Aug 22 2009
Best Home Winemaking Articles
Sulfites – What are They? Do you need to Use Them? Why?
(a supplement to The Complete Illustrated Guide to Homemade Wine)
Sulfites are a naturally occurring compound that nature uses to
prevent microbial growth. They are found on grapes, onions, garlic,
and on many other growing plants. No wine can ever be “sulfite
free”, since they come in with the grapes. So – you will have
sulfites in your wine no matter what.
Why Add Sulfites to Wine?
Winemakers have been adding additional sulfites to wines for
thousands of years. The Greeks and Romans used sulfur candles to
sterilize their wine barrels and amphorae. Sulfur protects damage
to the wine by oxygen, and helps prevent organisms from growing in
the wine. This allows the wine to “last longer” too, which lets it
age and develop all of those complex flavors we all love and enjoy
so much. If you didn’t add sulfites, the wine would turn into
vinegar in a matter of months.
Sources of Sulfites
There are basically 2 sources that you can get online or at a local
wine/brew shop. One is potassium metabisulfate and the other is
the easy one: Campden Tablets.
How Much Sulfite to Add?
Most wine recipes call for adding sulfites BEFORE you add the
yeast. The idea is to completely sterilize your must and kill any
bacteria or other things that may have a chance to take hold and
start growing during the fermentation process.
Most recipes call for 1 campden tablet for each gallon of wine at
each racking. I have tried this over and over and using this type
of concentration, you will have wine that has a BAD sulfurous
taste. This is one of the BIGGEST MISTAKES that home winemakers
make. It usually results in pouring out the batch because it
tastes so bad. The amount needed to actually protect the wine
while staying below the TASTE threshold is a fine line. I use ½
campden tablet per gallon and have never had a problem so I
recommend the same.
What to do if you use Too Much Sulfite
This is an easy fix that I discovered recently. Since the reason
you put sulfites in wine is to protect the wine from growing things
and oxidation (exposure to oxygen), then, it follows, that if you
expose the wine to oxygen, some of the sulfites will evaporate. All
you have to do is Rack the wine into another clean container but
splash it all over the place while doing so.
Let it sit for a few days and then rack it back, again,
splashing the wine all over the place instead of “quietly” racking
it.
A few times back and forth, splashing as you go, should get rid of
a lot of the sulfites and make your wine taste as good as ever!
Corking and Corks
By Mike Carraway
Standard wine corks are sold in large, sealed polyethylene bags containing one thousand corks. The corks are sterilized with sulfur dioxide gas when packaged, and the corks remain in a sterile condition until the bag is opened.
The water content of the corks is carefully adjusted just before packaging, and the humidity in the bags is carefully controlled.
Corks taken from a sealed bag are soft, pliable and resilient. They can be driven easily, and the soft, pliable corks quickly conform to the neck of the bottle and form a tight seal.
Unfortunately, for us home winemakers, 1,000 corks is overkill. You can usually buy 25 or 100 at a wine shop or on the internet.
Dry corks should be driven into the bottle whenever possible, but many small corking machines cannot adequately compress hard, dry corks. Then you have little recourse, and softening the corks is necessary.
The normal procedure is to soak hard corks in cold water until they become soft enough to drive with the corker available.
A pinch of sulfite can be added to the water to help sterilize the corks as they are soaking.
Very wet corks are undesirable because excessive “cork water” will be left when the corks are driven into the bottle. Cork water can be avoided by soaking the corks for a few hours, and then covering the corks with a clean cloth and drained overnight.
Corks can be quickly softened (and probably sterilized) in a microwave oven. However, corks burn easily, so some practice is needed.
First the corks are rinsed in clean water and then sealed a plastic, zip-lock storage bag. The sealed bag is then placed in a microwave oven.
You will need to experiment with the time and power settings.
Corking machines should be adjusted so the top of the cork is set just below the lip of the bottle.
Spilled wine should be removed from the outside surface of the bottles when the corking operation is completed because wine left on the glass makes labels difficult to apply.
Mold often grows on the spilled wine, and after a few weeks an unsightly residue can form on the bottle. Remember: Keep it CLEAN!
If you have found this content and previous articles usefull,
you might consider the ” complete illustrated guide to wine making” by Mike Carraway…you can read about it at the following link…
Complete Wine Making Guide
More subtle flavors for your homemade wine
There are many videos and online guides on the internet on making wine from concentrated grape juice from the store. But – have you ever tasted the stuff? Not too good. Sure – it’s wine, but it’s nothing like what you would get at a wine shop.
