our home wine makers who want to improve on their craftsmanship let's discuss the ten winemaking mistakes.
1. Inadequate Equipment
Winemaking equipment, such as pails, carboys and spoons often seem similar to items that may be around the home. However, in many cases, proper winemaking equipment and utensils are made of special materials and this can influence your finished product.
Re-using plastic pails from other sources, like buckets that previously held food products, is always a mistake. The food odors will have sunk into the plastic, and will taint the wine. Also, plastic items not intended for food purposes, such as brand-new garbage pails must never be used for winemaking. The pigments, UV protectants and plasticizers (chemicals used to keep the plastic from becoming brittle) will leach into the wine, and could affect your health.
We will gladly direct you to equipment appropriate for winemaking. Saving a few dollars by using suspect equipment is not worth it.
2. Cleaning and Sanitation
90% of all winemaking failures can be traced to a lapse in cleaning or sanitation. Cleaning is removing visible dirt and residue from your equipment. Sanitizing is treating that equipment with a chemical that will eliminate, or prevent the growth of spoilage organisms.
Everything that comes in contact with your wine must be clean, and properly sanitized, from the thermometer to the carboy, from the siphon hose to the bung and airlock. One single lapse could cause a failure of your batch.
3. Failure to Follow Instructions
Wine kit instructions may seem to be long and complicated, and the urge is to simplify them, or to standardize steps between different kits. This is always a mistake, for several reasons.
First, the kit instructions are based both on sound winemaking techniques, and empirical trials. This means that not only did some egghead write the instructions based on book learning, he made his assistants actually follow the instructions to the letter, hundreds of times, to make sure they worked.
Second, if your kit fails to ferment correctly, or clear sufficiently, there may be no easy way to correct it if you have not followed the directions.
This is sometimes a problem in that kit instructions are very different from those for wines made from fresh grapes. Trying to use the techniques described in winemaking textbooks will usually lead to problems: wine kits are another kettle of fish entirely.
4. Bad Water
Water is not quite as critical as many people think. In fact, if your water is fit to drink, it is usually just fine for winemaking. However, if your water has a lot of hardness or a high mineral content, especially iron, it could lead to permanent haze or off flavors. Also, if your house is equipped with a salt-exchange water softener, that water can’t be used for winemaking. If you’re in doubt, go ahead and use bottled spring (not distilled) water to make your wine: you’ll appreciate the difference.
5. Poor Yeast Handling
If you look at the instructions in your wine kit (and please, do), they will likely instruct you to sprinkle your packet of yeast directly on to the must. Yet if you read the yeast package (and many winemaking textbooks) they recommend rehydrating the yeast. If the objective is to deliver the maximum number of yeast cells to the must, which technique is best?
It turns out that the answer is not as simple as one or the other. When performed correctly, rehydrating gives the highest live cell counts, and the quickest, most thorough fermentation. The catch is, it has to be done precisely correctly. Lalvin EC 1118 champagne yeast, for instance, asks you to add the yeast to 10 times its weight in water at 40º–43ºC (104º–109ºF).
Breaking it down, the amount of ’10 times’ is important if you’re trying to maximize live cell counts. That’s because the yeast is dried on a substrate of nutrients and sugars. At a ratio of 10:1 water/yeast, the osmotic pressure allows for maximum nutrient uptake (osmotic pressure is influenced by the dissolved solids in the water, like nutrients and sugars). If too much water is used, the yeast will grow only sluggishly. If too little water is used, the cells may burst from the flood of liquid and nutrients forced into them.
Secondly, the temperature range is inflexible. The outer wall of a yeast cell is made up of two layers of fatty acids. These layers soften best in warm water, much as greasy film will come off of dishes best in warm water. Once it has softened up, it will allow the passage of nutrients and waste products in and out of the cell much more efficiently. If the water isn’t warm enough, the cell won’t soften. If it’s too warm, generally anywhere above 52ºC (125.6ºF) the yeast cell will cook and die.
