Since when does Paso Robles get "May grey" and "June gloom"? Welcome to 2023.

If you live in California, you're not going to be surprised by this update. But it's been chilly so far this year. Sure, the winter made headlines, with record-breaking rains and cold temperatures. But even since then it hasn't exactly felt like sunny California. After a more-or-less normal April, we've gone back to a weather pattern in much of May and June that feels more like March -- or Mendocino -- than midsummer. Today we've had a heavy overcast as an unusual late-season low pressure system drifts over our area. This is not a sky that you expect to see in conjunction with this landscape:

It's not just the lack of sun. Since May 1st, temperatures here averaged nearly 7°F lower than normal, with only 12 days above seasonal highs and 22 below:

The cool patterns looks likely to persist through at least the middle of the month and perhaps longer, as it's caused by some longer-term conditions (static high pressure systems over the sub-arctic and low-pressure over the sub-tropics off the coast of California). For a more in-depth explanation, I recommend Daniel Swain's Weather West blog and Twitter feed:

New Weather West post out today: Unusual June pattern this week with some showers and thunderstorms possible in unusual places (though fire concerns are low); more cool weather could continue through much of June.#CAwx #CAwater #CAfre https://t.co/cKy6wsb9Ak

— Daniel Swain (@Weather_West) June 5, 2023

The last six weeks or so have been characterized by a deep marine layer and on-shore flow, which has meant that even our warmer days have usually started out foggy. That's not unusual in the early spring here, but it's typically not the case even by early May. And having deep gray clouds over lush green grapevines in early June is even more unusual:

The net result has been that the growing season, which got off to a slow start before catching up a bit in mid-May, has fallen further behind again. We're now something like a couple of weeks behind average, and more like three or four weeks behind most recent years. For a good comparison, check out the blog I published June 3rd, 2022 about fruit set, with pea-size berries in Grenache. By contrast, Grenache is still in mid-flowering today:

Our biggest worry right now is that cool, breezy weather isn't ideal for berry fertilization, and raises the risk of shatter. But no one I talk to is particularly concerned. It hasn't been all that windy (the last month has had only one day with a top wind gust over 20mph), we've had warmer days interspersed between the chilly ones, and it hasn't rained. Even if we do get a passing shower tonight or tomorrow, it doesn't look like it will be much, or that it will stick around for long. Plus, everyone is seeing what we are: unusual vigor in the vineyards thanks to all our winter rain, with large clusters and plenty of leaf area. If we lose a small percentage of that crop, we can afford that better than we would have been able to the last few years.

Finally, there's plenty of runway left in the growing season. We've gotten used to starting to pick in August and finishing by mid-October. But in the 2000s it was more normal that we'd start in mid-September and finish in early November. In Paso Robles that's not a huge risk, since the rainy season doesn't usually start in earnest until around Thanksgiving. That's a big part of why we chose this location. So if we need to wait, we wait. There are even benefits to doing so, as the grapes will spend longer on the vines and we're more likely to be picking in cooler weather.

Meanwhile, we'll enjoy the unusual backdrop to our vineyard activities. "May grey" and "June gloom" aren't normal features of Paso Robles weather. But it seems like in 2023 we're getting a taste of both.

The Adelaida District's Limestone Layers Laid Bare

On Friday, Winemaker Neil Collins poked his head into the office we share, looking excited, and said, "Hey, you got a minute?" I did, and we hopped into the ATV and Neil piloted us south across the creek and along the south side of the reservoir the property's previous owner made back in the 1950s. He stopped near the dam, and we headed out on foot. What he had found was remarkable: that Las Tablas Creek had become an exhibit for the local geology.

