Pre-ferment jitters - please respond ASAP

Hi everyone,

Sorry to plague you with yet more questions. Here's the situation.

Have 20 gallons of Pinot Noir must that's been cold-soaking for 72 hours. I'm almost ready to pitch the yeast starter, but took a few final pH and TA readings, and wanted to run it by everyone.

I understand that potassium extracted from skins tends to raise pH, especially towards the end of a cold soak.

I was unable to take an initial pH reading right after crush.

The readings this evening were: TA .60%, pH 3.95.

I added a solution of Tartaric acid at the rate of 3g/L and the new pH is about 3.82. I haven't done a TA test.

From what I've read, winemaking in the 3.7-3.9 range isn't unheard of,

and tends to make more of a "big red" Pinot. I doubt this will last more than 3 years, especially if it's good, so I'm not too concerned about making a wine that will last 8 years.

What I simply want to know is -- should I stop adding Tartaric where it's at?

Would it be worthwhile to run one more TA test?

OR...

Should I just pitch the starter and go for it?

Thanks,

David

Reply to
David
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I went ahead and have added more tartaric acid. From my calculations, the must should now be around pH 3.66 or so, with about TA .77%-.8%. I'm not worried about the TA, as I can always cold stabilize it later on if I want to drop the acidity. The major thing was to have pH lower than the 3.95 it actually started off at (blast that cold soak!).

David

Reply to
David

Sounds like a reasonable approach to me.. How many gms or ozs of Tartaric acid did you actually add the second time..?

Reply to
Jim Hall

I assume you're planning to put wine through Malolactic fermentation also to stabilize wine and help bring TA back down..

Reply to
Jim Hall

Hi Jim,

For this second round, 61 total grams for the 20 gallons (~3g/Gallon, or about .8g/L).

Total Tartaric added was about 1.6g/L

David

Reply to
David

Absolutely. I'm looking forward to a *good* Malo this time.

2 years ago got really bad advice from a brew supply shop - one guy handed me a Malo culture, and when I came back for more acid, the other guy handed me a blended acid pack. LOVE how citric and malo *don'* combine well. :)

Cheers,

David

p.s. 2 hours after pitching the starter, ferment is already underway. WELL underway.

Reply to
David

David wrote "I went ahead and have added more tartaric acid. From my calculations, the must should now be around pH 3.66 or so, with about TA .77%-.8%."

David, did you actually take a pH reading? Ideally your starting pH would be low enough so pH after malo-lactic fermentation is reasonable. Malo-lactic fermentation will raise pH by about 0.25 pH units.

"For this second round, 61 total grams for the 20 gallons (~3g/Gallon, or about .8g/L). Total Tartaric added was about 1.6g/L"

If I follow your acid additions correctly you first added 3.0 grams per liter tartaric acid to 20 gallons of juice. This works out to 227 grams of acid. Then you added 61 additional grams. A total of 288 grams acid added to 20 gallons (75.7 liters) of juice or 3.8 grams/liter. Add this to your starting 6.0 grams/liter acid and you may have an acid content of 9.8 grams/liter or 0.98%TA.

How does the juice taste?

Bill Frazier Olathe, Kansas USA

Reply to
William Frazier

Hi Bill,

My initial calculations were incorrect.

Part of the problem is that my first TA test was a bit inconclusive. It was done within 24 hours of intial crush, but by that time, colors were already clouding up the must, making it difficult to tell when I'd found the right TA level. Somewhere between .55% and .65%. It was pretty hard to determine exactly when the test sample turned gray, and not just a "tint" of gray.

Another aspect is that I have two vats of must. One with about 16 gallons, the other with about 5 or 6 gallons. Last night, the larger vat had much higher pH, because of more potassium being leached out of the extra pomace, while the smaller vat had consistenly lower pH (by .15!) due to less pomace.

My challenge was to calculate the proper amount of Tartartic to add, understanding the smaller vat would need proportionately less than the larger, in order to achieve balance between the two. But then, I considered the fact that throughout ferment, the two vats will develop their own unique pH anyway, since there is more pomace in the larger vat, etc. So I ended up figuring that if the smaller vat were to have lower pH, and the larger a higher pH, it might make for a bit of an interesting blend once primary was done. And, even if the larger vat ended up with a much higher pH than the smaller vat, by blending the two after primary, I'd achieve a bit of balance.

