Week 22 (18 - 22nd)

This is my last week at the HRC. It is hard for me to believe that six months have passed, the growing season has come and gone, and now I am walking away from this experience. Everyday at the HRC has taught me a lesson, an irreplaceable skill and unique education. I am extremely thankful that I was able to learn from such passionate educators and will be forever indebted to them.

Nick taught me a titration alternative in order to measure sulfur in wine samples: Aeration Oxidation. This allows you to  measure both free and bound sulfur, which can be added together in order to determine total sulfur. Though this method takes a little more hardware, it's more precise and the method utilized by most wine makers. 

After loading and unloading 400 bails of straw, we are finally covering the pinned j-vines for the winter. The only problem with this method is that straw makes an enticing home for mice. In order to combat this we place two mouse poison blocks next to each vine. We then fluffed roughly a bail of straw per vine, covering all sections and capping the top with chunks of straw. 

We finished the back-breaking work in two days, covering all the j-vines with a blanket for the winter. An alternative method to straw would be to cover the vines with dirt, however, this can be messier and more difficult to uncover in the spring. Bring on the snow!

Two analytical ways to assess the season: our spray program and precipitation. We only sprayed three times (and then two organic potassium sprays to control powdery mildew on our European varieties) throughout the season, where some wineries spray once a week. Spray programs are meant to by dynamic, targeting specific needs at specific times. This some growers find hard to grasp, which is unfortunate for the environment and the consumer (and a waste of money). Due to these practices mutant resistant pathogens are more likely to arise as well. 

Week 21 (Nov. 11 - 15th)

Three coolers of grape samples from vineyards around the state arrived this week. All the grapes were frozen, so we first had to let them defrost. I next crushed the samples by hand and pressed them out with the little press on the right. We collected two tubes of each sample.

I recorded the brix, TA and pH for each sample. This kept me busy for the greater part of a day.

The wine cellar is filling up! I am clinitesting, racking, and adding sulfites to roughly five or six batches per day.

The end of the week finally warmed up enough for us to start and finish pinning down all the j-vines. We also were able to dig up the nursery, a task which we had been delaying for the past few weeks in order to allow the ground to dry out and warm up. This project was important to get done before a hard frost, as all of last year's crosses (some being cold-vulnuerable) were planted in the nursery for this growing season. We used an under-cutter, which was attached to the back of a tractor, to pry the vines up. We would then collect marked vines (healthy vines with little disease) and organize them in bundles. We discarded the majority of the nursery, maybe 70%, as these underperformed and/or had genetics that were susceptible to diseases. We moved all the bundles to a cellar, where they were burried in peat in order to remain dormant until spring. 

Week 20 (Nov. 4 - 8th)

Since our winery is for research purposes, we need to remove as many variables as possible in order to objectively assess the benchmark quality of the wine that a various vine produces. One of these variables which we control is the residual sugar of the wine. We ferment all of our batches to completion, meaning we wait until they are completely dry. In order to determine this, we utilize the "Clinitest" method. We drop a tablet into 0.5mL of wine and then observe the color change to determine how much sugar remains. A dark green solution is indicative of less than 0.3% sugar, which we consider dry, while a bright orange is greater than 5.0%. At this point we re-rack the wine into a smaller container in order to get it off the lees and eliminate the head space. We also add more SO2 in order to bind free oxygen, which can aid in spoilage. 

After we re-rack and add sulfites to the wines we move them into a 28 degree storage room,where they will remain for the next four months. This also polymerization process to take place, effectively complexifying the wine. The low temperature also allows potassium bitartrate to precipitate out out of the wine (cold stabilization), while eliminating the chance of the wine spoiling. 

I still get the opportunity to spend my afternoons outside! We are pruning the j-vines in block 20 and 23 this week. As you can see we got a dusting of snow, but this isn't slowing us down. However, we now need to wait until the ground thaws so that we can pin the vines to the ground.

Week 19 (Oct. 28th - Nov. 1st)

Every year 90% of  the new growth needs to be pruned off the vine in order to keep its health in check. This project generally happens in the heart of winter, Jan and Feb, but j-vines like this (ones that aren't cold-tolerant) need to be pruned soon after the first frost, pinned into the ground, and then buried with straw before a true cold sets in. We have therefore begun pruning all of our j-vines and I am patiently learning the art. During pruning one needs to take into account factors like trunk injury, bud positioning, a renewal spur positioning for future years of pruning when determining which shoots/trunks to remove. 