This has been a banner year for Las Tablas Creek. After three years where it barely ran, the series of storms that we got in late December and early January got it flowing fast:

During a break in the storm Viticulturist Jordan Lonborg got down to shoot this video of Las Tablas Creek… and it’s moving fast, has filled up our reservoir and is now flowing through the spillway for the first time since early 2019! pic.twitter.com/mTWzT1o9hJ

— Tablas Creek (@TablasCreek) January 5, 2023

A week later, after another storm had dumped six more inches of rain in about 24 hours, it burst its banks and flowed over Adelaida Road just outside the winery, producing impressive enough footage that it made it onto several national networks as an illustration of the widespread California flooding:

All that water flowing down the creek and into (and out of) the reservoir changed the landscape in in visible ways. In the creekbed it's clear how high the water came because everywhere below that line it scoured away the topsoil and exposed the limestone layers underneath:

At the far end of the lake is a spillway through which the water flows once it has filled the reservoir. It's a remarkable illustration of the local geology. Most of the calcareous soils that underly the Adelaida District are soft, as much clay as rock, which has given rise to the (incorrect) theory that none of it is limestone¹. While it's a good thing that we don't have solid limestone underneath us, as limestone is too hard for vines' roots to break up or break through, there are bands of limestone that run throughout the region. The previous owner made use of one of these layers in the creation of the spillway, which follows the slanting descent of the layer from dam-level down to the original creekbed. Here are two views: on the left from above the spillway in late January, and on the right from below last week:

In both photos, though most clearly from below, you can see the many layers of softer rock that the water has eaten away over the years, while staying above the harder limestone layer. 

A side-stream that flowed into the creek showed another good example of the mix of harder and softer calcareous layers, and the step-like pattern that is repeated in creekbeds throughout the region:

While the softer layers crumble and decompose, the harder limestone bits stay in the topsoil. Most wineries remove them before planting anything, as otherwise they chew up tractors at an alarming rate. The rocks that are removed are the raw materials for the walls you see at Tablas Creek and around the Adelaida District:

All this rock is sitting there year-round, just a few feet below the surface. Thanks to the rain we've received (and continue to receive) this winter it's easier to see than ever. 

Footnote:

1. If you're interested into a deep-dive into the chemistry and geology of the calcareous soils out here, check out my 2020 blog Why Calcareous Soils Matter for Vineyards and Wine Grapes.

After two of our five rainiest months ever, we're ready for a break... but grateful for the moisture

I left California three weeks ago, just after Christmas, to spend some time in New England with family. At the time, I was feeling cautiously optimistic about how our winter was shaping up. We'd banked nearly 13" of rain and were at something like 170% of the rain we'd have expected at that point in the winter. The day I left, it started raining and essentially hasn't stopped. With the two-thirds of an inch that we got today, this makes 20 of the last 21 days we've seen measurable precipitation. The end-of-December rain pushed us to 13.28" for the month, making it our second-wettest December in the 25 years since we installed our weather station and a top-5 rainfall month overall.

Then came January. A series of atmospheric river storms paraded across the Pacific and slammed into California. Some were aimed farther north, but still dropped a couple of inches of rain. And one arrived on early in the morning of Monday, January 9th with its plume of moisture directed squarely at the Central Coast. We tallied 5.65" that day, including more than 4" in its peak between 1am and 10am. And when we arrived to see how things looked at the winery that morning, we realized that we couldn't even get there because Las Tablas Creek was flowing over Adelaida Road:

We are getting pummeled by this storm in Paso Robles wine country. This is Vineyard Drive near the entrance to our vineyard. All along Vineyard and Adelaida there are trees and branches down, water spilling over, and mudslides like in the last scene on Adelaida Rd. pic.twitter.com/QVydqd3qfU

— Tablas Creek (@TablasCreek) January 9, 2023

It wasn't until Wednesday that we could make it into our facility, and Thursday that we could reopen our tasting room. Thanks to some great work by our neighbors at Halter Ranch the debris blocking the culvert that was causing the creek to flow over the road was removed before the road was critically damaged. There was a section of Adelaida Road a few miles east of us that wasn't so lucky. And we had to close again this past Saturday because a new storm made access to the winery unsafe. Residents and businesses out here are still picking up the pieces, and what we're seeing is minor compared to the scale of damage around the state, with 19 deaths so far and floods forcing people from their homes from Sacramento to Santa Barbara.

Still, while we wish it had been spread out more, we're grateful to have received the rain. And when I got out in the vineyard today, it was stunning: lush and green from the saturated soils yet with minimal signs of erosion even on our steepest slopes:

There wasn't really any standing water, even at the bottom of the hills, thanks to the remarkable ability our calcareous soils have to transport enormous quantities of water from the surface to deeper layers. That said, there was some water slowly trickling downhill in blocks like this head-trained Mourvedre at the northern edge of the property. It was wet enough that I nearly lost my boots getting this shot:

For all its beauty now, it's clear that things were pretty wild a week ago. You can see the deep cuts in the channels where valleys became rushing creeks (left) and the impact of 36 hours of water flowing over Adelaida Road (right):

With nearly half the month still to come, January 2023 is already our third-wettest month in our history, trailing only January 2017 and (from before I started writing this blog) February 1998. We're at 281% of expected rainfall for this point in the winter and above our full-winter long-term average. After three years of drought, that's a huge relief.

