How to Make Wine Without Yeast

Strictly speaking, you cannot make wine without yeast: yeast is what turns the sugar in fruit into alcohol and carbon dioxide. What you can do is make wine without adding yeast, by letting the wild yeast that lives on fresh fruit do the work. That is how all wine was made for thousands of years, and some wineries still do it today. This guide explains how to make wine without yeast from a packet, step by step, and how to stack the odds in your favor.

Do You Have to Use Yeast to Make Wine?

You have to have yeast; you do not have to buy it. WineMaker magazine’s Jeff Chorniak, in Wild Yeast: The Pros and Cons of Spontaneous Fermentation, puts it plainly: one thing never changes, you need yeast to make wine. Yeast gets into the must in one of two ways. Either you inoculate it with a cultured strain from a packet, or the wild yeast already on the fruit, in the air and on your equipment takes hold by itself.

He also points out that cultured yeasts have only been part of winemaking within the last century. Before that, every wine was fermented by wild, indigenous yeast. Inoculating is a choice, not a requirement, which is why the real question is not whether you can skip the packet but whether you want to accept the risk that comes with it.

Can Grape Juice Turn into Wine Without Yeast?

Bottled grape juice from the supermarket almost never will. The US Food and Drug Administration notes that most of the juice sold in the United States is pasteurized, a heat treatment applied to kill harmful bacteria. That juice was pressed from washed fruit and then heated, so it is not a reliable source of the wild yeast that lives on grape skins. Left open, it is more likely to go moldy or sour than to turn into wine. Wine kit concentrates are the same: WineMaker notes that kit wines will not ferment at all unless you add yeast, because the processing removes or kills every living organism in the concentrate.

Fresh juice pressed from unwashed grapes is different: it still carries the yeasts from the skins, and it can ferment spontaneously. WineMaker describes juice buyers being told to take it home and let it sit until it starts on its own, which it often does within a day or so. If you want to make wine from bottled juice, add a wine yeast and follow our guide to making wine from grape juice.

What Is Wild Yeast?

Wild yeast is the yeast that occurs naturally on fruit and plants, in the air and on every surface of a vineyard or a kitchen, as opposed to a strain that has been isolated, grown and dried into a packet. Any species can end up in your must, good for wine or not, and the mix varies from one place to another.

Wine Yeasts and Spoilage Yeasts

Thousands of wild yeasts exist, and for winemaking WineMaker divides them into two groups: wine yeasts and spoilage yeasts. The species that does most of the work in almost every wine, Saccharomyces cerevisiae, is surprisingly rare outdoors. The article cites studies suggesting it is found on only about one berry in 1,000, and in some vineyards on none at all. Other indigenous yeasts can also make wine, but they behave differently.

Feral Yeast

There is a third, in-between category. WineMaker uses the term feral yeast for yeast that lives in a winery itself, on equipment, in the wood of barrels and on people’s hands and clothes. It may be escaped cultured yeast, blown-in wild yeast or a mix. If you have made wine in the same kitchen before, some of it will be in yours.

What Actually Happens in a Wild Fermentation

A spontaneous fermentation is not one yeast but a relay. Researchers who tracked a Swiss winery’s wild ferments (Díaz and colleagues, BioMed Research International, 2013) found several non-Saccharomyces species active in the must, including Metschnikowia pulcherrima and Pichia species, alongside Saccharomyces cerevisiae. The same study found so-called spoilage yeasts in every fermentation, yet high levels of acetic acid, the vinegar note, built up only in the batches with an extended lag phase.

The Relay, Stage by Stage

WineMaker calls the good version of this a sequential fermentation. The wild yeasts start first, and often shut down at 3 or 4% alcohol. Meanwhile any Saccharomyces cerevisiae in the must multiplies, and within 3 or 4 days it can dominate, finishing the fermentation to dryness and a higher alcohol as the wild yeasts die off. The result, when it works, is a wine with complex flavors and aromas and normal strength.

Why the Lag Phase Is the Danger

Wild yeast starts in much smaller numbers than a packet delivers, so it takes longer to get going: up to a week in larger batches, according to WineMaker. During that wait, bacteria such as Acetobacter and Lactobacillus can grow and produce volatile acidity, the sharp vinegar smell. That is the practical lesson for home winemakers: anything that shortens the lag (ripe, sound fruit, warmth, a clean vessel, a starter) lowers the risk.

Why Wild Ferments Get Stuck

If there is little or no Saccharomyces cerevisiae in the must, nothing takes over. WineMaker notes that many wild yeasts cannot perform once alcohol reaches about 6%, which leaves a stuck fermentation, a weak, flabby wine and a lot of unwanted residual sugar. Our page on stuck fermentation covers the rescue.

How to Make Wine Without Added Yeast, Step by Step

Grapes are the most reliable fruit for a wild ferment: they carry their own yeast, need no water, and have the sugar and acid to protect themselves. The card below is the old-fashioned way to make grape wine, written for one gallon. The same method works for other fruit; see the notes further down.