So. I added a total of 30.4 grams Tartaric acid to the smaller vat, about 6grams per gallon. This resulted in more or less a pH of 3.5, down from the 3.75. It was difficult to get an accurate read, as the acid was not evenly distributed throughout the solution, even after stirring for many minutes. I took 15 different samples, ranging from

3.3 to 3.6, 3.4 to 3.7, and in the end, averaged them all out to about 3.5. Depending on the accuracy of the TA test, this would put TA now at .8% to .85%, and while by itself, that might a bit high, it should balance out when blended with the larger vat.

To the larger vat, I added a total of 136 grams of Tartaric acid, about

8.5grams per gallon. This reduced pH from 3.95 (it had gotten pretty high, even 4.00 in some portions of the vat) down to 3.8, and increased TA by .21%, to .76% to .81% (again, depending on the actual, initial TA test).

I then averaged these out.

6gal. @ pH 3.5 + 16gal. @ pH 3.8 = 22 gal. @ pH 3.71

6gal. @ TA .82% (avg. of .8 to .85) + 16 gal. @ TA .78% (avg. of .76 to .81) = TA .79%

These figures look fine to me. Even after Malo, if pH is boosted by .25, a final of about 3.9 should be fine, given the wine isn't intended for more than a few years' ageing.

Fermentation is just 12 hours in, so if I still need to boost Tartaric a bit more, I could... I'm just questioning the need for it.

Thanks again for all your helpful input.

David

p.s. the juice tastes great. I can taste the acid through the sweetness, so I think overall it's balanced.

William Frazier wrote:

Reply to
David

We'll have to get total grams for first addition from Dave to find out. My calc's indicate he's using 10gal or 38 liters as base for his adjustments. If that's the case then first addition would have been closer to 114 g Tartaric. Still a lot.

Second addition... 61 g Tartaric/("1.6g/L") = 38.13 Liters of estimated wine

First addition.. 3 g/l Tartaric x 38.13 L = 114.13 g Tartaric

Total Tartaric.. 61 g + 114.13 g = 175.13 g.. Still a lot

I would figure he should get about 55 or 56 liters of wine at press. Say 55 liters

175.13g total addition /55 liters of wine = 3.19 gms/liter or 0.32 increase in TA.. or new total of 9.19 g/L

Reply to
Jim Hall

Oh, ok.. So if you had 200 lbs of grapes initially. That would translate into about 55 + liters of wine (using my pressing calc) and you added 136 gms of Tartaric or

136g/55 L = an increase in TA for the batch of 2.4 g/l at the most.

We'll have to wait and see how it comes out.. If your readings aren't consistent you may need a new pH probe. When you titrate, you can use pH meter to measure end point instead of color. Just add Sodium Hydroxide until pH hits 8.2.. In the meantime, I wouldn't worry about, enjoy fermenting your wine and the new perfumed air. Life is good..

-Jim

Reply to
Jim Hall

D'OH! Of course! I should have thought of that. :(

pH meter is accurate. My faith in reading the TA test results, not so much. :)

Thanks,

David

Reply to
David

Is this really the case in these situations? I would expect that in (over) ripe grapes there wouldn't be that much malic acid left, so a pH increase of 0.25 due just to MLF seems too high. Never measured this though so have not data to back this up, just a theory.

Pp

Reply to
pp

Pp, the 0.2 to 0.25 pH unit increase is the pH change I've seen following malo-lactic fermentation over the years in my grapes. Bill Frazier Olathe, Kansas USA

Reply to
William Frazier

Well... I had 223 pounds of grapes initially. I'm figuring about 10% of that weight was lost to destemming, so yeah, about 200 pounds of must. It's hard to calculate, precisely, because while I intended to carefully mark 1-gallon increments along all the fermenters, *yet again*, I forgot. :)

I've concluded that while my TA may now be around .9 to .95 averaged between the two vats (and with pH of what.. 3.75? 3.8? -- yes a bit high), I tasted it, and the must in both vats tastes fantastic. I would rather push it too acidic and let it reduce through cold stabilizing, tartaric settling, or simply age.

I do admit, I was a bit concerned about high TA and pH, but really, I think the pH is due to Potassium... in punching the cap, using a tool I designed from a stainless steel screw, oak dowel, and oak shelf (details available if you want), I may have actually been doing a bit of *pressing* as well -- which may have helped boost that pH from extra leaching of Potassium. I'm not too worried about that though, as cold stabilizing will help.

As for the grapes themselves, a few were over-ripe (some were Brix

27!!) but the average of the must originally was 23.5. So I think there's still plenty of Malic waiting to be converted over during Malo.