This is the same vine after being pruned. We utilized cane-pruning on this vine, meaning shoots from this year (canes) will be laid down and attached to the fruiting wire in the spring. The alternative method to this is retaining cordons (or extensions of the original trunk) and cutting this year's shoots down to two node "spurs". In either case, this year's growth is saved (either as canes or spurs) because only this wood will produce fruiting shoots next year. The canes/spurs must have substantial wood ripening (periderm/bark formation) in order for the buds to produce viable shoots and clusters. The "primordia" (next years shoots before they begin telescope from the bud) form throughout the entire previous season, therefore it is important that the buds are well exposed to light before they go into dormancy. You can see here that we retained three trunks and five canes. One of these canes (the one that experiences the most winter damage) will be pruned off in the spring, while the other four canes will be attached to the wire, two in each direction. 

This is evidence of winter injury. The pith in the center is dead, along with a wedge of wood. You can tell that this injury happened last winter, as there is a new layer of wood to the exterior of the wedge (this year's growth). I bet that there was a nick in the bark along this section of the trunk which exposed the wood to cold winter air. The circular speckles are also winter injury, representing dead companion cells around what used to be xylem. These cells must have frozen as well, and may even represent years of slight winter injury. 

We need to analyze when malolactic fermentation is complete in all our reds and various whites. MLF is not actually a fermentation, but rather a bacterial inoculation that converts malic acid to lactic acid. This can be beneficial as malic acid is harsh on the palate, where lactic is soft. Also, this process can contribute butterscotch aromas to the wine, which at times is beneficial. Ever notice these buttery notes in your favorite Chardonnay? In order to determine if MF is complete we use a spectrophotomer (light spectrum meter) to measure light absorbency due to concentrations of glucose and fructose, from which malic acid concentrations can be extrapolated. This cuvette contains 100 micro liters of wine and two mL of a buffer solution. We measure how much light is absorbed by this, then add an enzyme and measure it again. The change in asorbance allows us to determine if MLF is complete. Those years of chemistry are finally paying off!

Week 19 (Oct. 21 - 25th)

The ground is finally damp enough to permit us to remove the vines that have been rejected from the breeding program or have died throughout the season. Since decaying roots in the ground can hinder the development of young vines, we use this hydraulic lift (called a Dingo) in order to pull the rest of the plant out of the ground. Grape wood makes great smoking wood, so we are lopping off and saving all the trunks! 

This plant appears to have a healthy root system, so it's fruiting potential must have lead to it's demise. Notice how there are many fine-haired "feeder roots" near the surface and larger "sinker roots" deeper in the soil profile. The feeder root's high surface area allows them to quickly absorb nutrients (with the help of mycorrhizal fungi) and water, while the sinker roots are utilized for carbohydrate winter storage and seeking out water in times of drought. These roots also help stabilize the plant. It's hard to tell in this picture, but you can also see how the roots emerge at each subterranean node and therefore form in tiers. 

The bumps near my thumb are evidence of Crown Gall. This bacterial infection is problematic after hard winters, which cause the sensitive trunks to crack and become exposed to the pathogens. Areas affected by crown gall will eventually die. This can significantly restricts the xylem flow from the roots and eventually will kill the plant. 

I capped off the week Friday by mowing all the aisles one final time for the season. I passed down each row four times in order to ensure that the grass was short enough to discourage mice from making winter homes in the vineyard. If food sources get scarce, mice will resort to eating bark from the vines, effectively girdling the plant. As you can see, we experienced our first hard frost this week as well. This means that all photosynthesis productions is done for the season, all fruit and wood ripening has occurred, and carbohydrate storage has finished. The vines are not going into dormancy, preparing for the long, cold winter ahead. 

Week 18 (Oct. 14 - 18th)

I went on a road trip Saturday to Melrose, MN in order to help John finish harvesting his vineyard.We lugged away 5,000 lbs during the day-long adventure, all of which is being made into wine at the Parley Lake Winery. To conclude and toast the harvest season John "saber-opened" a bottle of champagne, a old tradition of Germany. He used a knife (but traditionally it would have been a sword) to perfectly crack open the bottle top. 

