Making White Wine – Kimo’s Method

First Things First

I know this is not the “safest” way to make wine. I let my juice oxidize (turn brown) and keep the juice at low temperatures, instead of adding Potassium Metabisulfite (KMBS), as the juice is being extracted. I know winemakers who make a KMBS solution (20-50ppm) to add as juice is being pumped into tanks; but they are playing it safe because they are working with hundreds of gallons at commercial wineries. If you doubt your skills or don’t have enough time to stay on top of the wine for 10+ days, I would suggest you play it safe and add KMBS to the pressed juice as you are transferring it to tanks or barrels. Also, I use this same white wine process for making rosé wines.

My favorite site (because it is easy to remember) for wine calculators is WineBusiness. But VinoEnology is the site that created the calculators. As a winery manager, I used the Wine Business site several times per week and that is why I can easily remember it. You should learn what these calculators can do for you.

Before I get into my process for making white wine, I would like to acknowledge Heather Pyle, one of California’s best winemakers, for all I learned from her at The Lucas Winery. And if you are really interested in being a professional winemaker, consider enrolling in the U.C. Davis winemaking program. It is a costly, intense online program with great professors, but it covers everything from viticulture to bottling. If you have not taken chemistry in college, they now have remedial courses available. It would also be good if you have a bit of cellular biology knowledge. There is usually a wait list to be accepted in the program and your classmates are from around the world, which makes for a very interesting experience.

Preparing for Harvest

Make sure you have at least 3@ 1 gallon water jugs frozen for every 40 gallons of anticipated juice. Make sure the labels and any glue residue are removed from the jugs. Also, spray the water jugs with Star-San before they are frozen and again before they are placed in freshly-pressed juice. If there is any doubt about a container’s integrity, do not use it. Buy cheap water at a “dollar store” because it will be disposed of after your season’s wines (including any reds) are fully fermented. The water is disposed of because when you see the results of constantly freezing and unfreezing cheap water, you will wonder why you would ever drink it in the first place. Suspicious looking precipitants may appear in the water. If the top remains sealed, you have nothing to worry about.

Day Before Harvest

Clean and sanitize everything the day before harvest and keep a spray bottle of prepared StarSan to use on harvest day. I make 2.5 gallons of StarSan solution in a food grade bucket and keep it at 60 degrees. Heat will degrade all liquid chemicals. Remember, you are making food, so keep everything sanitized. Lay out a tarp to act as a “crush pad” surface and do not allow any unclean footwear on it. If you cannot secure the crush pad area from various critters (including humans), do this step on harvest day.

Harvest Day

Keep the grapes as cool as possible by covering them with pop-up tents, etc. while pressing the juice. Keep an adequate sample size (or a large cluster) for a harvest panel analysis by your favorite lab to test for adequate YAN levels and whether any acid or DAP additions are necessary before fermentation is started. Personally, my preferred lab is Lodi Wine Labs and they accept properly packaged samples from all over the U.S.

Make sure everything is sanitized again before use. Yes, I know it was done the day before.

Whole cluster press the white grapes to minimize skin contact time (my style choice and preferred flavor profile). Not all grapes will be pressed and there will be loss. A maximum of three pressings may be possible, but press fractions after the first pressing should be isolated until after fermentation is complete and organoleptic evaluation can be made comparing the different fractions. I only use the first pressed juice fraction to make my wine. And, yes, there is a considerable waste factor and unpressed whole berries on the crush pad. If that bothers you, then destem the grapes before pressing the berries. This approach will change the flavor profile of the wine.

Accumulate juice in your preferred container (i.e. stainless tank or “pickle barrel”). Add the 1st frozen gallon of water when about 10 gallons, or less, of juice has been pressed. You want to keep your wine below 40 degrees Fahrenheit if at all possible. This temperature will protect and stabilize the juice, so no KMBS is necessary. In fact, KMBS will inhibit yeast growth if you add too much. Not even “native” yeast grows in 40 degree temperatures unless maybe you live in Concord Grape country (not Concord, CA). Remember that everything is at risk until the yeast starts growing and produces CO2 that settles on top of the wine.

The juice will start becoming brownish due to oxidation, but that is okay for the first 36-48 hours. Personally, I think the oxidation adds to the quality of the wine. Try it with a Viognier and you will be amazed at the distinct floral and perfume aromas even though the juice is at 40 degrees.

Time to Add Yeast

Before you add yeast to start fermentation, rack your juice off the gross lees that have accumulated in the bottom of the container since pressing the previous day. This is a style choice that I prefer and does change the wine’s mouthfeel. If you choose to leave the juice on the gross lees, that is your style choice and you will be stirring the juice with all those gross lees as the yeast does its job of making alcohol.

