Making Wine from Grapes vs Kits

Making Wine from Grapes vs Kits

Wine kits are a great place to start when learning to make wine. They’re inexpensive, pre-stabilized, and come with a great set of instructions to help you through the process. You also need only a minimal amount of equipment. At some point though we all want to graduate kit wine making to making wine from fresh grapes. Winemaker’s Academy member Matt is at this point and wrote in with the following question: I was wondering if there is anything different that has to be done or used, when making wine from grapes as opposed to manufactured kits. -Matt This is a great question as there are a few things that differ between the two methods of making wine. The most obvious is the equipment required to process the fruit. You’ll likely need a crusher / destemmer as well as a grape press, all of which are used to extract the juice from the fruit. The other differences are on a deeper level and this is where I’d like to dive in and explore what the big differences are. You’re In Complete Control The single greatest difference in making wine from grapes versus making a kit wine is that each and every decision is now up to you. Kits are pre-stabilized, all additives pre-measured, yeast pre-determined, and the wine making method completely laid out for you. When you buy grapes to make wine from you just get a pile of grapes. The rest is up to you. Let’s take a look at what this really means. Fruit Processing When you buy a kit you get a box with a big bag of grape juice concentrate. This means that the fruit has been harvested, crushed, de-stemmed, and pressed. That’s a lot of work you will have to do on your own when working with fresh grapes. The equipment required to do all of this can be expensive to purchase, however, it is usually available to rent from a local wine making supply store. The down side to renting is that harvest time comes about only one time each year so you may competing with other wine makers to use the same equipment. Often equipment is rented by the hour so that it can be re-rented to another wine maker the same day. Another great place to gain access to equipment is through a local wine making club. Many clubs have equipment you can use either at a “crush party” or some you can barrow and return. Sugar Content (Brix) When purchasing grapes the ripeness of the fruit is vitally important. As grapes ripen their sugar content increases. Most often the sugar content of grapes is measured with a refractometer that relates sugar content in the units of Brix. Based on the sugar content we can determine what percent alcohol content these grapes are likely to produce. This in turn factors into your yeast choice. If the brix is too low you may have to add sugar to bring up the final alcohol to your desired level. On the other hand if the brix is too high you may have to consider...

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Effects of Fermentation Temperature on Wine

Effects of Fermentation Temperature on Wine

Heat is a catalyst. By definition when it is applied to a chemical reaction or biological process it speeds things up. The same is true for fermentation. The higher your fermentation temperature the faster your yeast will convert sugars into alcohol and carbon dioxide. While this sounds great on the surface you never really want to rush anything when it comes to making wine. Warm fermentations can lack character as well as any terroir you might be hoping to capture in your finished wine. Cooler fermentation temperatures help preserve the uniqueness of your specific fruit and helps the character and terroir shine through. For better or worse cool fermentations take longer to complete. Ideal Wine Fermentation Temperature Ranges According to yeast producer Wyeast red wines should be fermented between 70 and 85 degrees F (20-30 degrees C). You’ll get better color and tannin extraction at the higher end of this spectrum. In this temperature range fruity flavors and aromas don’t get preserved which can be good for a red wine. When fermentation temperatures that approach 90 degrees F though you can run into cooked flavors. White wine fermentation temperatures should be between 45 and 60 degrees F (7-16 degrees C). These lower temperatures help preserve fruitiness and volatile aromatics, characteristics more in line with a white wine. White wine fermentations take longer. Academy member Rob ferments his white wines at 45 – 50 degrees and they can take up to a couple months to complete. Extreme Temperatures Going beyond ideal fermentation temperatures can cause problems. Ferment too hot or too cold and your wine will suffer. Fermentations that get too hot not only ferment too fast but it could lead to “cooked” flavors. Your wine will taste like it was boiled on the stove. Additionally, yeast can only tolerate fermentation temperatures that are so high. Go beyond their maximum temperature tolerance and they’ll die. Keep in mind that the fermentation process is exothermic which means that heat is produced as the yeast are doing their work. So even if your wine is stored where the room temperature is within the ideal temperature range your wine could still over get over heated. At the other extreme if your wine gets too cold your yeast will go dormant. The good news here is that when your fermentation temperature rises again the yeast will  likely wake up again and continue fermenting. Even if they don’t come back you can pitch more yeast and continue where you left off. Your wine won’t get damaged by excessively cold temperatures like it will with excessively warm temperatures. Measuring Fermentation Temperatures The simplest way to monitor your fermentation temperature is to use a sanitized kitchen thermometer. Just open up your fermentation vessel and take a measurement. Be sure to work as quickly as you can to limit the amount of time your wine is exposed to oxygen. Another option is to get a self adhesive temperature strip. It sticks right to the side of your carboy or fermenter and displays the internal temperature. While these aren’t accurate to the tenth of a degree or anything they will at least give...

