Good Stuff to Know

Know Your Enemy!

When Spring is in the air, it’s not all a party. For winemakers, spring means the inevitable return of our sworn enemy, Drosophilia melanogaster, (aka—the common fruit fly).

These tiny, flying monkeys of doom are hard to exclude from your winemaking areas, and while they're easy to kill, by the time you've swatted one thirteen more have materialized out of thin air, looking for a free meal. Females lay 400 eggs each, and they mature in as little as 7 days!

The reason why we need to be concerned over the little monsters isn't just that they're unsightly and chewy when you discover one inside a mouthful of Chardonay. No, it's their other name we need to think of, "Vinegar Fly.”

The little blighters are filthy with acetobacteria, the organism that turns our delicious alcohol into vinegar.

How to combat'em? First, understand that they don't eat fruit; they eat mainly yeast. When they smell carbon dioxide and alcohol, they think it's a piece of rotting fruit where they can lay eggs and get a delicious meal. When they smell a fermenting carboy, it's their equivalent of a Vegas buffet ten thousand miles long.

Anybody who has ever worked as a bartender over the summer months knows the sad and icky truth--you come in for the first shift of the day and any bottles that have been left overnight with an open pour-spout ('speed spout') will need to be poured through a coffee filter to extract the little winged corpses from their watery graves.


In managing these horrific little pests is exclusion. You can't keep them out of your house and your fermenting area, so you'll need to exclude them from the wine itself. Always do covered fermentations. The most common fermentation vessel used to start kit wines is a 76 litre bucket with a tight- fitting lid and a port to plug in an airlock. By keeping the wine sealed and airlocked, you'll deny entry.

2) When your wine goes to the carboy, make sure you keep that airlock topped up with water. Some folks use sulphite, but sulphite usually oxidizes off in a few days into plain water. Other folks want the sanitizing power of alcohol and load the airlock up with Everclear or grain alcohol - this only attracts the enemy!

3) You’ll need to wipe up every single little spill of wine or juice immediately, and sulphite the area to prevent any residue from getting a yeast film going on it. Then make sure you wash your cloths or discard your paper towels in a tightly sealed receptacle - the cloth used to wipe up the juice will become a source of attraction.

4) Be sure to wash all racked primary fermenters or carboys (those with sediment and even a small amount of cloudy wine in them) immediately. If you can't get to it right away, pop the bung and airlock on again.

5) If you filter your wine (always a good idea), break down and clean your filter right away, and seal the used pads in a plastic bag before discarding them; they smell just dandy to fruit flies.

Other suggestions:

6) Flypaper only works on fruit flies by accident. Plus, some of the stuff is toxic as all get-out, and not good for winemaking areas. You can set up a wasp trap (available from hardware stores) for them. Normally they're filled with fruit juice or other sweet liquid, but that doesn't impress a fruit fly. Fill it with the magic formula; apple cider vinegar with a couple drops of liquid dish soap. The apple cider vinegar drives them to a gustatory frenzy, while the dish soap removes the surface tension of the liquid: when they fly in and hit it, they drown right away - poof!

7) You can also check out natural pyrethrin-based insecticides; they're made from plant oil, are mostly safe and can be used in food prep areas. Never use any other kid of insecticide around wine or food prep areas! Triple-check to make you've got pyrethrin and not the synthtic pyrethroid, which is much more persistent and a killer. Pyrethroids are bad for the environment and can be toxic to children and pets, especially kitty-cats, who lack the enzyme to break them down, and can rapidly succumb to pyrethroid toxicity. No kitty should be collateral damage to a fruit fly!

Is all the fuss worth it?

NOTE: Cleanly-made kit wines that are fully fermented and sulphited to an appropriate level (follow the manufacturer's instructions) are fairly resistant against colonization by acetobacteria. Sulphite is a good bacterial inhibitor for this organism.

But there's always that chance-- a missed sulphite addition, a little extra oxygen pick-up in fermentation, one lone fruit fly’s wings and ... well that's thirty bottles of wine you can't even pour on your salad (wild acetobacteria fermentations make a kind of vinegar that tastes like nail-polish remover).

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What is Oxidation?

Oxidation is one of the most common problems found in home winemaking. When wine is exposed to oxygen the aroma, flavour and colour begins to degrade. The wine takes on unpleasant aromas such as the smell of sherry or caramel in whites, and wet cardboard with hints of chocolate for reds. During the early stages of oxidation the wine will have a sour taste that evolves to a solvent taste. Although oxidized wines undergo a degree of browning, all wines that show signs of browning are not necessarily oxidized. Browning is a natural part of the aging process and the wine is only oxidized if it is accompanied by the aroma and flavour profile described above.

How did my wine become oxidized and what can I do to prevent it?

There are typically three areas of the home winemaking process where oxidation usually occurs.