Recipe card

Wild-fermented grape wine, 1 US gallon

Makes

About 5 bottles (750 ml)

Time to drink

4 to 8 months

Difficulty

Intermediate

Ingredients

• 14 to 16 lb ripe wine grapes, picked dry, not washed
• No Campden tablets before fermentation
• No added yeast (keep 1 packet of wine yeast in reserve)
• Sugar only if the juice reads below 1.090
• 1 tsp yeast nutrient, optional

Method

1. Discard moldy or damaged bunches. Crush the grapes into a sanitized bucket, leaving plenty of headspace.
2. Squeeze out a cup of juice, read its gravity and write it down. Add the nutrient if you use it.
3. Cover with a clean cloth and keep the bucket near 70 °F. Stir and push down the skins two or three times a day.
4. Watch for foam, fizzing and a falling gravity. If there is no sign of fermentation after several days, add the reserve yeast.
5. Read the gravity daily. Once it has fallen by about 0.025 to 0.030, roughly 3 to 4% alcohol, you can add the wine yeast as insurance.
6. After about five days of active fermentation, press the grapes into a 1 gallon jug and fit an airlock. Add any missing sugar once it calms down.
7. When fermentation is complete, rack off the sediment, top up, add a Campden tablet and age 3 to 6 months before bottling.

Method adapted from Jack Keller’s Simple Grape Wine (Requested Recipes Collection, 2020) with its Campden tablets and yeast left out, and from the spontaneous fermentation guidance in WineMaker magazine’s Wild Yeast: The Pros and Cons of Spontaneous Fermentation.

Step 1: Pick the Right Fruit on the Right Day

The yeast you need is on the skins, so do not wash it off. Pick ripe, sound fruit on a dry day. WineMaker warns that rain just before harvest can wash yeast off the grapes, leaving the population severely reduced, while the moisture encourages rot. If you buy grapes, ask whether they have been sulfited: some vineyards crush the grapes and add sulfur to stop exactly the spontaneous fermentation you want.

Step 2: Crush, Measure and Cover

Crush the fruit into a sanitized bucket and take a hydrometer reading straight away, because the gravity is the only way to know whether anything is happening. Skip the Campden tablet: sulfite is added to musts precisely to stun or kill wild yeast. Cover the bucket with a cloth rather than a sealed lid, so carbon dioxide can escape and fruit flies cannot get in.

Step 3: Keep It Warm and Stir

Virginia Tech keeps red wine musts at about 70 °F during primary fermentation; avoid a cold room, where a slow wild start gets slower still. Stir two or three times a day and push the cap of skins back under the juice; Keller does the same with inoculated grapes.

Step 4: Decide When to Step In

WineMaker describes what experienced winemakers do: they let the spontaneous fermentation begin, take regular gravity readings, and when they estimate the alcohol has reached 3 or 4%, they sometimes inoculate with Saccharomyces cerevisiae to make sure it finishes. You keep the complexity of the wild start and gain a sound finish. Our ABV calculator turns gravity readings into alcohol.

Step 5: Press, Finish and Protect

Press the grapes after about five days, as Keller does, and finish the wine in a jug under an airlock. Once fermentation is over, the case against sulfite disappears: rack the wine off its sediment, top up and add a Campden tablet to protect it while it ages. From here it is ordinary winemaking; see how to rack wine and how to bottle and cork wine.

How to Improve Your Odds With Wild Yeast

Wineries that rely on wild yeast rarely leave it entirely to chance. These are the techniques WineMaker describes, scaled down to a kitchen.

Pied de Cuve: A Wild Yeast Starter

Some wineries pick a small portion of their grapes about a week before the main harvest. If the fruit is still acidic, they add a little water, then stir and aerate it to wake the wild yeast. After several days it is fermenting vigorously, and they use it as a starter for the main batch. At home, crush a pound or two of the same ripe fruit in a sanitized jar a few days ahead, cover it with a cloth, stir it daily, and pour it into the main must once it is bubbling hard. The French name, pied de cuve, means roughly the foot of the vat.

Blending Wild and Cultured

Split the fruit into two batches, inoculate one with wine yeast and let the other ferment spontaneously, then blend them when both are finished. If the wild half goes wrong, you still have a good wine. WineMaker notes that many California wineries blend wild-fermented and cultured wine this way with good results.

Feed the Yeast

Wild yeast starts from a smaller population, so a must short of nutrients can stall more easily. WineMaker suggests building up nutrients with diammonium phosphate (DAP); check the label of your yeast nutrient to see what it contains. The Australian Wine Research Institute adds that yeast under stress, for example running out of nitrogen, produces hydrogen sulfide, the rotten egg smell.

What Makes a Wild Ferment Succeed or Fail

You cannot know which yeasts are in your must without a laboratory, but the condition of the fruit tells you a lot about the odds.

Acidity and pH

Fruit picked with good acid and a low pH resists spoilage during the lag phase, which is when the must is most exposed. WineMaker makes the point for grapes; the same logic suggests that tart fruit such as sour cherries is a safer bet than sweet, low-acid fruit.

Rain Before Harvest

Rain washes yeast off the fruit and encourages rot. If you must pick after rain, plan to inoculate at 3 or 4% alcohol, or from the start.