It’s thin, it’s acidic, and really just tastes like grape juice with a little alcohol in it. Not exactly what you would call a quality wine.
But, there IS a way to improve upon this flavor significantly. How do you do it?
First of all, find a wine from a wine shop that you really like. Many of these wines will list the subtle flavors that the wine has on the label. Examples of this are “hints of pepper”, and “blackberry overtones”. Concord juice concentrate has none of these.
So here’s the secret: Add these things to your grape juice before you start the fermentation, i.e., before you put your yeast in.
If you want “Blackberry overtones”, either buy fresh blackberries at the store, or you can even use canned blackberries in water. Be sure and crush them up to extract the juice or you can even use a juicer to get the juice out. You may want to thin the juice out a little by adding some water and then boiling on the stove to sterilize.
Another thing to add is regular raisins. Get a box of raisins, chop them up, and then boil them in water on the stove to extract the natural grape flavor and the tannins. Tannins are a big ingredient in finer wines and if there aren’t enough, your wine won’t have the right amount of “bite”.
One thing to watch out for: preservatives. If you buy juice or canned fruits, be sure and read the label to make sure there are NO preservatives. Preservatives will keep the juice from fermenting.
What about the “hint of pepper”? Simple, get some black peppercorns and put them in water and boil them to extract that peppery flavor.
You can even put everything above into one pot on the stove, boil it, let it cool, strain it, and then put it into the concord grape juice. Once you have done all of this, you are ready to throw in the yeast and let it ferment.
You will be amazed at the difference in flavor you’ll get. Try it and feel free to experiment by adding other fruits to the concord grape juice. Be sure and keep good notes just in case you hit on the “perfect” recipe so you can reproduce it later.
more information at the complete guide to wine making, and the winemaker’s inner circle.
The Role of Acids in Wine
“article from grapestompers.com”
Before we jump into our discussion of how to measure acidity in wine, it’s paramount to first understand why acid levels are important to the winemaker.
Acidity provides the crisp, slightly tart taste of wine on your palate. Too little acid, and your wine tastes flabby and non-committal. Too much acid, and your taste buds scream for relief. When acids are properly countered by the other ingredients in wine (such as alcohol, sugars, trace minerals, etc.), the wine is said to be “in balance”, which is the desired end result of all winemakers.
Now that you know how acids impact a wine’s taste, which acids are found in wine? Acids are present in wine in many forms, but the largest percentage of acidity (at least in wine made from grapes) comes from three primary types of acid:
Tartaric acid
Malic acid
Citric acid
You may have seen or heard of a product called acid blend*, which is nothing more than a powdered mixture of the three acids listed above. If after conducting an acidity test of your wine, you discover that your wine lacks the correct amount of acid, the simplest solution would be to add an appropriate amount of acid blend to your must prior to fermentation. But we can’t do that unless we know our desired acid levels.
Recommended Acidity Levels
Since each style of wine (red vs. white; sweet vs. dry) is made to taste different, it makes sense that each wine style would have its own range of recommended acid levels.
The chart below provides guidelines for acidity based on the type of wine you are making. Individual tastes vary, of course, so the information shown are recommendations only:
Wine Style
Recommended Acidity Range
Dry White Wine
0.65 % – 0.75 %
Sweet White Wine
0.70 % – 0.85 %
Dry Red Wine
0.60 % – 0.70 %
Sweet Red Wine
0.65 % – 0.80 %
Sherry Grape Wines
0.50 % – 0.60 %
Non-grape White Wines
0.55 % – 0.65 %
Non-grape Red Wines
0.50 % – 0.60 %
*The chart above was provided by Jack Keller’s terrific winemaking web site
The numbers in the chart represent total acidity as a percentage by volume; winemakers refer to this as the titratable acidity, or T.A. for short.
If you’re making wine from a grape concentrate kit like the ones sold on this site, you won’t have to fiddle with measuring and adjusting acidity and pH. This has already been done for you by the kit manufacturer – the grape juice is already chemically balanced. On the other hand, if you make wine from scratch, read on to learn more…
There are two basic ways to measure acidity: measure it with a titration kit or a pH meter. Next, we’ll explain how to perform each test.
How to Measure Acidity Using a Titration Kit
One of the simplest and most effective ways to measure T.A. in wine is by the titration method, which uses an inexpensive titration or acid test kit. These test kits can be purchased for as little as $6.00 (see our Item #2716) and can be used over and over again.