The next thing you have to worry about is temperature shear. Yeast is terrifically sensitive to environmental conditions. If it goes too quickly from a favorable temperature to a less favorable one, weakened cells may die, and others may go dormant, in an attempt to ride out the temperature shift. This reduces the numbers of live, viable cells available to ferment the must, and gives spoilage organisms a chance to get a foothold, and potentially ruin your wine. So if you are rehydrating your yeast, you’ll have to wait as the yeast cools to within two degrees of your must temperature before adding it: accuracy counts!
On the other hand, simply dumping the yeast onto the top of the must should result in lower cell counts. Empirical evidence shows this isn’t the case: the yeast appear to know what they’re doing. Generally, a five-gram packet of yeast will have less than a six-hour lag phase on an average wine kit. This is perfectly acceptable, and isn’t long enough to allow spoilage organisms to get a foothold in your wine. Plus, it’s a heck of a lot simpler than going through the rehydrating process, fraught as it is with risks.
You can rehydrate your yeast if you absolutely want to, but be sure to do it accurately and precisely. The rest of us will tear open the package and dump it in, and spend the extra time sampling our last batch!
6. Poor Temperature Control
Kit instructions tell you to ferment your wine within a specific temperature range. We recommend 20° – 25°C (70°F to 77°F). Yeast thrives between these temperatures. This is one of the situations where s wine kits instructions are different than commercial wine making techniques. In commercial wineries, some white wines are fermented cooler than this, sometimes below 55°F. Commercial wineries have the luxury of process control and taking a year (or two, or three) before they bottle their wines, so they don’t face the home wine makers’ issues. For you namely, if the fermentation area is too cool the wine will ferment very slowly. This will lead to an excess of CO2 gas (fizz) in the wine, and it may not be ready to stabilize and fine on the appropriate day. Even worse, the kind of fining agents included with wine kits don’t work well at temperatures outside of the 20° – 25°C (70°F to 77°F) range. Below 19°C (68°F) your wine kit may not clear at all!
7. Adding Sulphite and Sorbate at the wrong time
Sulphite and Sorbate, the stabilizers in the kit work to inhibit yeast activity. If, by mistake, you add them too early your wine may not finish fermenting. If you add the sorbate on day one, the yeast will never become active, and the kit will not ferment.
8. Leaving out the Sulphite
Some people believe that they are allergic to sulphites, and want to leave them out of their kits. While this is their option, it’s a bad idea. True sulphite allergies are terrifically rare, and if someone has a reaction to drinking wine, it’s almost always due to some other cause. Besides, yeast make sulphites themselves during fermentation, so no wine can ever be sulphite-free, no matter what.
Without added sulphites the kit will oxidize and spoil very rapidly. It will start to go off in less than 4 weeks, and be undrinkable in less than three months. Also, if the sulphite is left out, but the sorbate is added, the wine will be attacked by lactic bacteria, which will convert the sorbate into the compound hexadienol, which smells like rotting geraniums and dead fish.
The bottom line is this: if you do not add the sulphite to the kit,no one can guarantee the wine, so think carefully before you do it.
9. Not Stirring
On day one, the kit needs to be stirred very vigorously. This is because the juice and concentrate are very viscous, and don’t mix easily with water. Even if it seems that dumping the contents of the bag into the primary with the water has done the job, it hasn’t. The juice lies on the bottom of the pail, with a layer of water on top, throwing off any gravity readings, and making the yeast work extra hard.
When it comes time to stabilize and fine the wine, it has to be stirred vigorously enough to drive off all of the CO2 it accumulated during fermentation. This is because the dissolved gas will attach to the fining agents, preventing them from settling out. You need to stir hard enough to make the wine foam, and keep stirring until it will no longer foam. Only then will the gas be driven off so the fining agents can work their magic.
10. Not Waiting
Wine kits are ready to bottle in 4 to 8 weeks depending on the kit; they’re not ready to drink! If you really, really can’t wait, the minimum time before a kit tastes good is about two weeks. This is long enough for the wine to get over the shock of bottling, and begin opening up to release its aromas and flavors. Three months is much better, and the wine will show most of its character at this point. For most whites, however, and virtually all reds, six months is needed to smooth out the wine and allow it to express mature character. Heavy reds will continue to improve for at least a year, rewarding your patience with delicious bouquet.