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Making Sulfite Free Wine

Making Sulfite Free Wine

There is a lot of confusion out there regarding sulfites and what it means to make a “sulfite free” wine.In reality it’s nearly impossible for a wine to be sulfite free as they are a natural biproduct of the fermentation process Beyond the fact that they are naturally produced there is the issue of stability. Sulfites are used to stabilize wine against microbial spoilage and oxidation. Without them our wines become much more vulnerable and can potentially have a shorter shelf life.   Why Make Sulfite Free Wine? By in large there are two main reasons many people opt to make sulfite free wines. First, the belief that sulfites cause headaches. Second, they opt to avoid sulfites in order to minimize the chemicals added to the wine or to make organic wine Sulfites can cause headaches for people that are allergic to them. It turns out that only about one in ten thousand are allergic to sulfites so this isn’t the source of wine related headaches for most people. Organic wines usually have to have a minimal amount of sulfites which cannot be added by the wine maker themselves. They are allowed to have that minimal amount because it is a naturally occurring by-product though. Safe Practices when Making Wine Without Sulfites If you’re careful and pay very special attention to equipment sanitation you can create a sulfite free wine. Because it does not have the added protection your wine will be very susceptible to spoilage bacteria. Here are a few things you can do to maximize your chances of successfully making a sulfite free wine. 1. Consider Pasteurizing Your Fruit Pasteurizing involves heating your wine making fruit to a specific temperature for a specific amount of time such that the majority of micro-organisms are killed off. There are two methods you can follow to pasteurize your fruit. The first is to bring your fruit to a full boil in a pot of water. After it starts boiling remove it from the heat and cool it in an ice bath. The second method involves heating your fruit to 145 degrees Fahrenheit (63 degrees Celsius) and keeping it there for 30 minutes. Again, cool the fruit in an ice bath before moving on. For more information listen to Winemaker’s Academy podcast episode 8. 2. Sanitize all equipment, working surfaces, and your hands very well. I recommend using a commercial grade sanitizing agent such as Star San. You could use potassium metabisulfite but this does increase your chances of unintentionally adding sulfites to your wine. While I’ve had success with Star San when making red and white wines I will warn you that one Academy member has had trouble with Star San causing off colors in his white wines. Do your best to let all of it drip off of your equipment and storage containers to minimize the possibility of this happening. 3. Flush all carboys, bottles, and storage tanks with an inert gas to minimize exposure to ambient air. As you know the air around us is full of yeast and bacteria. These would make themselves right at home in...

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Malolactic Fermentation on Wine Kits?

Malolactic Fermentation on Wine Kits?

Wine kits are great for experimenting. Whether you want to swap out the yeast, try a split fermentation with multiple strains, or use different types of oak kits are the most economical wine making medium to experiment on. Malolactic fermentation, however, is not something that should be experimented with on most wine kits. In fact unless your kit came with malolactic bacteria I suggest steering clear of MLF altogether. Why? What Malolcactic Fermentation Does to Kit Wines Lactic acid bacteria, such as the strain of lactobacillus shown here, consumes malic acid and converts it into lactic acid. By comparison lactic acid is weaker than malic acid which is exactly why you would perform malolactic fermentation in the first place. An overly acidic wine can be put through malolactic fermentation to reduce the total acidity. Most wine kits, however, have been tartrate balanced at the time of manufacture. This process increases the amount of malic acid in the wine making juice. By performing a malolactic fermentation you will not only be reducing an already balanced acidity, you will also be converting the bulk of the acid present into lactic acid. This can drastically lower your acidity and raise the pH, sometimes as high as 3.8. The result will be a flat and uneventful wine. Lactic acid also has a buttery flavor to it that can complement some wine is moderation. Creating a wine that has a majority of lactic acid in it may come out tasting really buttery. Malolactic Bacteria and Sorbate Another measure that kit manufacturers take to prolong the shelf life of their product is adding sorbate to the unfermented juice. Additionally most kits also call for sorbate to be added after primary fermentation to prevent further fermentation once the wine has been bottled. It turns out that malolactic bacteria interacts with sorbate to produce a chemical known has hexadiene. The presence of this in wine causes rotting geranium odors to form. This is both disgusting and cannot be fixed once it sets in. Some wine making sites suggest that you can successfully perform malolactic fermentation on wine kits provided that you delay the addition of sorbate until after malolactic fermentation has completed. This seems risky though given that there may be some sorbate already in there and because there may also be an abundance of malic acid. This is probably something that will vary from one kit manufacturer to another. For more information on malolactic fermentation check out What is Malolactic Fermentation?. Photograph used under Creative Commons licence. Photgraph by:...

