A Rundown of Making White Wines
OK, here are the procedures, (in this humble narrator's opinion), for making white wine from wine grapes, such as Pinot Gris, Chardonnay, Gewurztraminer and Reisling. This is NOT a comprehensive instruction, but rather a guideline. There is a book by Jon Iverson called Home Winemaking Step by Step which is about 200 pages long which is HIGHLY recommended if you are making wine from wine grapes grown in Oregon and want a complete "how-to" guide. Other than that, this should get you through the basics of it all...
Where did you get your grapes? Good grapes make good wine, and bad grapes make bad wine. In my opinion the grower is making at least 75% of the wine. The winemaker fine-tunes the last 25% of the flavor. If you are buying Chardonnay grapes, Pinot Gris grapes or any of the other wine grapes found locally here in the Northwest, be sure you buy from a reputable grower who knows and tells you about the "brix" (sugar level) and the acidity of the grapes. This is important for later on: I can help you more if I know all your numbers. We sell hydrometers and refractometers (to test sugar levels) and acid test kits (to test acid levels) very inexpensively at the store. Knowing these two things will greatly enhance your ability to make a good wine. We will also do free refractometer tests on your "backyard" clusters if you bring them into the store close to harvest time (early September to mid-October, depending on environmental conditions and altitude, etc.)
Over the past few years, we have been recommending 100 pounds of red grapes for each 5 - 6 gallons of wine that you wish to make. (That's about 20 pounds per gallon of final yield.) (Fo your picking information: one hundred pounds of clusters, picked off a vine, will fill a 24-gallon fermenter, approximately.) We have a reason for recommending this 100 pound level, and it has to do with the racking of the wine later on. If you start with less than 100 pounds, you may encounter oxidation damage later on in your wines as you age it over the winter. Read on.
In the beginning, all white grapes get crushed and destemmed. Sometimes the seller of the grapes will do this for you on site, or - if not - we rent a destemmer/crusher for $22.50 (it is a wise investment if you have over 50 to 60 pounds, trust me). You can also stomp them the old-fashioned way with clean feet in a clean bucket. If you have children, this can be fun (sometimes - remember, kids will get bored and cranky just like adults will, after awhile). But you my throw out more than $22.50 worth of clothes, or use more than $22.50 worth of cleaners trying to unstain their purple feet.... Trying to do it by hand in order to save the money may or may not be worth it in the long run.
Destemming is another matter. It is very, VERY laborious and will lead to splinters under your fingernails, bloody hands and lots of frustration. Again, I recommend the destemmer/crusher, but if you want to try it yourself, plan on ten to twelve man-hours for one hundred pounds of grapes in order to do it properly.
Once they are crushed and you have a big, oozing mass of juice and skins, white grapes get pressed and squeezed immediately; the stems (which have been pulled off by the destemmer) should be layered in the wine press in order to build a "foundation" or a "skeleton" upon which to squeeze the crushed, gooey white grapes. This makes the juice run off more easily than just trying to squeeze wet jelly by itself. You should collect the good clean juice in plastic fermenters right off the bottom of the press , while the skins are quickly compost-bound.
Main Street rents both large presses and small presses for $22.50, OR growers sometimes have the equipment on-site if you are buying their grapes, OR you can squeeze the juice out of the skins with nylon bags, pillow cases, hand strainers, colanders, etc. If you are doing over 30 pounds of grapes, my rental will save you quite a bit of frustration. (Again, trust me....)
You should collect about six to seven gallons of juice. You can put it into an eight-gallon or twelve-gallon primary fermenter. Add EITHER 1/3 tsp. of metabisulfite powder OR 6 to 7 crushed Campden tablets to the juice. If the grapes were questionable/moldy/dirty, add 50% more, or even double the dose, depending on how weird they were. This will kill any alien life forms in the juice. You should also add some nutrients (diammonium phosphate (DAP)) to the must: this will help prevent hydrogen sulfide (rotten egg smell) from forming. Chardonnay juice in particular is very nutrient deficient and needs to have some DAP tossed in almost always. It is inexpensive and could save your wine.