You can see from the rainfall distribution above why this season is so critical for us. We get three-quarters of our annual rainfall between December and March. If we have an extended winter dry stretch, it's almost impossible to make it up later. And drought impacts are cumulative. Grapevines generally do fine the first year of a drought cycle, thanks to their accumulated vigor. But starting the second year, you see the reduction in yields, and by the third year you start to see impacts on vine health and mortality. That's played out for us the last three years. 2020 saw roughly average yields. But 2021 saw yields off by 26% and 2022 saw them decline another 8%. A quick look at our available wines shows many more sold-out than for sale. And that's before we've even gotten to the 2022 vintage, from which there will be several wines we just won't be able to make. So getting rain this winter was particularly important.

Vineyards themselves are typically resilient in the face of extreme rainfall events. Those events typically come in winter, when the vines are dormant, and grapevines' deep roots play an important role in helping hold soil in place. Vineyards that are regeneratively farmed tend to do even better. Both no-till farming and planted cover crops (one or the other is required for regenerative certifications) keep surface erosion to a minimum. The focus on building up the organic matter in your soils helps them hold more moisture. And the biodiversity in regenerative farming systems tends to create a denser web of life than monocultures. Witness this section in the middle of the vineyard, which a decade ago was one of our most erosion-prone areas but which we planted to a mix of perennial crops that would act as attractors for beneficial insects. The combination of shrubs and deep grass, already well-established because it hasn't been tilled in years, made for one of the least-soggy sections of the vineyard:

Looking forward, we're supposed to get a few more showery days and then a solid week at least of sun. That will be welcome for everyone, from vineyard to residents to businesses. It should give the county a chance to get out and repair the damaged roads. It should shift the cover crop into overdrive, and make for some very happy sheep. It will give the soils a chance to transfer the water to deeper layers and free up space at the surface for the next storm. It might even give us a chance to get started on our pruning, which we've been unable to do because pruning in wet weather encourages the spread of fungal diseases. But as happy as we are with what we've received, we're hoping this isn't the end of the rain. The local reservoirs still have significant room; while Lake Nacimiento is at 87% capacity, Lake San Antonio is only at 32%. At Tablas Creek we're chipping away at an accumulated rainfall deficit of 28" from the last three years of drought. Plus there would be benefits during the growing season, as soils with high moisture content stay cool longer in the spring and delay budbreak, which would reduce our risk of frost damage. And on a purely aesthetic level, there's a particular character to the green here after winter rain that I love. Who wouldn't want more of this?

If you were negatively impacted by these storms, please know you have our deepest sympathy. It's been a rough couple of weeks for California. But if you were worried that the vineyards here would be suffering, hopefully we can at least put that to rest. We have high hopes for the 2023 vintage.  

A Vineyard Life: When It Rains in the Adelaide

By Austin Collins

There is no doubt that winter is upon us. This past week alone we have received over five inches of rain. That's more than our long-term average for the month, and half of what we got in one of our wettest-ever Decembers last year. And there is more on the way. We even got a brief, but incredibly strong hail storm, littering the ground with marble-sized pellets. In fact, it was my one-year-old's first time seeing hail. One of many firsts under the skies of Tablas Creek Vineyard, just like his father. It is days and weeks like this that allow us to loosen our shoulders and enjoy our holidays just a little bit more. These past few years of drought have taken a severe toll on us, and are a big reason why, along with the unseasonably late frosts of 2022, our crop yields have been unprecedentedly low. So, the next time you are having dinner and rain is tapping on your window, open a good bottle of wine and give a nod to the clouds.

