Dana Stemmler ~ Quality Winemaking at Bogle

In this episode, Jody Bogle is joined by Dana Stemmler, Winemaker at Bogle Family Wine Collection. Dana's journey to become an artisan winemaker was inspired by a life-changing trip to Italy, when she swapped a passion for art history with a love of wine.  In her 18th year at Bogle, Dana shares her commitment to crafting wines that reflect both nature's bounty and human ingenuity. 

To learn more about Bogle Family Wine Collection visit boglewinery.com.

Transcript

00:00 - Dana Stemler (Guest)
We're tasting in groups, like groups, usually varietals, or if we're tasting for a particular blend, like maybe 20 acres cab, we are tasting each individual, making tasting notes and trying to figure out what the message is and what we want to portray. And then you know, as all winemakers do, they start calling out wines that fit that characteristic, making trial blends, tasting them again, seeing how we could tweak it. 

00:35 - Jody Bogle (Host)
Welcome to the Bogle Story. I'm Jodi Bogle and I'm so happy to be sipping here with you today. Today, I'm joined by Dana Stemler, winemaker at Bogle Family Wine Collection. Hi Dana, hi Jodi, thanks for having me. Let's talk first of all about how you got interested in wine. Tell us your story. Yeah, so it was a really roundabout way. 

00:59 - Dana Stemler (Guest)
I first started my college years going to UC Santa Barbara thinking that I was going to pursue art and art history. I was undeclared and taking all sorts of classes and I really couldn't see a future and you know where that would take me so and I thought I was spending a lot of my parents' money away at college. 

01:21 - Jody Bogle (Host)
They probably thought so too. 

01:24 - Dana Stemler (Guest)
So I kind of took a step back and came home. I had, right before going away to college, I had gone on a trip to Italy with my Aunt Kathy. Our family were big wine drinkers, always sitting around the table drinking wine. They would let me participate, and so on that trip it was something that I was allowed to partake in pretty much every meal because, you know, in Italy that's just the way of life. 

01:48
So that was such a great memory for me and my aunt, and right around the time of me thinking what else could I do, I got wind that UC Davis had a winemaking degree called Viticulture and Enology. Davis was right up the road. It was a college that I had originally wanted to get into and had not gotten into, and so just kind of started putting the wheels together, figuring out what courses I needed to take to get into the program. And then the direction was set and once you got to Davis, did you immediately? 

02:19 - Jody Bogle (Host)
fall in love, you thought. And once you got to Davis, did you immediately fall in love? You thought, yes, this is it. 

02:25 - Dana Stemler (Guest)
Well, I absolutely loved it. It was a great combination between art and science. I had always loved science, was very successful in high school at it. I was also taking some science courses at UC Santa Barbara and I just felt like winemaking would be an awesome way to bring the art part kind of get rid of my creative itch. At the time I'd been drawing quite a bit, although I don't so much anymore. I feel being in the wine industry kind of scratches that creative itch for me. 

03:00 - Jody Bogle (Host)
Yeah, it was a great degree to combine the two, science and art. I've always said that winemaking is an art and science, so it's fantastic to hear that that's what came together for you as well. How did you end up at Bogle? And I have to say, 17 years now, it's 18 now. 

03:12 - Dana Stemler (Guest)
Oh it's 18, now 18 in April. Wow, Again comes back to my family. My mom was drinking Bogle Merlot. That was her red wine of choice. I feel like it always comes back to the Bogle Merlot, right? I think it was the number one selling wine at that time. So I graduated from Davis in the winter of 05. 

03:33
And about February of 06, my dad said you better hit the pavement and get that resume out there and my mom turned over a bottle of Bogle and said why don't you check out where Clarksburg, california is? And it really wasn't that far from the house, so it was like a 35-minute drive. I drove my resume up and I handed it in to Eric. 

03:54 - Jody Bogle (Host)
Right at the Home Ranch, right at the Home Ranch, when we were still making wine at Home Ranch. 

03:58 - Dana Stemler (Guest)
Yeah, I didn't even realize that there was a position open and he called me back and he said he was actually going to start looking for a position to just do winemaking data entry. That it was a little above my or a little below my degree but it would be a great start and I could do some of the lab analysis because at the time our our lab was quite small and low staffed I would say One for a staff of one One so I could help that gal out. And that's kind of where I started. I was doing data entry and lab analysis. 

