The beauty of winemaking is that no matter which side of your brain you use more often, it encompasses both; bringing together the art and the science of winemaking. But here is the real question. How many of our readers make their wine in a scientific fashion? Noting every single detail about your sulfite levels, color of your wine, the taste, the smell and even the location it is stored in? Or are you the type of winemaker that adds sulfite without measuring or doesn’t take notes and just does “what the wine tells them to do”? Keep Reading More!
Sulfur Dioxide, or SO2, is a chemical compound used by winemakers to help keep their wine protected from the negative effects of oxygen exposure as well as spoilage microorganisms. Free SO2 is important for determining preservation ability. Total SO2 is not as important for home winemakers because it is usually measured to fulfill export regulatory requirements. Regular testing for Free SO2 allows for the winemaker to make the necessary additions to the wine to avoid spoilage. Vinmetrica’s SC-100A and SC-300 test for not only Free SO2 but Total SO2 as well, when you purchase separately our 1N NaOH solution. For more information about Free SO2 and Total SO2, check out this link to the MoreWine article: SO2 Management by Shea A.J. Comfort. http://morewinemaking.com/public/pdf/so2.pdf
We’ve been getting a lot of buzz from cider makers the past few weeks asking if our units can test SO2 levels in cider, and they do! We have several customers that use our various instruments to test their cider for SO2 with great success. Using the same method as found in our product manuals, you can test your cider for SO2 the same way you would test your wine!
How does the Vinmetrica SC-300 SO2 and pH/TA Analyzer Kit compare to other Free SO2 testers on the market? Daniel Pambianchi has done some benchmark comparisons between several Free SO2 testers available. He has created a full report outlining the methods, results and his conclusions. Thank you Daniel for your report. We are happy to share this with our customers. Keep Reading More!
By now you may have heard that we just released our newest product, the SC-50 MLF Analyzer. We have been working on this for nearly two years, mainly to be sure that the product is easy to use, reliable and accurate. The approach we took was to have the device measure the increase in CO2 pressure that occurs when malic acid is converted to lactic acid, a process we call ‘Biopressure’. This increase in pressure is then converted to an electrical current that the SC-100 or -300 SO2 analyzers can pick up and display. Pretty simple really, but the devil is in the details as they say. And quite honestly we expect the methods (but not the hardware) to improve over time as we learn new ways to make it even faster to use.
They idea of using pressure to measure malic acid in wine is not new in itself. Over 50 years ago, George Kolar of the Australian Wine Research Institute published an article entitled “Manometric Determination of l(—) Malic Acid in Grape Musts and Wines”* that described a method adapted from earlier biochemical research. This method was adopted widely during the 60s, but was eventually displaced by other analytical techniques, most notably the paper and liquid chromatographic methods, and enzymatic spectrometric assays. All of these later methods were either simpler (paper chromatography) or more accurate and suitable for commercial laboratory use. In contrast, the manometric (i.e., based on measuring gas pressure) method, while sensitive and accurate, involved complex glassware and a good deal of professional training to execute.
We believe that the SC-50 incorporates 21st century technology that makes it a pretty good manometric device that is easy to use; the Biopressure agents, reagents, and methods we have developed over the the last 2 years give Dr. Kolar’s technique an entirely new lease on life. You should be able to complete a few or a few dozen tests in 30 minutes, something that would have taken him (or probably his graduate student, poor soul) hours and hours, 50 years ago.
*Am. J. Enol. Vitic 1962 vol. 13 no. 3 99-104 http://www.ajevonline.org/content/13/3/99.abstract
Vinmetrica specializes in wine testing equipment, but did you know that our instruments can also be used for beer making as well as distilling spirits? During the distillation of whiskey, the water used is the most crucial liquid used for production. It is vital to have water at the proper pH in order to smoothly run through the distillation process of mashing, fermentation, distillation and maturation. All good whiskeys start with the use of good quality water. The water needs to be at the proper pH, lower than pH 7, which is crucial for starch conversion. A distiller must also monitor the pH of the mash. The American Distilling Institute discusses the importance of obtaining and using a good pH meter in their paper, The Craft of Distilling Whiskey (http://www.distilling.com/PDF/craftbook.pdf).