With the recent rainfall we received I was taken back to my early years on the Tablas Creek property. This is the view off of my back patio. Down the steps and into the bed of Las Tablas Creek, the access point to many of my childhood adventures. During the rainy season this creek would begin to flow again, and with the return of water came life. I have strong memories of hearing the creek rushing through the darkness of the Adelaide nights, the sound of toads reverberating off of the ancient oaks. Back then there wasn't much traffic on the roads and the sounds of the land were accompanied by only silence.

As I child my favorite thing to do was explore this property. Sure, I played some sports, but I remember being at my happiest romping through this wild and dirty playground. The great thing about having the vineyard and forest as your playground is the changes it experiences throughout the year. In summer it's warm, dry, and full of sun-drenched grasses until late in the evening. In the winter my playground would transform. The cold would encourage leaves to cover the forest floors, the vines became bare, hardly resembling their summertime guise. Small cover crops sprouted and annual grasses began to peek through the darkened soil.

When it rains at Tablas Creek, vineyard work comes to a standstill. Tractors are parked under cover and sheep rest on blankets of straw in the barn. That meant I had the hills to myself, a child of the mud.

Good, wet storms do not hit us too often here in Paso Robles. That being said I feel as though people can still take them for granted when they do come. In fact, it confused me as a young child when people deemed the weather miserable when water fell from the sky. "Bring it on", I always thought. I think our dry farmed vines and olive trees agreed with me.

The rain sure meant a lot to me back then. It still does. How can it not? Look how much it does for us. If you don't grow crops for food or for wine, I think everyone can appreciate the beauty rain brings to the planet. Whether it is during a storm, or after, through the clearest air our lens can find, rain did that.

[Editor's note: after this piece was published, our Winemaker Neil Collins, Austin's dad, sent us this photo of Austin playing in one of these very same puddles. As he said, "proof".]

Paso Robles is (Still) Insanely Beautiful, Fall Edition

Three weeks ago, with the first clouds in the sky and the vineyard starting to change into its autumn colors, I caught some of this new beauty and shared it in a blog. Since then, we've gotten three inches of rain, without a frost. The result has been a new color palette, with green grass growing while the autumn colors deepen to auburn. Because we usually get a hard freeze before we get significant rain, it's rare and beautiful to have this green and golden brown combination:

But that's not the only change. The moisture has meant that we've had a series of lovely foggy mornings out here, water dripping off the vines and settling on the new grass, sunlight softly diffused:

I keep coming back to the spot from which I took the final photo in my last session, at the center of the vineyard looking west over a section of head-trained Mourvedre, one of my favorite rock walls, a new area of Biodynamic plantings, and a big oak tree. I particularly love the lines of hills receding toward the horizon:

The colors of the vines vary, but Counoise is always some of the most colorful. I love the contrast with the big old live oak that grows in the middle of this block:

One of the things we've done since we finished harvesting our grapes was complete our one-day olive harvest. I didn't get any photos of that, but the grey-green of the olive leaves makes a great contrast to the brighter colors of the vineyard (in this case, Tannat on the right):

I'll leave you with one more sunset photo, the late-afternoon light illuminating Syrah's fall colors. 

How long we'll have with this landscape is an open question. We have more rain forecast for next Tuesday, which will be great. There's a chance of a frost the night before, which would put an end to much of this color, but if we dodge it there's not another one on in the forecast. Could we keep these colors all the way to Thanksgiving? I don't know. But I'm going to enjoy them while they're here. If you're visiting Paso Robles in the next few weeks, you're in for a treat.    

Paso Robles is Insanely Beautiful Right Now, Fall Edition

The seasons are definitely changing, and earlier this year than our last few. It's been cool and breezy during the day. Nights have already dropped near freezing several times. The grapevines have been coloring up like they think they're in New England. And (wonder of wonders) we have clouds:

Combine the clouds, the vineyard colors, the lower sun angles, and a touch of humidity in the air, and you have a landscape which is dramatic and beautiful. Witness this view, looking west over our oldest Grenache vines into the setting sun:

Most people think of wine country in summer, when you've got a high-contrast color palette. Bright blue sky. Dark green oaks. Golden hillsides. Winter and spring are their own kind of beautiful, softer and more yellow-green as the season's rainfall covers hillsides with green grasses and wildflowers. I've shared how much I love getting out into the vineyard to photograph those seasons. Fall can be over in just a few weeks, if you aren't paying attention. All you need is one frost, which usually comes in November sometime, and the colors fade to brown almost overnight. But for those few weeks it's glorious:

