Midwest Grape and Wine Industry Institute

October 2017 Update

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Join us! Upcoming Events Planned for 2017

October 23 & 24, 2017
Critical Sensory Evaluation of Wines

Educated Consumers

In a growing wine industry, like Iowa and the Upper Midwest, it's important to have open-minded yet knowledgeable consumers. Since consumers really drive the market, it is vital to have their feedback on how winemakers can improve their wines. For this reason, consumers that understand what is a “good” or “bad” wine and how to describe it is the first step to not only reducing the amount of faulted wines, but to also having more educated, effective communication of their likes and dislikes. At the Midwest Grape and Wine Industry Institute, we have developed Critical Sensory Evaluation of Wines, a workshop aimed at consumers to teach people the fundamentals of wine evaluation, what to appropriately expect from various wine styles and how to distinguish if a wine is faulted. It is our goal to train consumers how to better use their noses, eyes and tongues when tasting wines and at the same time promote the industry in the Midwest. It's also a way to introduce you to wines being produced in this new wine region.

Please join us on the evenings of October 23 & 24, 2017 for a Critical Sensory Evaluation of Wines workshop.

This workshop is aimed at wine consumers who want to take their wine tasting skills to the next level.  Interested participants do not need to meet any formal requirements (besides being 21 years of age) to participate except an open mind, an inquisitive nose and a willing palate. Industry members (winemakers, tasting room staff) are invited to attend also. However, it should be noted that although much of the material is the same that is covered in the Intensive Tasting Proficiency Training, there is a consumer focus to this course rather than a production focus.

Participants will learn a variety of skills in wine evaluation in this two-evening workshop to become proficient in tasting wines critically. The workshop begins with the major components in wine including sugars, acids, alcohols and tannins. Exercises will be completed in white and red wine aroma identification, varietal identification, wine flaws and faults, wine scoring methods and regional wine variation. The workshop is $50. Online registration is now available.

Register Online

November 16, 2017
Fine Tuning: Preparing Your Wines for Bottling

Apprenticeship educational credit will be provided for Iowa Wine Grower Association (IWGA) apprenticeship participants.

Plan to join us for a workshop focused on the finer things on November 16, 2017 at the Hansen Agriculture Student Learning Center. Luke Holcombe of Scott Laboratories will lead the one-day workshop. Topics include principles and practices of fining and finishing as well as stability and risk assessment for wines. In a hands-on sensory mini-lab, participants will use a range of finishing tannins, gum arabics/mannoproteins to see first-hand how they can help improve the sensory expression of the wine, mask off-notes, and bring some stability. Participants are encouraged to bring a wine to share (for the mini-lab) that may be in need of improvement or refinement. Finishing product recommendations will be made and group tasting conducted blindly. The afternoon session focuses on principles and practices of wine stability and risk assessment for wines where methodologies can be applied to determine the overall stability of a wine based on its chemistry and processing considerations.  The workshop is $50.  Online registration is now available.

Register Online

Research Highlight

“The final destination of making a good wine from a newly developed grape variety doesn’t happen overnight. The Midwest Grape and Wine Industry Institute is committed to doing research to help the industry navigate this road.”
-Somchai Rice, MGWII Assistant Scientist

Somchai Rice Recently Published in Fermentation

We are pleased to announce Assistant Scientist Somchai Rice has an abstract (Evaluation of Tannins and Anthocyanins in Marquette, Frontenac, and St. Croix Cold-Hardy Grape Cultivars) recently published in Fermentation. Her study compared tannin and pigment content in skins and seeds of three cold-hardy red grape cultivars (Fontenac, Marquette, and St. Croix) at two time points from two locations using the Adams-Harberson (A-H) assay. This is the first evaluation of tannins and pigments in these varietals.  Congratulations, Somchai!