Sorry if I'm rambling... just a bit excited right now with this Pinot...

Thanks again for everyone's help,

David

Reply to
David

Keep track of how many gallons of wine you press, then you will have a ratio to use in the future for estimating amount of pressed wine for your future batches of Pinot. Different people get different amounts based on kind of press they use and how hard and long they press. Also grape condition and type may impact on results. My yield typically is around 13.64 lbs of grapes (gross weight including stems) to a gallon of pressed wine. So in your case.. 223/13.64 or 16.35 gal of pressed wine.. When adding Tartaric, I found that if I add half of what I think I need and then retest the next day, I can determine if my calc is right. If acid level comes up more or less than expected then I'll adjust second addition to compensate. Good luck with your wine and post your pH and TA after fermentations are completed. Curious to see how it comes out..

Never made a Pinot Noir. I only have visions of a tall skinny, bearded frenchman stomping down the cap in a large vat of fermenting pinot grapes in his red speedo underwear at a small winery run by two women in Burgundy region of France. It was a vineyard and winery tour, believe it or not, many of the women, including my wife, appeared to enjoy that part of the tour the best..

Reply to
Jim Hall

Hi Jim (and everyone),

Quick note - saw your calc's and needed to correct:

I'd added 3 g/GALLON, not liter. Sorry if my notes confused that earlier.

Now, on to the main event... the ferment. :)

I wanted to fill you all in on the last 24 hours.

Yesterday evening, the wine dropped by S.G. .03 in just 15 hours! It was time to press, so I drove by the local wine supply shop and snagged one today.

I had a very enjoyable afternoon. A friend came over and helped operate the press. I'd tried getting a hold of a few wooden palettes from a Costco or grocery store, but came up empty-handed. So, I made use of the spare 2x4's and 2x10's to construct my own press stand. It raises the press about 10 inches off the ground, is very stable, and has an open area for carboys and other collectors to fit below the press spout. Of course, we made use of a funnel and carefully held the carboys at an angle so as not to splash any of the wine.

I scooped small bucketfuls (about 1-quart each), one at a time, into the bottom of the press basket, and allowed the free run to pour off. We easily filled about 75% of the volume of the carboys without any pressing. As the skins would pile up in four- or five-inch thick sections I'd hand press them down before piling on more fresh scoops from the fermentor. By the time we'd run through all of the wine, and I'd carefully hand-pressed the skins, we'd filled more than 13 gallons' worth into a 6.5- and a 7-gallon carboy, plus about 1/5 of a 5-gallon carboy, for a total of about 14 gallons of free run.

It was really interesting to note how very little remained to press using hand-cranked ratchet, but we went for it, and got another, oh, 2 gallons from that. I'd say the longest part of the process was building the platform, sanitizing everything in the garage, arranging all the objects with ample sanitized surfaces (and buckets) around us so we could drop things if we needed to swap out a carboy, with a simple, plastic beer pitcher to catch any of the free run that poured through the funnel while one of us grabbed a new/empty carboy, etc. etc. The actual pressing went fairly quickly.

I'd say there are now at least 17 gallons of wine amongs the three carboys. The largest, the 6 and 6.5, actually hold closer to 6.5 and 7 gallons each, respectively, and the 5-gallon holds more like 5.5 gallons, so it's a little difficult to tell exactly how much is really in them. Plus, there is the issue of the lees. Heavy, thick sediment at the bottom of each carboy.

I'm going to let the carboys sit for a day or two and most likely rack them into fresh ones off the lees. I am presuming the majority of the settlement is gross lees, which I understand can make the wine go bad. I'll know more when I see the carboys in the morning. The good news is that the majority of the pomace stayed behind, and overall, the carboys are quite clear already.

A few test samples to share...

ph 3.45 TA .8

This has improved quite a bit from immediately before the ferment. It looks like this would be a good contender for MLF. If I am going to rack off the gross lees, I'll do that first and then pitch the MLF. However, I've read that the lees can provide some sustenance for the MLF bacteria... Any thoughts on this?

Thanks,

David

Reply to
David

Pp makes a good point. The riper the grapes the more likely it is that more malic acid has been respired, leaving less substrate for MLF. Additionally, there are many other compunds influencing pH besides malic acid. As another data point, I've been using California grapes harvested at 24 - 27 B for the past 3 years. Typically, I see no more than a 0.05 - 0.1 point change in pH after completion. For me, MLF has been much more about microbial stability than style for big reds

RD

William Frazier wrote:

Reply to
RD

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