A few months ago a customer purchased one of our SC-200 Kits in the hopes of using it for his up and coming distillery located in Berthoud, Colorado. Being in the heart of one of the largest craft/micro-brewing regions in the United States, the opening of K J Wood Distillers was a nice change and the owner, John Wood, was very welcoming. We always like checking in with our customers but the opportunity to visit one was a special treat. Their grand opening celebration took place on June 27th at their distillery. They offered several types of Gin cocktails ranging from a cucumber soda fizz to a cocktail with habanero peppers. I have never actually tried Gin but have heard that it can be a bit hard to drink. Their “Jinn Gin” was phenomenal. Yes, phenomenal!
During the celebration I was introduced to John’s neighbor who owns a winery, Sweetheart City Wines. After some casual discussion about wineries and wine-making in general, I was taken into his winery itself and given the grand tour. Come to find out he is one of our original customers and owns the original model of the SC-100. These two neighbors both own Vinmetrica SC series systems! One for a winery and one for a distillery. What are the chances of that?
Taylor had a wonderful time visiting K J Wood Distillers and seeing Colorado. I can’t wait to try the whiskey and I hope that their Vinmetrica SC-200 helps them make the best whiskey out there. Thank you to all our customers; from the wineries to the distilleries.
Vinmetrica knows what it takes to make a great wine; it takes hard work and proper testing techniques. Eventually we all learn how to become sommeliers, because, let’s face it, we all like to taste test our wine too! We started Vinmetrica with a desire to make quality devices for wine makers that are accurate, easy to use, and affordable. This stemmed from the fact that we are wine makers ourselves. We have been making wine for many years and we decided to enter two of our wines in the wine competition at the San Diego County Fair.
Our 2009 Merlot was made at home as our first trial with Oak barrels from grapes grown in El Dorado County. This wine received the Silver medal from the San Diego County fair. Our 2011 Merlot was made here at Vinmetrica using grapes from Ramona Valley. We were awarded the gold medal and were given the honor of being the “Best in Class” this year. We attribute our success to regularly testing for sulfite and other analyses for both wines. Rich was surprised and thrilled at the news!
The awards ceremony was on June 29th where Rich received his awards. He was able to taste some of the 300 highly qualified entries in the competition as well as taste locally made cheese. The event was well organized and it was great to see some of our customers thriving in the competition.
We hope to see you all again next year!
Did you know that if you plan on exporting your wine, you are required to present a specific chemical analysis? Vinmetrica is here to help! After a long testing and analysis process, Vinmetrica now has TTB certified laboratory technicians!
The process to obtain this certification was not an easy feat. The Alcohol and Tobacco Tax and Trade Bureau provided us with two standard wine samples, one red and one white. Being TTB certified gives our customers the piece of mind that their wines and spirits are being analyzed properly and according the the industry standard. Some of the analyses we performed for the certification were alcohol by volume, acetic acid, residual sugars, free sulfite, and methanol.
Vinmetrica provides services that give wine makers the confidence that their wine production is running smoothly. Our TTB certification gives you the assurance that our analytical methods are held to the highest standards.
See you in two years TTB!
Malic Acid Test Kit
Vinmetrica is focused on quality, low cost, easy-to-use products for winemakers. That is why we are proud to be introducing our next product this summer. Malic acid testing is notoriously tedious, but we have a better answer. Get ready to free yourself from paper chromatography! Vinmetrica is currently moving into beta testing for the new Malic Acid tester, which will be an add-on for the Vinmetrica SC-300 (and we are working on compatibility with our other units as well). How much time will it save you? In 30 minutes, you will have a quantitative result that lets you know how your malolactic fermentation is going. How easy is it to use? Put your wine sample in our container, cap it and shake, set it aside for 30 minutes and then come back and take a measurement. Simple as that! No toxic volatile chemicals, no waiting to develop paper chromatography, and no mess!