We continue to harvest grapes a the HRC as they continue to ripen and become more palatable. However, grape varieties with thin skins are starting to break down and attract more Asian beetles and wasps! This makes harvesting a slower and more painful process. The chemical in the beetle's hemolymph (orange goo) is supposed to make a wine taste like burnt peanut butter, which apparently is a bad thing. 

We received a few coolers of grapes this week from growers around MN in order to analyze how the chemistry varies between locations (or more specifically soil conditions and cultural practices). I crushed the clusters by hand, collected two viles of the juice for each, and then recorded pH, TA and degrees brix.

As we scour the vineyards for the latest varieties to pick, we are also making sure to find all the breeding bags. These wax-paper bags contain clusters of the grapes which we cross-pollinated by hand back in June. 

Though this project has been on the back-burner for the whole summer, it is the foundation of our breeding program and therefore one of the most important tasks that we will perform each season. We carefully extract the seeds from the pulp, rinse and scarify the seed coats, dry the seeds and rub off leftover sugars, and then count the exact number per cross. Though the seeds all look identical, each has unique and carefully selected genetics that need to be properly recorded. If this part of the process were to be done improperly, the breeding program wouldn't progress for the next two years. The seeds were all counted three times, totaling to a little over 6,000!

Week 17 (Oct. 7 - 11th)

This is a chimeric Frontenac cluster that John found in his personal vineyard. Growers need to watch out for these mutants during harvest because if this happened to be picked along with a batch of Frontenac blanc, the wine would have become a rosé just from these few berries.

This berry was 1/4 noir and 3/4 blanc! Cool, eh?

We get to crush and de-stem small batches by hand. We need to carefully remove as many (hopefully all) asian beetles as possible, as the smell of one crushed beetle can be detected throughout an entire batch of wine. This is a big problem in this day and age for commercial wineries too! Also, notice how the Marquette, and a few other reds, have been pressed and are now in carboys. These will continue to bubble until all sugar has been converted to ethanol and CO2 via the yeast.

A few whites being re-racked before fermented. We add an enzyme after pressing to drop out various proteins, which ends up leaving a sludge on the bottom of the carboy via gravity filtration. We rack the juice off of this before fermentation, then off the yeast after fermentation and maybe once more afterwards. During these stages the amount of air in the carboy above the juice isn't important, but in later stages of re-racking it is important to reduce the "head-space" to as little as possible. 

This machine may look fancy, and I guess it is since it cost more than $5,000, but it is actually pretty simple. It is an automated titrator, so all we need to do is insert the probe and calibrate it to two standards, add 5 mL juice and 45 mL DI H20 to each cup, and then press start. It adds NaOH incrementally, while mixing the solution with a propeller, until it balances the solution. Based off of how much NaOh is used it calculates and prints out a reading of every TA (titratable  (or total) acidity). A normal TA is anywhere 6 - 8 g/L, however our research grapes tend to come in around 10 - 12 (and therefore have a nice acid bite to them!).

Week 16 (Sept. 31 - Oct. 4th)

The yellow jackets have discovered that some grape skins are thinner than others and are therefore easy enough to chew into. This now makes it difficult to harvest, as we have to be careful where we grab the clusters. We have to pick out broken berries with our pickers, since these smell bad (have a high volatile acidity) and will make the wine taste bad. The broken berries are now also attracting flies and asian lady beetles! Yay!

An afternoon project with dad! I was fortunate enough to bring home substantial scrap pieces of trellis in order to build a trellis for my very own, lavish front-yard vineyard. After a few hours of digging and pounding, the trellis is complete and ready to support my six vines!

Jenny came back this week! She had been at home with the baby up until this point, but now the Thull Team is back in action (with their own language and everything!).

While the reds are fermenting, CO2 bubbles cause the skins to rise to the top (above the juice) and form a cap. In order to allow the wine to fully extract the color and flavor we need to "punch down" the cap twice a day. I have had to punch down the various Marquette batches this week. We tested out three different yeast strains, each of which will contribute its own flavors and aromas to the wine. The variation from yeast strain to strain is due to the different types of enzymes that yeast produce. The enzymes are important because they deglucosylate (remove a glucose) flavanols, making their aromas detectable.  

