More Butter, Please; Caveats with Pectic Enzymes; and Wonky Grape Numbers

Q I’d like to create a more “buttery” tasting Chardonnay. Through some research it appears that malolactic bacteria (MLB) is usually used but I’m not sure where to get this or if there is another way to achieve the same result. What are your thoughts on this?

Lou Anne
Belle River, Ontario

A Indeed, that flavor you’re after is primarily caused by the malolactic bacteria, which impart that buttery, dairy, or creamy taste in many Chardonnays. This is because these bacteria, depending on the strain, can produce a lot of a compound called diacetyl, which is a natural byproduct of their malic acid metabolism. Diacetyl really does smell like butter and is purposely produced in the commercial food industry to flavor, you guessed it, movie theater popcorn along with crackers, baked goods, and other things that need a little buttery kick to mimic the real thing.

Photo courtesy of Shutterstock.com

How to get more of it naturally into your wine? Choose a malolactic (ML) strain like Lallemand’s PN4 and Beta, both of which are sold by Scott Laboratories in the United States. My connections at Scott Labs tell me that PN4 is “creamier” while Beta will come across as more “buttery.” Choose wisely and you’ll be rewarded with higher-than-usual levels of the buttery goodness. Not all ML cultures are alike, and these two are examples of those which have been meticulously bred to produce diacetyl under the right conditions.

Of course, it couldn’t be as easy as simply sprinkling a magic packet on top of your newly fermented Chardonnay. It’s also critical to take a 360-degree view and provide the right overall conditions for buttery success.

Here’s how to optimize your chances for a high-butter Chardonnay using a ML strain like those mentioned earlier:

  • Don’t co-inoculate: ML bacteria and primary fermentation yeast (Saccharomyces cerevisiae) are sometimes added together in order to speed up the completion of the malolactic fermentation. Yeast can break down diacetyl so this recent trend of completing both fermentations simultaneously will result in less-than-optimal levels of diacetyl.
  • Minimize lees contact time from the primary fermentation: The shorter the contact time with yeast lees the higher the diacetyl production. After primary fermentation is over let the yeast settle for a few days, rack or even do a rough filtration to exclude them before you inoculate with your ML culture.
  • Go low and slow: The slower the ML fermentation, the higher the production of diacetyl. To that end, keeping temperatures moderate (55–60 °F/13–16 °C) will allow the fermentation to continue but not too rapidly. If your Chardonnay has a higher pH the ML fermentation will progress more rapidly as well. I recommend having Chardonnay start ML fermentation under 3.55 pH. Adjust with tartaric if needed.
  • Use a minimal inoculation: Always follow the manufacturer’s instructions but going in at the lower end of the recommended dose rate will result in a slower ML fermentation and therefore a higher level of diacetyl production.
  • Stir the lees: Stirring lees (though you shouldn’t have too much sludge, as hopefully you removed most of it first) during ML fermentation keeps the conditions from becoming reductive, which can repress the production of diacetyl. Stirring lees after the ML fermentation is complete is also a way to enhance mouthfeel by releasing mannoproteins and other “creamy”-feeling compounds into the wine.
  • Add SO2 normally: Once the ML fermentation is complete and you adjust your free SO2 to around 25 ppm or so, the diacetyl may seem to disappear. This is because SO2 binds to diacetyl in a reversible reaction; over time the diacetyl will be released back into the wine and your buttery goodness will return. It’s important to use SO2 if you want to foster diacetyl production because it inhibits spoilage yeast and bacteria activity, which can reduce it.
  • Age on oak: I find that the oak choice you make can really enhance the buttery, creamy characteristics of the final wine. Oak does not contribute diacetyl in any way, but the supporting aromas and flavors of vanilla, caramel, and crème brûlée can really boost and flesh out the bare diacetyl notes. I’d be willing to bet your favorite Chardonnay isn’t just about diacetyl but also about a host of these supporting flavors and aromas. You don’t have to invest in barrels, either, as there are plenty of oak pieces and chips on the market, even some specifically toasted and blended to contribute certain overlaying finishes to wines. Check out Radoux’s Pronektar line or the precision chips of Vivelys’ Boisé Origine. Both are high-quality products that don’t taste “chippy” in the finished wines and only take about two months or so to fully extract.