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Cork Closures and Oxygenation

Cork Closures and Oxygenation

Natural cork closures have been around for hundreds of years. At first they were merely a more convenient way to seal a bottle of wine. Over time, however, we have come to understand that corks offer an incredible benefit over synthetic closures: micro-oxygenation. That’s right, natural corks allow your wine to get oxidized. While this may seem scary at first it is actually very good for wine in very small doses spread out over very long periods of time. The Key Feature of a Cork Closure Natural corks have pores that wine is able to seep into. This is what causes a cork to swell up and provide a tighter seal against the glass neck of the bottle. Oxygen too is able to penetrate these pores. Thus there is an interface for oxygen and wine to interact. Take a look at the picture on the right. You can see that the Shiraz I made almost a year ago has seeped about a third of way through to the outside world. After that the cork looks pretty much like it did the day I inserted it. It is where the red stops that my wine and oxygen from outside of the bottle are allowed to interact. The rest of the cork pores are full of oxygen. The wine has not seeped uniformly through the cork but it is making its way toward the end. It took nearly a year for the wine to get that far through the cork. In another year it may very well be approaching the end of the cork. As wine makers we try very hard to limit the exposure of our wine to oxygen. After all an oxidized wine turns colors and can pick up off flavors. However, in order for a wine to age properly it does need a very small amount of oxygen. Because the wine and oxygen are only permitted to interact within the very small pores the surface area of the wine is actually very small. This is why red wines are able to be stored for years or even decades and still improve. Storing Wine On Its Side In this second picture you can see how wine affects the swelling of the cork. I’ve just removed this cork from the bottle and the red portion of the cork where the wine has seeped in is a bit larger in diameter than the dry end where the cork screw entered the cork. By storing my wine on its side this cork was kept swollen for a tight seal. It also allowed for some interaction between the wine and oxygen. This is why I prefer natural corks and why wines that are aged any length of time in the bottle will have natural cork closures. There are some synthetic closures that allow for micro-oxygenation but in my opinion there’s no replacement for a natural cork. If you do not store a wine on its side the cork may dry out over time causing it to shrink. As it shrinks the amount of oxygen that is able to pass into your wine increases. Sometimes the...

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Understanding Wine Acidity

Understanding Wine Acidity

Wine Acidity Acidity is a measurement of the quantity of acid present in a wine or must. This is not to be confused with the pH of a wine which is a measurement of the strength of those acids present. Like pH, however, the acidity of a wine goes a long way in determining how a finished wine will taste, feel in your mouth, and how well it will age. Having a low acidity will result in a flat and boring wine while having too much acid can lead to tartness or even a sour wine. However, if you peg the acidity just right you are much more likely to have flavors that pop, good mouthfeel, crispness in white wines, and decent ageability. It takes careful measurements and a keen sense of taste for those acids produced by spoilage organisms. More on this soon. What makes acidity tricky is that not all acids are measurable using the same laboratory methods. This is why acidity is described as three different quantities, titratable, volatile, and total. Titratable Acidity Titratable acidity, sometimes referred to as fixed or erroneously total acidity, is a measurement of the total concentration of titratable acids and free hydrogen ions present in your wine. Total acidity and titratable acidity are not the same thing and the terms should not be used interchangeably. What makes an acid titratable is its ability to be neutralized by adding a base, a laboratory process called titration. To measure this you would take a sample of wine and add to it a reagent, or indicator, which is a chemical that changes color when a specific pH is reached. With this mixture in hand a base of known pH is then added to the mixture. At some point the base will raise teh pH sufficiently to cause the reagent to change color, indicating that you’ve reached a specific pH. The amount of base added mixture required to turn the reagent to its indicator color is then translated to an amount titratable acids in the wine. The most common titratable acids are tartaric, malic, citric, carbonic acid. These acids, along with many more in smaller quantities, either occur naturally in the grapes or are created through the fermentation process. Volatile Acidity Volatile acids are different than titratable acids in that they cannot be measure through a titration but must be quantified using a steam distillation process. In this a sample of wine is exposed to steam which in turn encourages the volatile acids to leave the wine. The steam and the acids that leave the wine sample are then collected through condensation in another container. After a specific quantity of water and acids has been collected that mixture is then tested to determine the concentration of volatile acids. Thus volatile acidity is simply a measure of steam distillable acids present in a wine. Volatile acids are produced through microbial action such as yeast fermentation, malolactic fermentation, and other fermentations carried out by spoilage organisms. The most prominent volatile acid present in wine is acetic acid. Also of importance is lactic acid. Aside from lactic acid the...

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