1.  The Primary Fermenter - During an active fermentation, yeast utilize the oxygen that is present in the must. While a healthy fermentation is active, there is little fear of oxidation. While the yeast are active they also produce carbon dioxide. Since carbon dioxide is heavier than air, it forms a protective blanket on top of the wine that reduces the chance of oxygen coming in contact with the wine. It is suggested that wines be racked to the carboy while the specific gravity is set to 1.010 since the yeast are still producing carbon dioxide at this point. Wines that ferment dry but remain in the primary run the risk of the protective carbon dioxide blanket dissipating. If this happens, there is a large surface area of wine in contact with oxygen, putting it at risk.

2.  The Carboy - It is advised to top up wines post stabilizing to within two inches of the airlock. This greatly reduces the surface area that oxygen can make contact with.

3.  Bottle Storage - Wine that is bottled should sit upright for one day and then be stored on its side. The wine should be stored in a relatively humid room at 16? C/ 60? F. The humidity will prevent the corks from drying out and allowing a path of oxygen contact. The cooler temperature inhibits oxidation since heat speeds up the process.

What else can I do to avoid oxidation?

Sodium and potassium metabisulphite are not only sanitizers but anti-oxidants. RJ Spagnols wine kits have enough sulphite supplied in the add pack to protect the wine from short term oxidation while allowing it to be consumed early. Those wishing to age their wines long term, should add an extra ¼ teaspoon of sulphite.

Remember to:
  • Rack from the primary to the carboy at a specific gravity of around 1.010
  • Store bottles upright for 1 day, then lay them down in a humid, cool place.
  • Add extra sulphite for longer aging periods.
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Tartrate Crystals And Wine

Tartrate crystals, also called "wine diamonds", are a natural product of the wine. Potassium bitartrate is present in grapes and grape juice, so it will be present in the wine also.

In Europe, these crystals are accepted as a sign that the wine is made in a natural way without over-processing. For these crystals to form, the temperature of the wine has to be low. Also, the higher the alcohol content of a wine, the less soluble the crystals are, so more drop out.
" Wine diamonds' are absolutely harmless, although a superficial glance can alarm people who may think that they are pieces of glass. If you are unsure, dissolve some crystals in hot water for proof.

The way commercial wineries deal with this issue is through cold stabilization. They chill the wine at -2 to -3 degrees for a couple of weeks and filter it while cold.( Tartrate crystals can go back to solution when the temperature goes higher )

If home winemakers do not have the ability to cold stabilize their wine, decanting is an easy option. Put the wine in the refrigerator standing up for a couple of hours, the tartrates will drop to the bottom. Decant it into a different container and serve.

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About Color And Tannin Precipitation Red Wines

1 - What is it?
During the aging process, some red wines may deposit a thin dusting of solid precipitate ( sediment ) on the inside surfaces of the wine bottle.

2 - Where does it come from?
Contrary to what some people may think, this precipitate ( sediment) is not the result of poor filtration, spoilage, re-fermentation of the wine, or any sort of winemaking faults. It is a result of the natural aging process. The same process that makes wine smoother with age causes the precipitate. Tannins, compounds that make some red wines taste astringent in their youth, combine with natural pigments in the wine and precipitate out of the wine as a solid. As the tannins precipitate, the red wine becomes smoother.

3 - Does the precipitation adversely affect the quality of the wine?
No. The precipitation is not a defect in the wine. The wine actually improves and becomes smoother as a result of the precipitation. The wine will remain clear as long as the bottle is not shaken excessively.

4 - Are some red wines more likely to develop precipitate than others?
Although any red wine can precipitate tannins, in general, the fuller bodied, darker colored, more age-worthy wines will precipitate more than lighter, younger-drinking reds. Usually, higher quality wines will be more prone to throwing a precipitate.

5 - What can be done to prevent this precipitation?

Commercial wineries tend to hold their wines in bulk and at refrigeration temperatures for at least a year, allowing much of the precipitation to take place before bottling. This is the only good preventative measure for bottle dusting. Filtration, fining and other treatments will not prevent the precipitate from forming.

6 - What is the best method of serving this wine?

Usually, the precipitate will adhere to the inside surfaces of the bottle, and the wine can be safely poured into glasses. If there is a heavy precipitate, decanting the wine prior to serving is recommended.

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Concerns about Plastic

As many of us are aware, the use of plastic and more specifically the plastic component bisphenol-A (BPA) has become front page news because of its potential health-related side effects. BPA is primarily found in polycarbonate plastic. Polycarbonate is distinguishable by its brilliant clarity, high rigidity, and its shatter-resistance. Some water bottles are made from polycarbonate. After speaking to our suppliers who sell plastic items, Grape Expectations has determined that to the best of our knowledge we DO NOT SELL ANY ITEMS THAT ARE MADE FROM POLYCARBONATE PLASTIC.

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