SAFETY NOTE: Be sure to use food-grade plastic fermenters non-food-grade plastics have toxins which can be leached out by alcohol and heat. Food-grade plastics are sold in homebrew stores and restaurant supply stores, while most inexpensive plastic containers (such as found in Home Depot) are NOT food-grade. Be careful and do not use questionable plastic. Main Street sells ONLY food-grade plastics.
At this point here, you will want to test your Brix (sugar) levels and see what your average sugar level is in your juice. You want it to be between 22.5 and 26 Brix. 24 Brix is a good place to be. If you need to add sugar to raise your Brix, call me and I can help you calculate how much you should add, but here is the rule: 0.125 pounds of sugar raises 1 gallon of liquid by 1 Brix.You should ALWAYS add less than you think you need, and then more if necessary. You can always add more sugar, but it is very hard to remove it. A hydrometer can tell you for certain, your taste buds cannot: all grapes taste "sweet." Therefore you should not decide whether or not to add sugar just by taste: use a hydrometer, they are cheap. For well-tended wine varieties (Chardonnay, Gris, etc.) you typically will NOT need to add extra sugar most years here in the Pacific Northwest.
You will also want to know, or test, your acid levels at this point. Grapes grown in Oregon tend to have higher acids due to our climate and environmental conditions. Most white grape wines should fall between .5 parts per thousand and .85 parts per thousand tartaric acid. In Oregon, they usually fall on the higher side. The grapes we bring down from eastern Washington tend to fall on the lower side. As a Standard Procedure, most knowledgable Oregon winemakers will add Malo-lactic bacteria to their wines no matter what. It makes wines taste smoother, softer and more buttery and - maybe even more importantly - it prevents it from starting spontaneously after you bottle. We have more information about ML bacteria here. Malo-lactic bacteria are typically added about three days after the fermentation starts.
If your acid is very high, there are more aggressive chemical ways to precipitate it out. If you acid is too low, you will want to add tartaric acid to your must immediately. If you know you are going to be making a sweet wine, such as a sweet Riesling, then you can leave your acid higher. Acid and sugar balance each other, as we all know from drinking lemonade.
Advanced winemakers will want to know their pH as well, but if you are curious about that, you should be reading Iverson's Winemaking book - pH is beyond the scope of this article.
Cover the fermenter loosely with a lid, or a towel, or Saran Wrap and let sit for 12 to 18 hours, the higher the dose, the longer the wait. You are waiting for a gas to develop and escape out the top, so be sure you do NOT have your lid on airtight. Keep out the fruit flies, but let the sulphite gases escape.
After the day or two of waiting, add your yeast. See my article on yeast starter cultures for an optional procedure to add an extra healthy dose of yeast to your wine. Yeast starters, although never necessary, are always a good idea.
Within 24 hours the "must" will be fermenting away. Cover the fermenter tightly to keep out fruit flies, but let the CO2 gases escape - a good fermenter will allow both of these things to happen. Keep the temperature of a white wine as low as possible: 58 to 65 degrees F. is ideal. The cooler the temp, the more "aromatic" and grapy the wine. Be aware that fermentations are "exothermic" meaning that they produce heat. This will elevate your fermenting wine WARMER than the surrounding air temperature - keep your wine in the coolest room you can find above 55 degrees and watch out for those warm Indian summer days. Cooler is better for whites.....
Sometime about halfway through the fermentation, or even earlier (about three to four days into the active period), is the time to add Malo-Lactic Bacteria, if so desired. In most cases, it will help "smooth out" and soften up the final flavor on your wine, especially if the grapes were grown in Oregon, or other cool-weather states. Please see my link here for more info.
After 5 to 15 days, depending, your hydrometer reading will fall to about 1 degree Brix, or 1.010 specific gravity. If you want your wine to remain slightly sweet, now, is the time to rack the wine off to a six-gallon glass carboy and let sit for about a month while it settles out and begins to clarify. If you want a drier (less sweet) wine, rack off when the hydrometer measure 1.000 (0 Brix), or even less.
If you kow you have more than six gallons at this point, you can put the remaining wine into a gallon jug, or you can rack it initially into a 6.5-gallon glass carboy.
Let the wine sit - above 60 degrees or so - for about four to six weeks, while the yeast begins to settle out and the fermentation comes to a complete halt. Have airlocks on your carboys and jugs. You may see faint signs of a tiny malo-lactic fermentation taking place if you added the bacteria earlier. Eventually, usually within that first month, all activity will come to a halt. You now have a stagnant product with a white layer of yeast built up on the bottom.