04:33 - Jody Bogle (Host)
And so today your title is winemaker. What does your day-to-day look like today, dana oh gosh. 

04:38 - Dana Stemler (Guest)
So I come in check emails, check what was bottled the day before and see where we're at for meeting the schedule I'm putting together this time of year. I'm putting together blends because we're really trying to make a push to get as much into the bottle before harvest comes. We're emptying out a bunch of fermenters and we like taking advantage of harvest time so that we can shut down our bottling line and and utilize a lot of our bottling line staff out in the cellars, because the duties they change in longer days and so harvest time is a great time for bottling, to shut down and then harvest begins. So yeah, we're right on the cusp of that. 

05:19 - Jody Bogle (Host)
Let's talk a little bit about the winery itself. So we have heard from Ryan in another podcast about the winery and what makes ours special and unique. We talked about the tanks and the ramp and we talked about our barrel program, but I want to talk to you a little bit today about our single vineyard winemaking kind of process. Can you talk a little bit about what that means, and we'll go from there. 

05:47 - Dana Stemler (Guest)
Yeah, so we source fruit from anywhere between 90 and 130 growers or so, and many of those. 

05:56 - Jody Bogle (Host)
It's a lot. It is a lot. 

05:58 - Dana Stemler (Guest)
And we all have our estate fruit that comes in as well. So many of those growers have several blocks of several varietals and they're throughout the state in really nice growing regions. So just because we're, you know, starting to bring in, let's say, sauvignon Blanc, it doesn't mean that all of the Sauvignon Blanc throughout the state is ready at that time. So we will plan the pick based off of the bricks, the acid, making sure that the flavors are developed by block when the grapes are ready by block, when the grapes are ready by block, when the grapes are ready by block, and so when that comes through the winery to be processed, we venify it from grape all the way until blending, and that's quite a big commitment. 

06:41
So we're keeping every block as separate as possible. We're fermenting it in its own size tank and I'm sure Ryan probably mentioned all the different size tanks. I think we have like 20 or so different sizes, but within that you know several of that size and they're really designated for the different size blocks that we bring in. So it could be as little as you know, half a truckload, or it could be multiple truckloads and depending on the quantity, that's the size tank we pick. So we ferment the wine separate and it'll either age in stainless steel or go to barrel as its own individual lot and, like I said, and that's all the way through, blending. 

07:23 - Jody Bogle (Host)
So how do you guys decide when a lot comes in? So I know you're working with Chris Smith to determine when the grapes are ripe. We're going to talk with Chris Smith in another podcast as well about our vineyards and all our grower partners. How do you decide whether a Chardonnay, for example, gets fermented and aged in oak or if it goes straight into a stainless steel tank? Who makes that? 

07:47 - Dana Stemler (Guest)
decision Both Eric and I, we or if it goes straight into a stainless steel tank, who makes that decision? Both Eric and I. We talk about it so, fortunately, a lot of our growing partners. We've had for many years, so long-term growing partners. Because we're eventifying these blocks individually, we have a sense of history with each of the blocks. We know how they're going to perform generally and so if it's a lot that performs better in barrel, we'll put it that way and then vice versa in stainless. You know a lot of our Chardonnay hits barrel for our traditional line and our Phantom and Juggernaut, but we still, for our traditional line, like to do 50% of it in stainless. So there are lots that just perform better in stainless. You know just much more fruit forward and bright acidity that we don't want to really tame down with malactic fermentation in oak. 

08:36 - Jody Bogle (Host)
And because we're sourcing these same vineyards year over year, it's almost like you have a relationship with the lots. 

08:41 - Dana Stemler (Guest)
You know what to expect. Certainly do. I mean Phantom's a great example. You know, phantom, we're selecting the most premium Petits Rois and our most premium Zinfandel and oftentimes, year after year, they're the same growers that make it into that program, you know, and it would be easy to just blend those growers from the very beginning or earlier in the process so that we're not having to, you know, break down a lot as many times. But you know, we like to have the versatility and maybe that particular grower had an issue that year in the vineyard and maybe it wouldn't have made it in phantom. And a lot of times you don't see that until later on in the aging process. 