It's not just the vineyard. The low sun angles enrich the colors of the grasses, as you can see from this shot of a picnic table we've put at the top of our tallest hill:

Panning back a little more allows the oak trees (beautiful in any season) to be contrasted against the sky, layered gold and robin's egg blue from the clouds and the setting sun:

One last photo, my favorite of the session, and one of my favorites I've ever taken out at the vineyard. You're more or less in the center of the vineyard, looking west past many of our Biodynamic plantings of flowering herbs and fruit trees, vines to the left turning color while the lines of hills march toward the horizon:

We may only have another week or so of this landscape. Our first winter storm is forecast for this coming weekend, and if we get any significant wind with the rain, the leaves will likely come off the vines. The rain will begin the vineyard's next transformation from gold back to green. And we'll all celebrate the end of fire season. But if you have the good fortune to be here over the next week, you're in for a treat. If not, hopefully I've captured some of it for you to enjoy from home. 

Paso Robles is Insanely Beautiful Right Now

I took a walk yesterday across Las Tablas Creek and up the section of our property that we're calling Jewel Ridge, named after a great old vineyard dog who we buried there. This is the parcel that we bought a decade ago, knowing that we wouldn't need it for five years at least, because land this good, contiguous with our property, doesn't come on the market according to your schedule. So, we bought it, and have spent the last decade building up the soils, using it as a convenient staging zone for our flock when they can't be in the vineyard, and slowly mapping out the new blocks. A quick panoramic from the top, looking west, will give you an overview:

You can see how green things are getting after the foot of rain we received in late January. This view, looking under one of the walnut trees that we kept (the whole property was a dry-farmed walnut orchard when we bought it) shows it even more clearly. The stakes you see are for us to plant later this winter.

The ridgetop has spectacular views on three sides, and also looks to us like some of the best vineyard land in the area. We've already planted some Mourvedre and Grenache. The whole property will be head-trained and dry-farmed, following the model that we've loved so much on our Scruffy Hill parcel.

Almost the entire property is steep, with slopes as much as 30%. That's a bit of a challenge for farming, but nothing we haven't figured out already. This view of the east-facing slope of Jewel Ridge is representative. 

The highlight of the property is a west-facing natural amphitheater. I took the panoramic photo I shared first looking straight west over that bowl, but because of the panoramic distortion it's hard to see the land's curves. This shot of Sadie halfway down the slope maybe shows it more clearly:

Another perspective, looking south across the top of the bowl, gives you a different slice. You can see some of the vines we planted last year, tied to the stakes in the middle ground. We hope to get our first small crop off this parcel in 2023.

As I was walking back, I caught this photo of the moon rising over the west slope of Jewel Ridge. The colors at this time of year (deep blue sky, occasional puffy white clouds, cream-colored rocks, dark brown vines, and bright yellow-green cover crop) is my favorite. 

One of the appeals of the property to us was the lake that the previous owner's father created in the 1950s by damming up Las Tablas Creek. In the long term, we're exploring how we might use this water to frost protect more of the property. In the short term, it's a lovely spot, with ducks swimming on the surface: 

Finally, maybe my favorite shot of the day, looking up from the creekbed toward our established vineyard, Sadie posing pastorally:

We're excited that we've been able to start welcoming guests back to our tasting patio in the last month. If you're planning a trip to Paso Robles in the coming weeks, you're in for a treat.

A picture is worth 1000 words, late fall edition

With our tasting room closed again due to our Regional Stay Home Order, we've decided that it's more important than ever to share lots of photos to make sure that people can maintain a sense of what it's like out here. To that end, I was out yesterday walking around the vineyard to get some photos to share, and found it inescapable how dry it was. Often, by early December, we've gotten a couple of nice rainstorms, and the vineyard is already notably green. Not in 2020. It's been cold, which is good, because it forces the grapevines into dormancy, but we've only gotten a couple of small rainstorms, and nothing recently. I couldn't help but feel the stress of the grapevines I passed.