Sulfur on Bought Grapes

WineMaker notes that crushed grapes sold to home winemakers are often treated with 30 to 50 ppm of sulfur dioxide to stun or kill wild yeasts. Grapes like that will not ferment spontaneously; ask before you buy.

Nutrients

Fruit low in nitrogen gives the small wild population less to work with. A teaspoon of yeast nutrient per gallon is simple insurance.

Local Yeast and History

The famous wild-fermented wines of the Old World come from places that have been making wine in the same spot for generations. WineMaker explains that decades of fermenting the same grapes and returning pomace and yeast sediment to the vineyard build up a dominant population of a few strains, on the vines, the winery walls, the equipment and the barrels. Every harvest then ferments with the same native yeast. A new home winemaker does not have that advantage, which is one more reason to keep a packet of yeast in reserve.

Wild vs Cultured Yeast at a Glance

Figures from WineMaker’s wild yeast article. For cultured strains matched to each fruit, see our best wine yeasts guide.

Signs a Wild Ferment Is Working, or Going Wrong

Good Signs

Foam and fizzing on the surface, a cap of skins that keeps rising, a smell that moves from fresh fruit to yeasty and winey, and above all a gravity reading that falls from one day to the next.

Warning Signs

• A sharp vinegar or nail-polish smell: volatile acidity, often with ethyl acetate, the main risk of a long lag. The Australian Wine Research Institute notes that the ethyl acetate aroma can sometimes dominate. Act at once: add wine yeast to get a vigorous fermentation going.
• A rotten egg smell: hydrogen sulfide from stressed, hungry yeast. Stir in yeast nutrient.
• A white, wrinkled film on the surface: film yeasts, which Purdue University’s enology extension describes as surface biofilms of several wild yeasts. They grow where wine meets air; see wine faults for what to do.
• No change in gravity after several days: the wild yeast has not taken hold. Add wine yeast rather than waiting.

Fruit Wine Without Yeast: Blackberry, Plum and Cherry

The same rules apply to any fruit: use ripe, sound, unsprayed fruit, do not wash off the skins more than you must, skip the Campden tablets, crush it, cover the bucket with a cloth and stir daily. Most fruit other than grapes needs water and sugar added, which dilutes the wild yeast, so measure the gravity at the start to know whether anything is happening. The amounts for each fruit are in our fruit wine guide.

Blackberry Wine Without Yeast

Wild blackberries picked dry and used the same day are the best candidates, since the berries go straight from bramble to bucket. Crush them, add the sugar and water your recipe calls for, and watch for foam and a sour-fruity smell turning yeasty within a few days. If nothing happens, add wine yeast rather than waiting longer. Our blackberry wine recipe gives the quantities.

Plum Wine Without Yeast

Plums ferment readily once crushed, but the stones and the high pectin make the must thick. Pit the fruit without cracking the stones, crush the flesh and skins, and strain carefully before moving the wine into a jug. Plum wines often stay hazy without a pectic enzyme, which you can add once fermentation is underway. See our plum wine recipe.

Cherry Wine Without Yeast

Sour cherries bring plenty of acid, which protects the must while wild yeast gets going. Pit them, or at least avoid crushing the stones, and keep the skins in for color during the first days. Sweet cherries have less acid and more risk of spoilage during a slow start.

Can You Make Alcohol Without Yeast?

Almost every fermented drink relies on yeast. The one notable exception is a bacterium, Zymomonas mobilis, which ferments sugar to ethanol and carbon dioxide much as yeast does. It was first isolated from drinks such as African palm wine and Mexican pulque and is traditionally used to make pulque. It is not something you can buy for home winemaking, and in cider and beer it is a spoilage organism, so in practice making alcohol at home means yeast, wild or cultured.

Rice Wine Without Yeast

Rice contains starch, not sugar, so yeast cannot ferment it until enzymes break the starch down. Traditional rice wines use a starter culture of molds and yeasts, which is a different process from fruit wine.

Honey Wine Without Yeast

Honey diluted with water can ferment from wild yeast, but it is slow and unreliable. Our guide to making mead covers the dependable method.

What helps a wild fermentation succeed

You do not need a starter kit for a wild ferment, but these three items make it far less of a gamble.

1. 

   1Hydrometer

   Brewer’s Elite Triple Scale Hydrometer and Test Jar

   The only way to know whether a wild ferment has started, stalled or finished.

   Check price on Amazon

2. 

   2Fermenting jug and airlock

   North Mountain Supply 1 Gallon Glass Fermenting Jug with Airlock

   Moves the wine off the fruit and under an airlock once it is fermenting, away from vinegar-making air.

   Check price on Amazon

3. 

   3Rescue yeast

   Lalvin EC-1118 Wine Yeast (10 pack)

   If the wild yeast never starts, or stalls with sugar left, a packet of wine yeast finishes the job.

   Check price on Amazon

Wine Without Yeast FAQ

Wild fermentation is not the lazy way to make wine, as WineMaker puts it; it takes more attention than adding yeast, not less. Start with sound fruit, keep a hydrometer handy and a packet of yeast in the drawer, and you get to taste what your own fruit and your own corner of the world can do. Make and drink wine responsibly, and only if you are of legal drinking age.