Abstract:  Cold-hardy grape cultivars have become popular in northern regions. Wines from these cultivars are low in tannins and lighter in color compared to Vitis vinifera. The northern regions are striving to enhance desired ”full body” and red color qualities in the wine produced from cold-hardy grapes. The objective of this study was to compare tannin and pigment content in skins and seeds of three cold-hardy red grape cultivars, at two time points, from two locations, using the Adams-Harbertson (A-H) assay. The A-H assay is based on protein precipitation and spectrophotometry. Total tannin concentrations detected in Frontenac, Marquette, and St. Croix berries, ranged from 0.29 to 0.66 mg/berry catechin equivalents (CE). Bitter seed tannins were most abundant in Marquette berries (0.54 _ 0.66 mg/berry CE). Softer skin tannins were most abundant in St. Croix berries (0.24 _ 0.19 mg/berry CE). Monomeric anthocyanins contributed to over 60% of the total color at pH 4.9 and were highest in St. Croix skins (74.21% of the total color at pH 4.9). Varying amounts of short polymeric pigments and long polymeric pigments were present in grape skins, indicating that pigmented tannins had already formed by harvest. This is the first evaluation of tannins and pigments in Frontenac, Marquette, and St. Croix berries.

From the Lab

Malolactic Fermentation Tracking Tip

When tracking malolactic fermentations, remember, the only way to see how fast you're moving is to look at a change over time. Depending on who you ask, many different values for the amount of remaining malic acid may be given as the threshold for considering MLF complete. A wine may be stable at any or all of these values, depending on its other chemical parameters.  It also may or may not still be moving at any of these values. To know whether it is or isn't, you need to compare results from at least two different points in time. If sending samples to the Midwest Grape and Wine Industry Institute for malic acid testing, consider freezing a sample today, taking another sample a week from today, and shipping them together. With a single sample, we can only tell you where you are, but not where you were, where you're going, or how fast you're moving.

Wine Thoughts

What we really need is a way of measuring not just how much tannin a wine has, but how astringent it’s likely to feel. That’s a tall order — astringency is a complicated sensation affected by alcohol concentration, sugars, polysaccharides, the person doing the tasting, and undoubtedly other factors. Just tasting... is without question, the most elegant and reliable way to measure wine astringency. But it would still be useful to have a way of measuring the relative astringency of different types of tannins to correlate with how different production techniques affect those tannins and make some predictions.”
- Erika Szymanski, University of Edinburgh, a blog about wine

Tannin Still a Hot-Button Topic

In July 2014, a research fellow at the University of Edinburgh, Erika Szymanski, wrote on her blog, The Wineoscope, about measuring not only tannin concentration, but tannin behavior. Three years later, tannins are still a hot-button and mysterious topic in both Vitis vinifera-based wines and those made from cold hardy grapes, though they present quite different sets of challenges. Many researchers continue to investigate the “best” way to measure tannins to give winemakers useful information to both reflect wine sensory quality and inform grape-growing and winemaking decisions. (And better yet if we can find a method of testing that’s feasible for winery labs to perform on-site!) This piece does a nice job of introducing some of the issues that make studying tannins so complicated and so important.

In celebration of October and fall colors, let's talk wine color.  Usually, red and white grapes both produce clear juice. The color of red wine is derived when colored pigments are extracted from the grape skins. The intensity of the color can be influenced by the grape variety and/or the duration of the skin contact. Pink or lighter colored wines are created by removing the skins early in the fermentation process.  Happy October, everyone!
For more information on the open position for MGWII Director/Assistant or Associate Professor position, please see
Other Events/News

For more information on upcoming events, please see our events calendar. We have listed our upcoming meetings and workshops there.  Things to note for this fall are:
  • Wine 101 (Wines of Iowa, West Des Moines) - October 16, 2017
  • Critical Sensory Evaluation of Wines - October 23 & 24, 2017 (6 to 9 p.m.)
  • MGWII Advisory Board Meeting – November 9, 2017
  • Fine Tuning: Preparing Wines for Bottling – November 16, 2017
  • Tentative Wine Microbiology workshop - January 4-5, 2018
Mark your calendars. We look forward to seeing many of you soon.
Thanks for your continued interest and support of the Midwest Grape and Wine Industry Institute activities. We value our relationship with you.
Copyright ©  2017 Iowa State University Extension and Outreach, All rights reserved.

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Midwest Grape and Wine Industry Institute
2312 Food Sciences Building
Ames IA 50011

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Midwest Grape and Wine Industry Institute · 2312 Food Sciences Building · 536 Farm House Lane · Ames, IA 50011 · USA

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