Why does Centralas’s HELLO, OLD FRIEND white wine taste the way it does?

Our 2021 white wine is made from the grape Fiano, grown in a vineyard that was farmed organically in Hemet, California. These facts create some of the most dominant flavors of the wine.

Fiano is a white grape (really a yellow/green grape) whose home in the Old World is Campania, Italy. It is a grape that was probably selected over the centuries to be grown there because, in addition to complex and perfume-like aromas, it retains its acidity and freshness even in the heat of Southern Italy.

I know this is why the owner of Tranquil Heart Vineyard chose to grow it in Hemet, whose heat makes Italy’s heat feel refreshing. I mean it gets really hot in Hemet. Because of this intense heat, I chose to pick the grapes on the early side, aiming for 20-22 brix, despite their natural ability to retain acidity, because, as a general rule, as grapes ripen they increase in sugar content (brix) while they diminish in acidity.

The grapes came in at approximately 20 brix and 3.3 pH, pretty close to what I wanted.

When I say “came in,” what I mean is that I picked up a ton of grapes in Hemet, drove them to our production facility in Moorpark, crushed them and siphoned the juice to tank to settle. After settling approximately 24 hours, we measured the brix and pH, then siphoned the clear juice off the sediment to two neutral barrels (and a carboy or two).

I was mildly disappointed that the brix were so low, fearing that the grapes hadn’t achieved full flavor development before picking. Tasting the finished wine now, I’m really glad they were what they were. Any more ripeness would have led to a very big and flabby white.

Once the wine was in barrel, I just allowed the wine to do its thang. That’s technical speak for, “I did nothing.” Natural yeasts on the grapes or ambient in the winery completed the fermentation.

Doing nothing actually has several consequences to the flavor of the finished wine. First of all, when you don’t add yeast, multiple strains of “wild” yeast and bacteria begin the fermentation, adding their own unique characteristics until the next dominant strain that can withstand higher alcohol and higher temperatures take over the fermentation, until finally the big guns – Saccharomyces cerevisiae – take over and finish the alcoholic fermentation.

This ecological succession on a micro-biological scale creates complexity in the aromas and textures of a finished wine.

Fiano is already know to have varietal characteristics of honeydew, hazelnut, Asian pear, orange peel, and pine. But a wild fermentation can add to this many tertiary flavors.

There is one aroma and texture you may pick up on HELLO, OLD FRIEND that is not from fermentation… or at least not from what is known as primary fermentation (the conversion of sugar to alcohol and CO2). That flavor is what you may sense as buttery-ness, buttered popcorn, butter fried nuts and a creamy texture.

Butter in wine, like in a big buttery Chardonnay, comes from a secondary fermentation, a process known as malo-lactic fermentation (MLF).

When tart fresh grapes come into the winery they contain malic acid. Malic acid in wine is unstable, because the grapes also come in with lactic acid bacteria (LAB) which eat the malic acid and convert it to lactic acid and CO2. The most common LAB in wine is Oenococcus oeni.

Malic acid – from malus or apple – is the sharper acidity you taste when you bite into a green apple. Lactic acid – from its association with milk – lends a softer, creamier texture to the wine.

If you do nothing, as we do, the natural LABs will naturally convert the sharper malic acid in the wine into the creamy lactic acid, and will also produce a compound called diacetyl. Diacetyl is the compound responsible for the buttery flavors and aromas in, especially, white wines like Chardonnay and Fiano.

Now not all natural process are equal, as different strains of LABs under different conditions may produce more or less diacetyl. Thus there can be variation in the amount of buttery-ness from year to year in a white wine even when it is made from the same grapes and in the same way.

The only way to prevent MLF is to intervene in some pretty extreme ways. You have to add extra sulfites, chill the wine, and then sterile filter it. This first prevents the process from starting, and then removes the LABs that would cause it to happen.

You can also inoculate the wine with a cultured strain of LAB known to produce low levels of diacetyl. This would stabilize the wine while giving you a low level of buttery-ness, but again is a level of manipulation I find unnecessary. And I very much enjoy the level that occurred naturally in HELLO, OLD FRIEND.

This whole concern about MLF is because you don’t want it to happen after you’ve bottled the wine. You want to ensure complete MLF has happened in the winery, or you want to take the necessary steps to prevent it from ever happening, because if it happens after bottling, you’ll end up with an unintentionally spritzy wine – as the CO2 produced by MLF is trapped in the bottle and absorbed into the wine – and often some strange aromas that would have blown off if MLF happened outside of a bottle. Also the pressure from that CO2 production in bottle might push the corks out partially.*

New oak barrels are often thought to cause the buttery-ness you taste in wines like Chardonnay, but now you know the real reason: diacetyl from MLF.

New oak barrels do contribute a richness and concentration, and sometimes a softer, arguably creamier, texture. But the aroma/flavor profile of new oak in white wines is more along the lines of vanilla, toasted coconut, caramel and/or butterscotch, and even a maple-bacon smokiness. (Given this list of flavors, in addition to buttery-ness, I don’t know why an oaked chardonnay isn’t a more common breakfast item.)

Regardless, even if new oak could contribute to the buttery aromas/flavors you may detect on HELLO, OLD FRIEND, I didn’t use any. I only used barrels that had been used enough times to impart no flavors (though they still contributed to the texture of the wine).

Now, going back to the brix level. At 20 brix, the wine I made previously from grapes from Santa Barbara County would end up with less than 12% alcohol. So I was caught off guard when HELLO, OLD FRIEND finished at over 13% alcohol. The alcohol conversion rate went from a factor of .59 to a factor of .66 in our new facility with non-Santa Barbara grapes, and I honestly don’t know why that is. I do know that we’d have to get into some serious chemistry to begin to understand it. And I do know that the extra alcohol changes how the wine tastes.

A final technical factor that impacts the flavor of this wine is the fact that even though the wine went “dry” – as in the yeast ate all the available sugar and died off naturally when there was no sugar left to eat – there is still over 2 grams of residual sugars (RS) in the finished, dry wine. This could be a combination of tiny amounts of sugars the yeast couldn’t ferment like cellobiose, galactose, and pentoses, or it could just be left-over fructose or glucose. The point is that while 2.2 grams of RS won’t make the wine taste sweet, or even off-dry, it will be noticeable in the overall impression of the wine’s flavor… I think to its benefit because it balances the acid in the wine and adds a little “fat” to an otherwise lean wine.

So there you have it. Please let me know if you have any questions or comments!
Cheers,
Adam
 
*(Of course I had to put in a footnote.) If you drink a lot of natural wines, you may have a higher than average chance of encountering this phenomenon of unintentionally spritzy wines. If so, you can either drink it as is – some wines benefit from accidental MLF in bottle – or you could decant it for a couple hours to allow it to go “flat.” Or, using an ancient sommelier’s secret, you could pour the wine into a blender and turn it on for 30 seconds then pour it back into the bottle or a decanter – instant decant.