09:22 - Jody Bogle (Host)
So, at any given time, how many lots of wine are you and the team working with? Quite a few. 

09:30 - Dana Stemler (Guest)
So I mean just last year we did a little under 400 fermentations. 

09:35 - Jody Bogle (Host)
Wow, 400, 400 fermentations for 15 wines. 

09:41 - Dana Stemler (Guest)
Right, right, 15 plus or minus, that's incredible, yeah, with 35% of them being whites and the rest reds. The reds are a little more labor intensive because the pump overs Right, but yeah, it's a big commitment. It really is like a big commitment. 

09:57 - Jody Bogle (Host)
And do other wineries do this kind of thing? 

10:01 - Dana Stemler (Guest)
Other wineries of our size, Not to my knowledge. I mean, it is like I said, it's a big commitment. There's a lot of handling of each lot that you know our staff takes pride in doing, and I think that that is something that is easily dismissed as maybe inefficient or, you know, not necessary, but we believe in it. 

10:21 - Jody Bogle (Host)
So talk about quality then. Because we know this, we do this to be consistent and to maintain the quality in our range of wines. What does it allow you and the team to do by venting everything separately? 

10:37 - Dana Stemler (Guest)
so for a red wine, like, let's say, the season is like warmer and and I'm actually predicting this season, the 24, to be quite like this maybe a little more phenolics are going to be in the red profiles. Phenolics, so all of the tannins and mouthfeel, and color compounds. 

10:56
All the good stuff, all the good stuff, but you can definitely over extract that good stuff and make wine really hard and chewy, and so there will be blocks from history knowing that we could have the potential to overextract it. So we will start mitigating that right from the fermentation cut the pump over times shorter, maybe not have it on its skins and seeds so long, not have as hot of a fermentation. We're making decisions every day on individual lots For every single lot, for every single lot. 

11:28 - Jody Bogle (Host)
That is remarkable. That is just really, really remarkable. I have such respect for your team. For every single lot 400 or more. 

11:36 - Dana Stemler (Guest)
So that's just in the current season and then under roof. You know we have two full seasons and like part of the last, so we're still going through the 22, and we have all of 23 pretty much under roof, with the exception of some of the whites, and now we'll be bringing on the 24. 

11:53 - Jody Bogle (Host)
So how many wines do you taste a day? 

11:55 - Dana Stemler (Guest)
Oh, wow, on the average day, on the average, eric and I do taste the entire inventory on a six-week rotation. That's incredible. 

12:03 - Jody Bogle (Host)
So you know if there's 700 wines. 

12:06 - Dana Stemler (Guest)
it's quite good 700 wines in six weeks. 

12:08 - Jody Bogle (Host)
Yeah, wow, I just want to say that again. 700 wines in six weeks, that's incredible. There's no question in my mind that all of this contributes to the quality and the consistency in our wines. You guys have just recently gotten a ton of scores, gotten a ton of scores. We've gotten a lot of 90.91, 92 on the wines, both the traditional line and Juggernaut and Phantom. So congratulations, thank you. The scores continually kind of show your work right. Do you think we would be getting these kind of scores if we didn't make wine in this way? No, absolutely not. Are there any other benefits that single vineyard winemaking produces? 

12:50 - Dana Stemler (Guest)
Well, I mean I talked a little about the reds, but I think that you know, when there's ever any issue with a vineyard, we can take the season to really dissect that wine and see where we may be able to improve, whether it's a vineyard practice or a fermentation practice for the next season. So there's quite a bit of learning that goes on in just investigating why one wine will come out one way and another a completely different way, when we've treated them the same. 

13:23 - Jody Bogle (Host)
It's the science, it's the science, it is the science. 

13:25 - Dana Stemler (Guest)
And it's a really fun part of the science. 

13:28 - Jody Bogle (Host)
Investigatory. 

13:29 - Dana Stemler (Guest)
Investigating. 

13:30 - Jody Bogle (Host)
When something doesn't react the way you expect it to, and then trying to figure out why it's interesting. 