We stepped away from the vineyards and into the pumpkin/squash patches on Tuesday, the 1st, in order to harvest this year's crop. After many hours, and many sore backs, we harvested all 180 varieties totaling to roughly 10,000 lbs. Most of this will go on display in the Landscape Arboretum and sold at "The Apple House," which is a store connected to the research center. This had been Jenny and John's project all year. The effort definitely payed off!

Nick, the winemaker, and I chopped and pressed a few bushels of SweeTango apples on Friday. We ended up having more juice than we needed to run an apple wine test trial, so I was able to bring home a few gallons for myself. One of the many perks of working at the HRC! 

Week 15 (Sept. 23rd - 27th)

This is a clear example of a "bull cane." This shoot is characterized by excessive vegetative growth, which can be caused by various reasons. If soil nitrate levels are too high (or alternatively looking at it, if soil organic matter above 5%) vine shoots can be dominated by bull canes. However, this isn't the case for this vine since we don't fertilize and our organic matter is around three percent. You can see that the right cordon is dead (right above the cane), so therefore all nutrient and water supply from this half of the vine (maybe even a whole second trunk) is fueling the growth of this individual shoot. This may seem like a good thing, and it even looks good since the bull cane is in a perfect spot to renew the dead cordon, however this isn't the case. Bull canes are not winter hardy, because they wont ripen off properly and have big buds, and don't necessarily produce quality fruit. Therefore, these shouldn't be used as fruiting canes, but can temporarily be kept in order to keep vegetative growth in check (just like kicker canes). A goal is to keep fruiting canes smaller than the width of a pencil. 

The patterns on these leave are a result of a bud mutation. Just as bud mutations can change fruit color, so can they alter the chemical make-up of the leaves. These leaves are called chimeras and the white patches are due to the leave's inability to produce chlorophyll in certain areas. Whole shoots can be mutated white, which is bad for plant health because then they become nutrient sinks instead of sources. 

We decided to harvest half of our Marquette early in order to compare it to a second harvest in a few weeks. Of the two clusters per shoot, we alternated picking the top and bottom of each shoot in order to get a representational sample size. Typically the basal most cluster will be farthest along in fruit development since its complimentary leaf will have had the most time to mature (and it is closest to the cordon). Sometimes growers will let their basal clusters hang and remove them later for a reserve wine. These lugs were weighed, destemmed (in the destemmer to the right), fermented in the upside-down white buckets, pressed in our bladder press, racked, sent through malolactic fermentation (in order to add aromas and drop malic acid), reracked again and then aged. 

You can notice the difference in color of the berries that were exposed to the sun verses those that weren't. Fruit exposure to sunlight is important in increasing flanvanols (phenolic compounds which make up the wine's flavor, astringency, complexity, and aging potential). Additionally, exposed berries will have lower levels of acid (both tartaric and malic).  Lesson to be learned: find the Goldilocks. Learn how to expose fruit to the sun so that you can increase the flavors and colors to their maximum potential, while decreasing unpalatable acids.  However, if you leaf thin too much in the wrong places or at the wrong time, then berries may become sun burned and wither out. 

Week 14 (Sept. 16th - 20th)

This is Siegerrebe, my favorite eating grape that's supposed to be a wine grape. It is in the muscat family, so it has flavorful terpene aromas such as linalool and geraniol. We are making it into a sparkling wine. Yum!!

We have begun to replace all the rotting posts throughout the vineyards. We first walked down each row and pushed/pulled every post, listening to see if they cracked. If so, we'd mark them with orange tape. Afterwards, we pulled the staples out, cracked the post off the rest of the way, weaseled the old post stumps up with two shovels, widened the hole if needed, dropped a new post in and stapled the wires back to the posts. We have gotten pretty good at this art over the week. It takes us between 5 and 10 min/post, depending if they're caged like this one. Good thing the posts last close to 25 years!