And yet, the annual cycle continues. I got one photo of a head-trained Mourvedre vine, roughly a decade old, that I thought was illustrative:

Consider, if you will, the stresses that this and all our other vines have endured this year and endure, more or less, each year:

• An almost total lack of topsoil. Our deepest topsoils are a couple of feet thick, and much of the property has the fractured calcareous shale you see right at the surface. 
• Minimal rain for six months every summer and fall. Our total rainfall in the last 8 months is 0.8"⁠. That's a little extreme, but the average total May-October rainfall here at Tablas Creek over the last 25 years is just over two inches. Yes, our winters are wet. And yes, our soils do an amazing job retaining that winter rain. But this is a lot more extreme than anything grapevines have to deal with even in the driest parts of Europe.
• Regular frosts in the winter. In the last month, it's dropped below freezing ten nights. That's not unusual; we average about 40 frost nights a year here, and though we've been lucky in recent years, spring freezes are the most significant annual weather threat we face. That too is more than Mediterranean regions like Chateauneuf-du-Pape face.
• Scorching summers. This summer, we had 21 days top 100. That was unusual; I wrote earlier this year how 2020 was the year where climate change felt real. But we average roughly a dozen 100+ days each year. And while the Mediterranean can get very hot, 90s are a lot more common than 100s there.

That Mourvedre vine has never had a drop of irrigation. There's not even any irrigation infrastructure in that block. And yet, each year it sprouts, flowers, ripens a crop, and stores what it needs for the next year. And out of this struggle comes grapes (and wines) of intensity and character. Deep roots that reflect the calcareous soils we love. Resilience and longevity.

It's not an easy life, but we wouldn't have it any other way.

Why Calcareous Soils Matter for Vineyards and Wine Grapes

What do regions like Champagne, Burgundy, Chablis, Tuscany, Alsace, the Loire, Saint-Emilion in Bordeaux, and Chateauneuf-du-Pape all have in common? They've all got soils that are variously described as chalky, decomposed limestone, and calcareous. In chemical terms, all are high in calcium carbonate, the basic building block of marine life.

So too does much of the Paso Robles AVA, particularly the sub-AVAs of the Adelaida District, Willow Creek District, Templeton Gap, El Pomar, and Santa Margarita Ranch. In all these regions, if you find a road cut, the rocks will be chalky and white, and if you dig into them you'll find marine fossils, from fish scales to oyster shells to whale bones. Yes, ten million years ago, our part of Paso Robles was under the Pacific Ocean. This makes our land, in geologic terms, relatively young. When they make their way to the surface, the rocks are creamy white and surprisingly lightweight:

What Are Calcareous Soils?
Calcareous soils are formed from the crushed up and decayed shells and bones of sea creatures. These layers settle down to the bottom of shallow oceans and, depending on how much heat and pressure they're subjected to, can be as soft as talc or chalk, or as hard as limestone or even marble. Of course, in order for plants to be able to access the calcium carbonate, it needs to be friable: soft enough for roots to penetrate. This means that even when you hear about a region having "limestone soils" the value to the plants isn't in the limestone itself, but in areas where the limestone has decayed into smaller particles.

From a grapevine's perspective, it doesn't really matter if the calcareous soils come from the erosion of limestone (as in Burgundy) or whether they never quite got heated and compressed enough to become rock (as in Paso Robles). The net impact is the same. There are four principal reasons why these soils are so often good for wine quality.

In winter, the calcareous clay absorbs moisture, turning dark.  Note the roots that have pene- trated between the layers of clay.

Benefit 1: Water Retention & Drainage
Calcium-rich clay soils like those that we have here have water-retention properties that are ideal for growing grapevines. Some water is essential for cation exchange -- the process by which plants take up nutrients through their roots. But grapevines do poorly in waterlogged soils, which increase the likelihood of root disease. Calcium-rich clay soils have a chemical structure composed of sheets of molecules held together in layers by ionic attractions. This structure permits the soil to retain moisture in periods of dry weather but allows for good drainage during heavy rains.

The porosity of our soils mean that they act like a sponge, absorbing the rainfall that comes in the winter and spring months and holding it for the vines to access during the growing season. We've done backhoe cuts in late summer, after it hasn't rained for several months, and while the top few feet of soil are dry, there's moisture in the layers six feet down and more.

At the same time, we never see water pooling around the vines. Part of that is that our whole property is hilly. But hillside vineyards in other regions still end up with standing water at the bottoms of the hills. We never do. That balance of water retention and drainage is ideal, and it allows us to dry-farm in the summer months of what is essentially a desert climate. 