13:35 - Dana Stemler (Guest)
And also not to mention I mean cherry picking some of our best reserves for the tasting room. If we didn't have those lines separated, you know we wouldn't be able to find them in the mix. 

13:48 - Jody Bogle (Host)
Ryan talked quite a bit about the small lots as well, so we have. As winemaking has said, we have the most spoiled wine club out in the business. I feel like every time you guys produce a single vineyard or reserve wine that you've kind of culled out because you feel like it has phenomenal potential, do you see that when it first comes up the crush pad, can you? 

14:10 - Dana Stemler (Guest)
see it that early there are some signs, but really when I call them baby wines, when the wines are baby they're just really awkward and they have a long way to go to really develop, to see where they're going to end. Yeah, of course there are telltale signs like this has great potential, but it's really not until about a year out where, like this is definitely a nice wine I'd like to showcase. 

14:32 - Jody Bogle (Host)
So you talked a little bit about Phantom, how Phantom is kind of the reserve selection. Right, it's the best of our Petit Seurat and the best Zinfandel that you guys are picking out of those lots and combining. Talk about some of the other brands. And how do you decide from those 400 baby wines what goes into each of the? How do you? How do you determine what? 

14:54 - Dana Stemler (Guest)
goes where. Yeah, so on that six week rotation, we're tasting in groups like groups, usually varietals. Tasting in groups like groups, usually varietals. Or if we're tasting for a particular blend, like maybe 20 acres cab, we are, you know, tasting each individual, making tasting notes and trying to figure out what the message is and what we want to portray. And then, you know, as all winemakers do, they start calling out wines that fit that characteristic, making trial blends based off that, tasting them again, seeing how we could tweak it. 

15:26 - Jody Bogle (Host)
It's always fun to come by the lab. You and Eric are in there trying different things, trying blends. It's always fun, and you guys are always great, try this. What do you think? It's always so fun. I couldn't do it all day like you guys do. 

15:40 - Dana Stemler (Guest)
Well, there's still a lot of other work to do. That is the fun part of the job, though. What's your favorite wine to make? Sauvignon Blanc. It's very rewarding. It's quick to the market. Learning so much more about thiols and the precursors of thiols, so those are all of those flavor and aroma compounds that you identify with with Sauvignon. 

16:00 - Jody Bogle (Host)
Blanc. So like gooseberry and citrus, lemongrass and passion fruit and fresh cut grass. Those are all vials. 

16:07 - Dana Stemler (Guest)
I have not heard that word before, yeah, and so they're not always. They can be present, but they may not be in an aromatic form, and so just figuring out how to get that aromatic released from the precursors and so kind of playing around with that, different yeast, different temperature, yeah, sauvignon Blanc, it's real fun. 

16:31 - Jody Bogle (Host)
So we have a couple different Sauvignon Blancs. Is your favorite the Bogle traditional Sauvignon Blanc? 

16:36 - Dana Stemler (Guest)
It is because so much of my work goes into that, into that one. Yeah, I love our New Zealand as well. The Juggernaut Marlboro is delicious as well. 

16:45 - Jody Bogle (Host)
I want to ask a question that's not on the list, because I know that a lot of people are going to want to know the answer to this. Smoketain has become a huge concern in the industry. Can you talk a little bit about what it is and how we mitigate it at Bogle? 

17:01 - Dana Stemler (Guest)
Yeah, so smoketain. It's a set of markers, compounds that are found in the fermented must once the vineyard grapes have been in contact with smoke that's been in the atmosphere after a fire. You know there's still a lot to learn on how close that fire needs to be to a vineyard before it's actually picking up those compounds. But the tough thing is is just because the compounds are on the surface of the skin or maybe even have gone through the plant through respiration. If you were to just, you know, homulsify the grapes and test it for these markers, it would come back nothing. 

17:42 - Jody Bogle (Host)
You can't test it. It doesn't come through, it doesn't register. 

17:45 - Dana Stemler (Guest)
So they've found that these molecules are actually connected to the sugar. And you know, during fermentation the sugar is released to alcohol, so it's in that conversion where it starts to become present. 