Don’t like oaky, butter-bomb Chardonnays? You’re in luck. For those readers who like a fruit-driven Chardonnay and abhor the buttery characteristics of diacetyl, do the opposite of the above if you want to minimize its role in your wine program.

Q I’ve just read that using pectic enzyme can result in faster maturity in some wines and that sometimes such wines decline faster than untreated wines. Should I avoid using it or not worry about using it if I am to drink my wines within 1–3 years? On average how much time can it take for such wines to start declining and for someone to start noticing? I’ve always used it for my red wines. if I stop am I likely to come across haze issues?

Robert St-Jean
Cantley, Quebec

A To quote one of my vineyard colleagues who always likes to give multiple sides to every answer, “It depends” (thanks, Rich). And so it is with pectic enzymes in winemaking. Pectic enzymes are proteins that can be added to wines at different stages to achieve many different results: To increase juice yields at the press, to help color extraction, and to result in better settling. In the case of fruit or country wines, pectic enzymes are a necessary ingredient in your winemaking arsenal as it’s almost impossible to get clear, bright, and settled fruit wines without using them.

Since you mentioned red wines above, I’m assuming that you’re using wine grapes and not high-pectin fruit like black currants or raspberries. If you’re making all-grape wine the choice to use pectic enzymes or not will depend on your starting material and on your experience with these particular grapes, if you’ve used them more than once. Pectic enzymes, unlike say, sulfur dioxide or oak barrels or chips, are quite low on my list of “necessary” winemaking ingredients for traditional red winemaking. When added at the crusher these enzymes can help in improved color stability and rounder mouthfeel as they break open the grape skin cells and “digest” the larger pectin molecules. I could see this being beneficial to lower-color varieties like Pinot Noir and indeed this is the one area where I will sometimes use pectic enzymes, albeit at a low dose, in my own winemaking.

If you’re willing to be of the ‘no wine before its time’ school, and you’re willing to be patient, then I don’t see the point in using pectic enzymes to hurry things along.

Does using pectic enzymes result in faster maturity and then a subsequent early decline of the wine over time? Insofar as it improves mouthfeel and roundness, I could see how it could be interpreted as having that effect. I’m not sure it’s so much about advancing aging as it is making wine friendlier a little earlier. If you’re willing to be of the “no wine before its time” school, and you’re willing to be patient, then I don’t see the point in using pectic enzymes to hurry things along. There are plenty of ways to build mouthfeel like lees stirring during aging (works on white as well as red wines) and the smoothness and roundness it’ll pick up from aging in barrel or with oak chips, blocks, or segments.

That statement, “it depends” comes into play again because your starting material and dose will dictate the outcome. Big, tannic monsters like Cabernet Franc or Petit Verdot would roll over a small dose of pectic enzyme without blinking, and I would argue don’t really need it (plenty of color and mouthfeel precursors already) as long as you’ve got enough time to age the big tannins into smoothness in a barrel or with some oak pieces. The over-addition of any fining agent can really strip a wine and I could see that if you started with a lighter-bodied Pinot Noir batch and used a high dose of pectic enzyme in the fermenter. You might fine too much of the character right out of such a wine. At the very least, too much pectic enzyme will turn your red must to mush in the fermenter resulting in a messy nightmare as you try to press.

Do you really need to use pectic enzyme in red winemaking? In my own winemaking I tend not to as I’ve never had a problem with pectin hazes. It’s indispensable for fruit wines but Vitis vinifera tend not to give me those issues. Like I said earlier, the only time I use enzymes in red winemaking is with some lighter-colored wines like a Pinot Noir. You may have heard me say in the past that “time is the best fining agent.” This is true with regards to just about any red wine. Red grapes don’t typically carry a high pectin load so using an enzyme to remove it just seems like a bit of a waste of time and money to me.