Benefit 2: Higher Acids at Harvest
We've had anecdotal evidence of calcium-rich soils producing wines with more freshness for years. At the symposium on Roussanne that we conducted last decade, producers from non-calcareous regions (from Napa to the Sierra Foothills to vineyards in eastern Paso Robles with alluvial soils) consistently reported harvesting Roussanne roughly half a pH point higher than those of us from calcareous regions like west Paso Robles and the Santa Ynez Valley. But the chemistry of why this was the case has only become clear in recent years. 

It appears that the key nutrient here is potassium, which is central to the processes by which grapevines lower acidity in berries as fruit ripens. High calcium levels displace potassium in the soils, inhibiting this chemical process and leaving more acidity at any given sugar level. Of course, this can be a challenge. I have friends in other parts of Paso Robles whose pH readings are so low at the sugar levels that we like to pick at (say, 22-24° Brix) that they have no choice but to wait for higher sugars. This can produce wines that carry massive levels of alcohol. But in moderation, it's a wonderful thing. I'm grateful that (unlike in many California regions) we can let malolactic fermentation proceed naturally, producing a creamy mouthfeel without unpleasantly high alcohol levels. In much of California, the higher harvest pH readings mean that they have no choice but to stop the malolactic bacteria from working to preserve the sharper malic acids in the finished wines, for balance. 

The calcium-rich layers of the mountain behind the winery shine bright white in mid-summer

Benefit 3: Root System and Vine Development
Unlike cereals and other annual crops that have shallow root systems, grape vines have deep root systems. This means that the composition of the deeper soil layers is more important for vine health and wine character than that of the topsoil. It also means that amending the soil (by, for example, liming to add calcium) is less effective than is natural replenishment of essential nutrients from deeper layers. 

Grapevine roots are remarkable. They can penetrate dozens of feet into soil in their search for water and nutrients, and they continue to grow throughout the vines' lives. This means that the physical properties of the soil are important: a hardpan layer through which roots cannot penetrate can have a serious negative impact on a vine's output. Calcareous clay's tendency toward flocculation (soil particle aggregation) creates spaces in which water can be stored. In addition, the softness of these soils means that as they dry out, they shrink, creating fissures through which roots penetrate to where more residual moisture can be found. As they get wet, they expand again, opening up yet more terrain for the vines' roots to access. This process repeats itself annually. In our vineyard we've routinely found grapevine roots ten feet deep and deeper in experimental excavations.

Benefit 4: Disease Resistance
Finally, there is evidence that calcium is essential for the formation of disease-resistant berries. Calcium is found in berries in its greatest concentration in the skins, and essential for the creation of strong cell walls and maintaining skin cohesion. However, if calcium is scarce, plants prioritize intracellular calcium over berry skin calcium and berries are more susceptible to enzyme attack and fungal diseases.

Where Are California's Calcareous Soils?
When my dad and the Perrin brothers were looking for a place to found the winery that would become Tablas Creek, calcareous soils were one of three main criteria they were looking to satisfy (the others were sun/heat/cooling and rainfall). But they quickly realized that soils like these are rare in California, except in a crescent of land in the Central Coast between the Santa Cruz Mountains to the north and Lompoc to the south. The portion of this this area that is on the western slope of the coastal mountain ranges is too cold to ripen most Rhone varieties. The western and southern pieces of the Paso Robles AVA, on the eastern slopes of the Santa Lucia Mountains, are home to the state's largest exposed calcareous layers, and it's largely because of this that in 1989 we bought property here.

There's a great story about how they went about finding soils. As they tell it, they decided that it was a lot cheaper and faster to look at road cuts than to hire backhoes and dig their own. They looked for the better part of four years around California without finding soils that excited them. Until they were driving along Peachy Canyon Road one afternoon in 1989, saw one of the many switchbacks where CalTrans had dug into the hillside to make the roadbed, and pulled over to see if the white rocks that they noticed were really what they'd been searching for. The composition looked right, the fossils looked right, and they then brought over a French geologist to confirm their impressions. They put in an offer on the property where we are now later that year.

We've thought since the beginning that finding calcareous soils would be a key to making great wines. Learning the science behind why only underscores the importance that the vineyard's founders put on this search.