After that month, rack your wine into another (second) glass carboy. If you are in a 6.5-gallon carboy, rack down into a six-gallon one. If you are in a six-gallon carboy, rack down into a five-gallon one. Rack carefully and do not splash or run the wine down the wall of the fermenter. When done, try to keep the wine as high into the neck of the fermenter as possible, recombining your wines into fermenters of various sizes, if necessary, to ensure that they are all topped up. Add 1/4 teaspoon of metabisulfite powder, if desired, at this racking to each five gallons of wine. If you are going to add oak, this would probably be the best time to do it. (Note: sweet wines classically are not oaked, many dry white wines are lightly oaked.... Be sure to check out our Information Page on Oaking.)
If you are making a white wine that you may want to sweeten later, now is the time to also add Potassium Sorbate (aka Sorbistat-K) AND metabisulfite to your wine. (Please see our page on stabilizing.) Mix the two chemicals together in a half cup of water or wine, and then add them into your carboy full of wine, and let the wine sit for 4 to 6 months in that fermenter. During those months, now heading through Winter, cooler temperatures are better for the wine, and even as low as 32 degrees F would benefit most wines during this aging period. I keep mine in an unheated garage. Ignore it for those winter months, just making sure the airlocks are secure and filled with water. Do not let your carboy freeze it WILL shatter inot many pieces one cold night. (NOTE: Also do not store wine in areas that have weird smells, such as onions, gasoline, lawn chemicals, etc. They can possibly taint your final product.)
After 4 to 6 months (usually May or June) sample the wine, if desired. Add 1/4 teaspoon meta-bisulfite powder, optionally. Try to keep your carboy topped up as much as possible. Write down your opinions about the sweetness/dryness of the wine. You will appreciate that you did later.
Also check for clarity: hold a candle behind the carboy on a dark night and look for a "halo" around the flame. If you see one, then it is still hazy. If you so desire, now is the time to add a clarifier: come in and talk to me, and I will recommend a great one that should make your wine "star-bright" within a month. NEVER bottle an even slightly hazy wine - you will have "floaters" in your wine bottles within 2 months, guaranteed, and it can look REALLY gross, as well as make your wine taste "yeasty.".
If you are in a six-gallon carboy at this point, you can rack down into a five-gallon carboy and let the wine age and sit for a few more months. If you are already in a five-gallon carboy, youmay want to get ready to bottle it. If you already have added a clarifier, it should be crystal clear by now. If you did not, it still may be crystal clear, or you may want to add a clarifier, now, at this point. (If you add one now, you will need to let it sit another 6 weeks before bottling.)
You can now get ready to bottle the wine.
Many white wines are dry (with no residual sweetness), and they can be bottled with just a small (1/4 teaspoon) addition of potassium metabisulfite on the day you bottle. But some styles, such as Reislings, are sweetened.
To sweeten wines, be sure that you have added the Potassium Sorbate and metabisulfite sometime in the past. If you haven't, do it now. You cannot safely sweeten wine that has not been stabilized. We have a great liquified sugar solution at the store that is non-fermentable and easy to add, or you can boil up your own sugar and water on the stove. If you are doing it that way, boil up a solution of table sugar and water, the proportions don't really matter but be sure that it is heavy on the sugar. Allow to cool. Add "x" amount of the solution to your wine, mix gently and taste. You can do this in the carboy, or, last minute, after you have siphoned your wine to a bottling bucket and are ready to fill bottles. Start small and add carefully - once you over-sweeten it, you can never get it out. It does NOT take very much sugar to sweeten five gallons of wine: somewhere between one tablespoon and a few pounds. Add and taste, add and taste until you think you are getting close. Then slow down and add smaller doses of the sugar solution. Do not taste more than three or four times in a row without eating some bread or a dry cracker to cleanse your mouth - your mouth will become saturated to the sugar and you will most likely over-sweeten by accident.
Once you taste a balance that seems appropriate, bottle your wine.
If you have any questions, or doubts, please be sure to call Main Street at (503) 648-4254, or email me, and I will gladly answer any doubts you have...... Happy vintnering!!!!