We replaced a number of end-posts throughout the week as well. This entailed a bit more work: widening the angled holes, replacing anchors and strainers (the winch-like mechanism that I'm tightening here), and retying catch wires. We customized the trellises so that the fruiting wire was at a comfortable picking and pruning height. This happened to be around two and half feet, which allowed just enough space for a canopy of four and a half feet (roughly the shoot height needed to acquire 15 nodes, the number needed to support three clusters).

A Lacrosse news anchor and her husband stopped by on Friday to interview and film shots for a documentary that they are making on Minnesota wineries. It's fun to be in the action of such a novel industry! 

Week 13 (Sept. 9 - 13th)

John displaying the progress made in the roots over the past three months as they followed the water downward. Roots are composed of large arms and branches, root tips and root hairs. Roots are important for water and nutrient uptake, anchoring and carbohydrate reserves for dormancy. The majority of water/nutrient uptake happens in he white (fresh) roots while storage takes place in the roots that have hardened off and formed a periderm. 

This interveinal chlorosis is indicative of a magnesium deficiency. In this case the vine is a mutant and cant uptake the element (I know this because no neighbors displayed these symptoms). 

As we wait for more varieties to ripen we are occupying our time by removing discards. This task is on-going, as Peter is constantly assessing vines that have been planted over the past decade and weening them down to a select few. If he finds a vine that is promising (in growth habits, fruit size and flavor, disease resistance) he will mark it as a watch, and most likely remove its neighbors. Eventually watches are assessed and weened down to a select few. Peter will will give each of these vines a number. Numbered vines are then propogated vegetatively and planted in various locations throughout the vineyards, which have different soil textures, aspects, slopes, organic matter, etc. After years of closely monitoring the numbered vines Peter (and his boss Jim) will select the perfect vines to be named and patented. It is these that are then sold commercially. 

This is characteristic of the grape berry moth. It lays its eggs in the grapes so that the larvae can tunnel their way through berry to berry, forming a connective web between them. These affected berries generally will discolor and shrivel up after being the worm has chewed its way through them. We need to pick these "bad" berries out of the clusters after we harvest them. 

A pristine day for harvesting Edelweiss. This is a V. labrusca flavored grape (like Concord)  that was bred by Elmer Swenson in 1980. Though it was originally bred for wine, many people enjoy the taste and eat it fresh. All of the grapes here will be sold in the Arboretum's Apple House.

Week 12 (Sept. 2 - 6th)

The day has finally come! Harvest season has begun! The much anticipated harvest was kicked off this week with the picking of MN 1259. It is a very early ripener, so we will have to wait a few more weeks to pick he next variety, but the five lugs which we picked from 7 or 8 vines was a successful opener to the season. 

Across the board acid levels are dropping, while sugar levels rise as we progress into late summer. Due to this, I am tempted daily by the luscious, hanging fruit, as this is the first time that they are actually palatable. I find myself mindlessly plucking a berry and popping it into my mouth every few vines, but this isn't always a rewarding act. Within seconds I either pucker, cringe and spit or smile and enjoy the sweet, flavorful fruit. Most varieties by now look ready to pick, but only a few in actuality have reached their desired, full potential. I guess I'll just have to wait to experience the best that the vines can offer! 

In the field we cut each cluster, pick out the bad fruit and shot berries, and then carefully lay them into these yellow lugs. We then transport them to the winery, record their weights by vine, randomly select 50 berries and record their total weight. 

Next we press the fruit. We use this mini bladder press, which is filled with water from a hose. We allow the rubber bladder inside to reach 25 psi (or around 2 bar), release the water, mix up the pomace with our hands, and then do it again. Three presses effectively squeezes out all the juice while retaining the stems, skins and seeds inside. 

Green and orange horn worms like this are becoming problematic in the newly planted vineyards. They are stripping the leaves from the young vines at a rapid rate. We use an integrated form of pest management to control this problem (we squish them). 

We spent the tail end of the week preparing for Saturday, our open house fall tour. We invited close to one hundred local residents and growers so that they could learn about grape growing and breeding, taste grapes, and tour our vineyards. Peter, Raina, and I spent Thursday and Friday collecting three clusters from 75 varieties. The grapes ranged from table grapes to V. vinifera wine grapes to MN wine grapes. It was fun to be able to compare different varieties side-by-side and determine their intricacies in sugars, acids, textures and flavors. I was also able to network a little and meet local grape fanatics like me!