 375 mL) from my more recent ferments, due to the improved pressing efficiency of the current version of the WinePod.

I did not set out to make a wine according to any particular style, but to simply do the best I could with the grapes and equipment to hand. IMO it turned out really well. The 2006 Windsor Oaks Cabernet ended up being a fruit-forward wine, with good varietal character, subtle oak and a great tannin/acid structure.