Assuming it is time to add yeast, make sure the juice in your containers is brought up to the temperature the yeast needs to survive and grow. Follow the directions of the manufacturer when reconstituting the yeast for addition to the juice with a focus on the maximum temperature differential the yeast can tolerate between the juice and the warm water in which you have the yeast starting to grow. Use tap water if you have NO fluorine or chlorine added. The minerals give the yeast more surface area on which to grow. Otherwise use distilled water if you must when starting your yeast culture.

Primary Fermentation

Maintain the proper juice temperature the yeast needs to grow. Keep in mind that the temperature will rapidly increase following the lag phase of yeast growth. This is usually at about the 24 hour point after adding the yeast to your juice. The CO2 produced by the yeast will form a protective layer on top of the juice and protect the wine so KMBS is still not necessary. I am a firm believer in keeping the fermentation as slow as possible (7 days or more). Monitor the juice temperature and brix 2 times per day at a minimum when you also stir up the yeast to get more oxygen in the juice. Lower juice temperature means slower fermentation. You should observe/record high decreases in brix during the first 2 days of growth. Use those ice jugs to keep the temperature down, but not below the temperature the yeast needs to grow well and complete the primary fermentation. Thoroughly clean the jugs when you remove them from the juice and make sure they are sprayed with sanitizer before putting them into the wine each time you remove them from the freezer. DO NOT use any water bottle that appears compromised.

Adding Oak

Wood has Oxygen in it, so adding Oak at the beginning of primary fermentation (my preference) will make the yeast happy. You will need to make sure the yeast that accumulates on the staves is stirred back into the juice, so get a big 30” stainless spoon if you don’t have one yet. If you choose to add Oak after the completion of fermentation, soak the oak in water overnight to get some of the oxygen out of it.

Oak flavors will typically be fully extracted at 6 weeks. I use ½ of the total suggested by the manufacturer and keep it in for the full period. You can always add more oak, but it takes a year or more for the oak to diminish in your finished wine if you add too much Oak.

My Oak preference is medium toast French Oak mini-staves made by StaVin. I am willing to spend more to make award-winning wine.

There is a lot more to know about Oak, so I am working on a blog post focused on that aspect of winemaking.

Is Primary Fermentation Finished?

The brix reading should be lower that “0” on your hydrometer. Specific gravity isn’t the easiest topic to explain without getting into serious physics, so trust me (or check the internet for someone else’s “opinion”). Buy a good hydrometer for about $40 and don’t drop it. Use a 250mL (or larger) graduated cylinder to protect it when outside its box. You should have been monitoring/logging the brix and temperature at least twice a day, so you will see a stabilization in temperature when the yeast have stopped making alcohol. If brix is below zero and the temperature has stopped changing, it is time to add KMBS. Since there is no more CO2 being produced by the yeast to act as a protective layer on top of your wine, you must add an appropriate amount of KMBS for the wine’s pH. This step will also clarify brown, oxidized juice if you have chosen that approach.

Secondary Fermentation – Adding ML Bacteria

I never add ML bacteria to my white wine. But if you like the taste of movie theater popcorn butter in your wine, then adding Malolactic bacteria is the next step. You can normally add the ML bacteria before primary fermentation is finished. That’s what I do when making red wine. Yeast and bacteria don’t typically compete for the same nutrient sources.

Transfering Your Wine

After all fermentation is finished, keep your wine very cold with the ice jugs. I have a barrel room kept at 60° F, so it is easier for me to keep the wine cold using the gallon jugs. You will need to rack your wine off the “peanut butter” lees (dead yeast) that coats the bottom of your fermentation containers and then you can stop using the ice jugs.

Be aware that you will often “wake up” yeast when racking and CO2 will be produced as a result, so make sure you have an airlock or venting bung on your containers. Look at your wine a few days later to make sure your racking efforts have resulted in very clean wine. If so, then it’s time to wait and add KMBS as necessary for the next 3-5 months before bottling. I bottle white wine in Jan/Feb of the following year after harvest.

Wine Stability

Before bottling, you will need to make sure your wine is heat (protein) stabile using Bentonite as needed and after that you can make your wine cold stabile to keep acid from precipitating out. There will be a seperate post on wine stability in the future. Your wine is fine as for right now, but needs to be stabilized before bottling in a few months.

Closing Comments

Hopefully this will help you make white wine for the first time, or maybe a bit better than you have been doing. Please feel free to comment or send me an email. The purpose of this blog section is to help winemakers at all levels. I have tried to not take anything for granted in this post, so it is a bit longer than some people would want. It is important to note that I rarely work with less than 1000# at a time, so my techniques are based on that volume and learned from a world-class commercial winemaker.