If you took chemistry in high school, you’ll probably remember that titration is a process where you determine the concentration of an unknown substance in a liquid (in our case, we are looking for the amount of acid in must or wine) by slowly adding a small amount of reagent (a base called sodium hydroxide – NaOH – whose chemical concentration is known) until a change in color occurs due to the presence of an indicator (phenolphthalein).
To begin the test, you will draw a 15 cc sample (one cc equals one ml) of must into a test tube. Most test tubes that come with the acid test kits are marked with a line indicating this volume. If not, no sweat. Just use a small plastic syringe (provided) to precisely measure the desired amount into the test tube, and be sure to rinse the syringe afterwards.
Next, put about 3 drops of phenolphthalein indicating solution into the test tube. Swirl or shake the test tube so the indicator is mixed in with the must.
Using the syringe, draw out 10 cc of reagent (sodium hydroxide), making sure there are no bubbles in the liquid. Be careful to avoid contact with your skin or eyes. This NaOH stuff burns something awful!
Very carefully, add the sodium hydroxide to the test tube 0.5 cc at a time. After each addition, swirl or shake the test tube to mix the contents together. You’ll notice that the color of the liquid will momentarily change upon the addition of reagent. If you are testing white wines, the color change will be pink; if testing reds, the color change will be gray. Just swirl and swirl until the color subsides. So long as the color of the must goes back to the original color, repeat this step until the color change is permanent.
When the color (either pink or gray) DOESN’T go away, stop and determine the amount of reagent used. From here, it is very simple to determine the acidity of your must. For each cc of reagent used, this equals 0.1 % TA.
For example, if you used 6 cc of sodium hydroxide to react with the must, the titratable acidity of your must is 0.6 %.
Pretty simple, eh? Just remember to throw away your sample, since this stuff is toxic. DO NOT add it back into your must or wine.
Lastly, wash and dry your test equipment before storing it away.
If you ever run out of sodium hydroxide or phenolphthalein, just ask for Item #2717 or #2716P, respectively.
How to Measure Acidity Using a pH Meter
Measuring acidity in wine using a pH meter is very similar to the titration method explained above, but with a twist: Instead of looking for a color change (which can be very difficult to determine depending upon the color of your wine) to indicate the titration is complete, you simply add the reagent a drop or two at a time until your pH meter reads 8.2.
Why 8.2? This is the same pH at which phenolphthalein changes color.
If you can afford a pH meter (they can be bought for as little as $50 or so), this method is a much more accurate way to measure acidity than the straight titration explanation above. But pH meters are finicky things, so handle them with care:
Don’t drop the meter or otherwise damage the probe
Keep the probe clean and free of debris
Always calibrate your meter with fresh buffering solution before each test
Be sure to stir the sample thoroughly after each addition of the reagent
Store your pH meter in the manner recommended by the manufacturer, especially regarding the care of the probe
If you take good care of your pH meter, it should last a long time.
Adjusting Acidity Levels in Wine
Once testing is complete, you will know what your acid levels are. Compare this value with the suggested T.A. ranges in the chart shown above.
If you need to increase acidity:
Add acid blend (Item #2729 [1 lb.] or Item #2730 [3 oz.]) to increase acidity.
3.9 grams of acid blend will raise the acidity of ONE gallon of must by 0.1 %.
As a helpful hint for those who do not have scales, 1/4 teaspoon of acid blend weighs approximately 1.2 grams; a teaspoon weighs about 5.1 grams.
If you need to decrease acidity:
Add calcium carbonate (Item #2748) to lower acidity, but only to reduce acidity by 0.4 % or less.
2.5 grams of calcium carbonate (commonly referred to as chalk) will lower T.A. of ONE gallon of must by approximately 0.1 %.
Alternatively, you can add a chemical called Acidex in place of calcium carbonate. Refer to the manufacturer’s instructions for proper dosage.
One-fourth of a teaspoon of calcium carbonate weighs about 0.5 grams; one teaspoon of calcium carbonate weighs about 2.6 grams.
General tips:
Until you get the hang of it, test your must twice to be sure of an accurate reading.
If you need to make an adjustment to the must based on your testing, go slow and lean when adding acid blend or calcium carbonate (as the case dictates). You can ALWAYS add more chemicals to make further adjustments, but if you overshoot your mark it’s difficult to take it out!
Take a follow up sample to see how your adjustment went.
Keep good records so you can duplicate or adjust future batches of wine.