Further Reading:
Thanks to Dr. Thomas J. Rice, Professor Emeritus of Soil Science at Cal Poly, for pointing me in the right direction on some of the trickier geology questions. See also:

• "Calcium in Viticulture: Unraveling the Mystique of French Terroir, Part I and Part II" by Valerie Sexton, Wine Business Monthly. Originally published September/October 2002.
• "Effects of juice pH and potassium on juice and wine quality, and regulation of potassium in grapevines through rootstocks (Vitis): a short review," by S. Kodur, Department of Agricultural Sciences, La Trobe University, Bundoora, Victoria, Australia, 2011.
• "Effect of rootstock on must and wine composition and the sensory properties of Cabernet Sauvignon grown at Langhorne Creek, South Australia," by R. Gawel, A. Ewart and R. Cirami. Wine & Viticulture Journal, January 2000.

Congratulations to Winemaker Neil Collins, Paso Robles Wine Industry Person of the Year for 2019!

At the end of January, nearly 30 of the Tablas Creek team joined some 200 members of the Paso Robles wine community to celebrate our long-time winemaker Neil Collins, who was voted by his peers the 2019 Paso Robles Wine Country Person of the Year. You can read the official announcement from the Paso Robles Wine Country Alliance. 

With one exception -- the 1997 vintage, during which Neil was working at Beaucastel -- Neil has had a hand in every vintage of Tablas Creek. We first met him in 1994, when he was Assistant Winemaker at Adelaida Cellars, where we rented space to make our first few vintages of practice wine. By the time we'd gotten our French clones into production and built our winery in 1997, we'd become so impressed with Neil's work that we offered him our winemaking position and the opportunity to spend a year working at Beaucastel. We're honored that he's been here ever since. 

Along the way, Neil created two other businesses here in the Paso Robles area, and this award recognized these contributions at least as much as his winemaking at Tablas Creek. He started the Lone Madrone label with his wife Marci and his sister Jackie in 1996, through which he has championed dry-farmed vineyards on Paso's West side while focusing on heritage grapes like Zinfandel and Chenin Blanc, along with (of course) Rhones and the occasional parcel that was too good to turn down. Nebbiolo, anyone? And as if that wasn't enough on his plate, for the last decade he's been leading a Central Coast cider renaissance through his Bristol's Cider label and the Bristol's Cider House in Atascadero.

When my dad and Jean-Pierre and Francois Perrin started Tablas Creek, they felt pretty confident in their abilities to grow, make wine out of, and sell Rhone grape varieties. (As it turned out, that assumption was probably a little optimistic, but what great adventure ever gets started without a little unwarranted optimism... and anyway, that's a story for another day.) What they found in Neil, in addition to a man with relentless curiosity and legitimate hands-on winemaking chops, was someone who was steeped in Paso Robles. Although he's not a native, he spent his whole winemaking career here, from its early days with Ken Volk at Wild Horse through his extended stint with John Munch at Adelaida. I know that it meant a lot for him to have Ken, who gave him his first job in wine, be the one who presented his award at the Gala. I videoed the presentation speech:

You might well ask how he's able to run what is in essence three separate businesses while still holding down a full-time job here at Tablas Creek. That's part of what makes Neil special. He has a great ability to get things rolling, empower the people who work for him, and then keep tabs on the status of the many projects he's working on without having to (or, just as importantly, feeling like he has to) do everything himself. But it's not that he's content with the status quo. Far from it. His relentless experimentation is one of the things that has allowed Tablas Creek to grow and thrive the way it has under his watch. And it's one of the reasons why his lieutenants here at Tablas Creek tend to stay for the long term. I asked Senior Assistant Winemaker Chelsea Franchi, who's been here more than a decade herself, to share her thoughts on Neil, and I loved what she told me: "One of the things I love most about working with Neil is watching him build community and having the chance to be part of it. You see it in his close-knit family for sure, but it extends well beyond that. His groups of friends and colleagues, the family he's built in the Tablas Creek cellar team, his employees from Lone Madrone and Bristols - it's a true delight to be near someone who cares deeply about the humans around him."

I think you'll get a good sense of why people want to work with and for Neil from his acceptance speech:

It's an honor to call Neil a colleague and a friend, and I couldn't be more excited that he received this recognition.