The Vinmetrica analyzers have been revolutionizing wine making practices for the past three years. In the course of product development, we have generated capacity to perform the tests most commonly needed by winemakers. Need to perform a specific test but don’t have the equipment? We are now offering laboratory services for winemakers so they can focus on creating high quality wines. Check out our services page at vinmetrica.com/services for more details. We offer over 20 analyses at reasonable prices. Our services will be performed following the rigorous AOAC and TTB approved wine analysis methods. We are currently being TTB certified. We are offering, for a limited time, a 10% discount on all our laboratory services, upon checkout type in the discount code ‘VINMETRICALABS’ for instant savings!
What’s coming up next from Vinmetrica? Research and development is always ongoing and we have new products in the pipeline for measuring alcohol by volume and residual sugar. Make sure to check out our blog for the latest updates here on our blog, or sign up for our newsletter on the left
At Vinmetrica, our products and services come with a personal touch: we’re winemakers ourselves. With our background in analysis and our passion for making great wine, we believe we can provide the best products and services that any home winemaker or winery could need. Feel free to call us if you have any questions; our technical support and sales team is standing by Monday through Saturday 9am to 6pm (PST)!
A lot of people have asked me, “Hey Rich I have my Free SO2 results, now what do I do with it?”
Now that people are more often testing their sulfite levels in their wines, the results need to be used to the winemaker’s full advantage in protecting their wine from oxidation and spoilage. I would like to bring up the sulfite (SO2) adjustment process since the results gathered from the SC-100, SC-100A or SC-300 need to be crunched by hand or by a calculator to determine how much, if any, sulfite needs to be added to your wine.
How to adjust your sulfite levels: testing and calculating.
Whenever you move your wine from one container to another, or when you are preparing to bottle your wine, it’s important to check and adjust your sulfite (SO2) levels. What is the right level? It depends on the pH of your wine. The key parameter in protecting wine is “Molecular SO2” which for most wines following primary fermentation, should be at 0.8 ppm (mg/L). This in turn depends on the “Free SO2” (it can also be referred to as “unbound” SO2) and the pH, both of which can be measured with the Vinmetrica wine analyzers. Overall, you can reach your target Molecular SO2 by measuring and adjusting your free sulfite levels and considering your wine’s particular pH.
Measuring SO2: the Vinmetrica SC-100A and SC-300 help you to do this with confidence. But whatever methods you use, keep a few things in mind.
The key thing to check is accuracy. How do you know if your results are accurate? If you are using Aeration oxidation, you need to be sure that your NaOH titrant is standardized. A solution of sodium hydroxide loses strength over time because CO2 in the air reacts with it. Similarly, the 0.02N iodine solution that many use for Ripper titrations can undergo significant loss over time, even a relatively short period of time like 6 months. For Ripper-based methods, you can use the vitamin C trick that we recommend for Vinmetrica’s SO2 tests (although these are generally run for confidence-building, as it turns out that our reagents are very stable.)
But, you might ask, why not just make a standard solution of, say, 50 ppm SO2 from metabisulfite and analyze that to check accuracy? In principle you could do this – for example, you could weigh out fresh potassium metabisulfite (K2S2O5) accurately and dissolve it in pure water to make a 1.0% solution. This would be 10 g/L * 0.57 g SO2/g K2S2O5 = 5.7 g SO2/L = 5700 mg/L = 5700 ppm SO2. Then you could dilute this 100-fold in pure water to make a 57 ppm test solution. Here’s the problem: unless meticulous measures are taken, “pure” water is usually saturated with atmospheric oxygen, and at room temperature this level is about 8 mg/L. Each mg of oxygen will react with 4 mg of SO2, so at 8 mg/L, our water can already eat up 32 mg/L of SO2. Thus our 57 ppm (57 mg/L) SO2 solution will quickly become as low as 25 ppm. As you can see this conundrum is what brought us to use and adopt the vitamin C trick to check our SO2 reagents.