17:56 - Jody Bogle (Host)
Yes, exactly. 

17:57 - Dana Stemler (Guest)
Okay, yes, so what we have done is we've, with your family's permission, we purchased a nice piece of equipment called a GC mass spectrophotometer and we have the method loaded up and validated on our equipment. And so what we would do is, if there was a vineyard that had the potential to having these smoke taint markers in the fruit composition, smoke taint markers in the fruit composition, we would go out and take a representative sample from the vineyard, do a quick like four-day fermentation in the lab in these little buckets, and then prep the sample and put it through our GCMS spec. But really what we're looking for is guaiacol and 4-methylguaiacol. 

18:37
Those are the two compounds that come across as ashy burnt. 

18:42 - Jody Bogle (Host)
Got it, and sometimes they occur naturally in certain grapes they do. Petit Verdot is one that comes to mind that I know always has a little bit of that smoky flavor. Syrah is another one. Syrah is another, I think, what it sounds like. You guys have a way, though, to test, within just a few days, which is fantastic. 

19:01 - Dana Stemler (Guest)
It really is, because then we can make the decision on whether or not we want to bring that vineyard in. You know, if it has low numbers and low potential to be in the wine, I don't think that we would shy away from bringing it in, because you know we make much larger blends and small amounts to add complexity to any wine. As you said, it's a naturally occurring compound in many varietals, but then we also have as I guess the contracts have now been written, we do have the ability to ask the growers not to pick it Right. 

19:30 - Jody Bogle (Host)
The beauty, though, of where we're located. Our estate acres are not at a high risk for smoke taint, just simply because of the location there isn't a lot of wooded kind of forested landscape that is susceptible to a lot of wildfires, so for that we're very grateful. What about fruit up in the foothills? So I remember a few years ago when there was a fire and we had some fruit up there. What we learned was that if the smoke is smoke has to be very, very close in proximity to the vineyard, or the fire does Not just the smoke, but the actual fire has to be in pretty close proximity to those vineyards for it to create those compounds. 

20:09 - Dana Stemler (Guest)
Correct, I believe. The further away the smoke travels, it starts to change in its you know, in its chemical makeup and not necessarily affect the grapes it oxidizes in some way. And so, yes, you are correct in stating that the fire needs to be fairly close and that the smoke actually needs to be around the grapes for several, you know, days or so. 

20:36 - Jody Bogle (Host)
Well, we're really lucky in where our growing areas are, first of all, our state fruits and you know, in a great location to avoid a lot of that. But it sounds like for those vineyards that may happen to be close to a wildfire, and we all know that. You know, now it's like we have fire season here in California, but it sounds like you guys are. You guys are on top of it and paying attention with our equipment. So thank, you. 

21:00
Okay. So I have one last question for you. I'm asking everybody this question. Are you ready? Okay, what's your regular weekend? Wine tunes and food Wine tunes and food. 

21:16 - Dana Stemler (Guest)
Oh wow, tunes. I'm going to have to come back to that. It would be whatever my husband's like. I don't really have a say over the radio. Okay, but wine. So recently, just this last weekend, I was drinking a ton of Albarino. It's been such a well hot summer, to say the least, but these lighter whites Sauvignon Blanc is a frisher, but the Albarino I've been drinking a lot of. 

21:46 - Jody Bogle (Host)
Albarino is getting very, very popular and we have one that is in our tasting room that you guys created. The grapes are from right in Clarksburg, correct, yeah, correct. It is a delicious wine. Oh, thank you. Okay, and what are you eating with your Albarino? 

22:02 - Dana Stemler (Guest)
Okay, you know I'm a salad girl. I like to make all sorts of salads at home. 

22:08 - Jody Bogle (Host)
That sounds like a perfect summer evening. Yeah, we'll have to get you on a cooking show next, dana, thank you for everything you do for Bogle. We're so happy to have you with the team sharing all this about single vineyard winemaking. We have no doubt this is why the wines have the quality and the consistency that they do, so thank you. 

22:29 - Dana Stemler (Guest)
Well, thank you. 

22:38 - Jody Bogle (Host)
Thank you for listening to the Bogle Story. We are happy to have you be a part of it.