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!).