So go ahead, measure the pH and take your Free SO2 result, both can be measured with the SC-300. Make sure to write this info down! Now then, typically, if you have a higher pH wine (lower acidity), you need to add more sulfite (SO2) to achieve the Molecular SO2 level of 0.8 ppm (mg/L). The Table and graph below show the relationship between pH and Free SO2 to achieve this 0.8 ppm (mg/L) Molecular SO2. The Free SO2 on the left side of the graph indicates the Free SO2 you will NEED to achieve 0.8 mg/l Molecular SO2 in your wine. This will be made up of the Free SO2 you currently have now plus whatever you may need to add. So if your Free SO2 results (measured using Vinmetrica’s method or an alternative method) matches the Free SO2 level on the graph or table at your known pH, then you are good, no need to add more sulfite at this time. If it is not you just have to work a little harder to get it there. If your Free SO2 results are below this Free SO2 level you will need to add some sulfite to achieve this level of antimicrobial & oxidative protection for your wine. The amount you add can be determined with a sulfite calculator, which we will talk about next.
The Graph above shows the relationship of Free SO2 and pH required to achieve the 0.8 mg/L Molecular SO2. Molecular SO2 is the active form of Sulfite (SO2) which will protect your wine from oxidation and spoilage.
Table of Free SO2 concentrations necessary to attain 0.8 mg/L Molecular SO2 at a designated pH.
|pH||Free SO2 ppm (mg/L)|
Wait I have to do this by hand? No fear not, that is what the sulfite calculator is for! Winemaker Magazine’s website provides a great calculator and except for some tweaks, which we will talk about below, the instructions are pretty clear.
Once you know your sulfite levels, it’s easy to make any adjustments that may be necessary. The table and graph above is there to guide you in this, but we always like to use the sulfite calculators that are available for download or on the web as applications. My favorite is the Winemaker Magazine Sulfite calculator on the web:
This is easy to use and is accompanied by a nice guide. However a few notes are in order:
1. I highly recommend you choose (and use) “10% Sulfite Solution” from the drop-down menu next to the prompt “Preferred method of Sulfite addition”. (The guide tells you how to prepare the 10% solution. The sulfite solution we’re talking about is potassium metabisulfite (KMBS), though if you choose to use sodium metabisulfite or other sulfite forms, the accuracy is not too bad.).
2. Choose the wine type (red or white). Keep the desired molecular SO2 at 0.8 and enter your wine’s pH value (hit your keyboard’s “Enter” button after entering the value).
3. This is the one step that is not obvious at first (at least it wasn’t to me). After you enter your wine’s pH and the molecular SO2 level, you will see a recommended free SO2 level in the “Notes:” section, just below the entry fields. Enter this number in the “Desired level of free SO2” field. If you don’t see anything in the “Notes” section, enter a “guess” number higher than your current level in the “Desired level of free SO2” field (and see step 6!).
4. Next you enter the “Current level of free SO2” (What you have just measured), and the “Volume of wine to be corrected”, being sure to indicate liters or gallons as appropriate.
5. Now by pressing the “Calculate” button below, you should see a figure under “Amount of sulfite to be added in milliliters (if you used Liters for the wine volume) or fluid ounces (if you used Gallons).
6. If you entered a “guess” number in step 3, you now should see the recommended level in the Notes: section – so enter this and repeat the calculation.
Simple as that! Now that you have protected your wine from oxidation and spoilage, seal up your container and take a siesta. But remember to check your wine for sulfite regularly, especially after you transfer your wine to a new container or are about to bottle!