Q I have a Petite Sirah in secondary with the following characteristics:

  • 23 L (6 gal.) of juice (2020 vintage) from the same supplier as I have used for 6 years
  • Source of juice is California
  • Brix: 21.1 (lowest I have ever had)
  • pH: 4.1 (highest I have ever had)
  • Titratable Acidity (TA): 2.5 g/L
  • Free SO2: about 40 mg/L
  • Temperature: 71 °F (22 °C)

I adjusted the TA by adding tartaric acid and achieved a TA of 7.5 g/L with a pH of 3.2. I added yeast (BM45) with nutrient. Fermentation proceeded normally. On day 7 when Brix was 2 I added the malolactic bacteria. On day 9, when Brix was 0.7 I racked the wine off the gross lees. A slow fermentation continued for the next 14 days. I did not take any measurements during this time. But on day 24 I did measure the following:

  • Brix: 0.0
  • pH: 3.2
  • TA: >10 g/L (probably 12)
  • Malolactic fermentation (MLF) is not completed

I didn’t measure FSO2 as the wine had only been racked once up to this time and had always been topped off. I racked the wine off the fine lees and that is where it sits today. The wine tastes very tart but there isn’t any noticeable odor. Apparently, what I thought was the slow tail end of fermentation was actually CO2 forming. Can you please advise me on any steps that I can take to salvage this wine? And what’s your best guess on how this came about in the first place?

John Regina
Vernon, Connecticut

A Well, your grape or juice source really put you in a bind. Those are some of the most unbalanced initial numbers I’ve ever seen, and I would seriously consider getting your juice from another source next year. Numbers like that — with the acid being so low and the Brix simultaneously being low may be, I hate to say, indicative of dilution with water. I really hate to propose that someone would be that unscrupulous and certainly don’t want to get anyone in trouble, but you’d expect a 4.1 pH for a red grape to correspond to Brixes being at least above 25 if not closer to 28. Like I said — whatever the cause, those are very unusual, unbalanced numbers and certainly didn’t give your project much of a starting chance.

You did the right thing by trying to add acid to make up for that dangerously high pH of 4.1. Targeting a TA of 7 isn’t a bad thought, though it’s a little high for my tastes and because of the buffering capacity of your juice, landed you with a really low pH. 3.2 is very low for a red wine and, post- adjustment with a pH of 3.2, there’s very little chance a malolactic fermentation is going to be able to happen to completion.

I think this is where your problem lies now because it’s really unlikely that your ML fermentation will happen at all. Where did the 10 g/L total acidity come from? There’s no logical reason for a TA to go up that dramatically unless the acid you added in the original hit wasn’t well measured out and also wasn’t well mixed in when you sampled and got that 7.5. This is one of the reasons why I suggest in my book, The Winemaker’s Answer Book, that such large additions are best made in at least two stages, so that proper mixing can happen.

Salvage? It’s hard to say what I would recommend because this poor wine has been through so much already and it seems to me just didn’t have a very good start in life. You could try adding potassium bicarbonate to raise the pH. I would start with 0.4 g/L, dissolve the powder in a small amount of water, then mix it in well with your wine. This should increase the pH maybe up to 3.3–3.4 . . . measure pH again and see where it goes. It’s impossible to predict the exact effect because the impact on pH with any acid addition or acid neutralization isn’t linear and is dependent upon a myriad of factors within each wine, sadly few of which are measurable. For this reason, when dealing with pH or TA shifts I always try to do bench trials on small samples first, measure and taste the results, and only scale-up to cellar batch-size after you know what the result will be.

With a pH above 3.2 you have a much better chance of at least being able to complete the ML fermentation. Getting the wine racked, SO2’d, and protected from spoilage will help it come to a point where you can begin to consider what to do with it. If you still want to try to achieve a red wine style, you might want to try de-acidifying more if further adjustment is needed. Because I suspect you’ve not got much in the way of ripe tannin, fruit, or mouthfeel, you can try to build those up using oak chips or some of the liquid oak tannins that have been launched in the marketplace in the last five years or so. Sadly, these additives and aging adjuncts can only take you so far as I suspect that your original material was compromised from the beginning. It’s impossible to replicate the richness and density, especially of a big red grape like a Petite Sirah, when there’s nothing there to begin with.

To improve the situation in the future, I think you really should consider changing your raw material sources. I also grow grapes and if I had delivered grapes with those numbers to a client, they could’ve refused to take them, or could’ve demanded a discount, as long as our contract had quality stipulations. Typically, grape contracts will have provisions that say the grapes will be above 24 °Brix or something along those lines. I know that the world of home winemaking is a little different than a commercial operation but you shouldn’t have to stand for poor quality, especially if it’s something you’ve paid good money for. Mother Nature is a fickle mistress and we all know that batches vary from year-to-year and we winemakers have enough challenges already, but it’s really a shame that Petite Sirah was marketed with initial numbers like that.