Lately, a whole lot of people have been asking me how to make wine without yeast. Well ladies and gentlemen, today we’re going to find out!
Simply put, it’s impossible to make wine without yeast. Be it wild or cultured, it’s the single most important part of winemaking as it’s what kickstarts fermentation (converting the sugars of wine grapes into alcohol and carbon dioxide), turning simple grape juice into wine in the first place.
Now, I’m willing to bet that most of you that ask this question actually want to know if it’s possible to make wine without cultured yeast – and the answer to that is yes, by using wild yeast instead. Let’s take a more in-depth look into this below.
Wild Yeast, as the name implies, is the sort of yeast culture that’s present in the wild instead of being cultured, identified, preserved and then used.
Wild yeast, when it comes to wine-making, lives mainly on the fruit you use and is also present on the elements and your instruments, tools and other surfaces as the wind spreads it all around. Its quantity and quality varies highly from place to place and depends on a number of factors as well, with one of the biggest being the type of area (farm, city, etc…).
As you can tell by now, it’s highly unpredictable due to the wide array of varying factors that make or break wild yeast. Although you can take measures to improve its reliability and monitor its progress (checking the wine’s odor, temperature, alcohol and so on), it’ll never be as safe of a bet as cultured yeast and that’s why many wine makers don’t use it.
Even then, wild yeast is beloved by many and even considered to be the true, natural representation of wine since it brings a level of complexity and character to the final product that’s unique and fully embodies the region that it’s from. Using foreign cultured yeast can take this strong personality away from your wine as it doesn’t use your locale’s unique strain of yeast.
There are many factors that affect the amount of wild yeast present in your area and the chances that it’s effective. These are the main ones:
Low PH and good acid in the grapes will inhibit spoilage which is crucial due to wild yeast’s lag phase. By having both of these qualities, you’ll protect your must during the time that it takes for the spontaneous fermentation to kick in.
If you use your own grapes, make sure to check these factors to get an idea of how resilient they are during the lag phase. If you buy them from someone, make sure to ask about this as most merchants will shock the grapes with sulfut to avoid spoilage and you must avoid sulfur if you want wild yeast.
If rain falls before you harvest, it can wash off yeast cell populations that were present in the grapes, leaves, equipment and so on. This will severely reduce the wild yeast count and negatively affect the possibilities of the spontaneous fermentation. That much moisture also promotes rot, another negative trait of rainfall before harvest.
Now, while rain is terrible and can wash off saccharomyces cerevisiae (baker’s yeast, which will take over the wine at a later stage and finish its fermentation) you can still give your wild wine making a try. If it starts fermenting, monitor it closely and if you notice that it gets stuck at a lower alcohol level such as 3 to 4%, you must inoculate with cultured yeast (or you risk the fermentation being halted due to lack of the stronger baker’s yeast).
In order for your yeast to colonize, reproduce and perform correctly, your must needs to be nutritious – even if you use cultured yeast. Although this isn’t a very common problem, you can build nutrients in the must, if needed, by adding diammonium phosphate (DAP) to it. This will ensure that your yeast prospers and gets strong enough to take the fermentation process to completion.
The reason behind old world wine’s massive success with wild yeast is their rich micro flora which is a direct result of their long wine making history. After decades upon decades of growing, fermenting and dumping the old pomace and yeast sludge back into the vineyard, an ever-increasing buildup of a few particular yeast strains will start to dominate the region.
As mentioned above, they’ll blow in the wind and stick to all kinds of surfaces, equipment, fruit, nature, wood barrels and even the hands and clothing of everyone there. In this case, the grapes will be covered with the same dominant micro-flora each and every year for years on end. After decades and even centuries of this practice, every grape harvest will spontaneously ferment with that unique, native strain or strains of yeast, cutting the need for foreign inoculation.
It’s a true wonder of the olden wine making regions such as Portugal, Italy, Spain and France, and it’s the major reason for some of these regions dismissing or even not knowing about adding yeast to their must – they’ve never needed it and won’t ever need it in the future.
These are the most relevant pros and cons of using wild yeast based not only on my own knowledge but also on winemaker’s mag article on it.
Now, it’s not necessary for you to have had generations upon generations of wine making happening around you to successfully make wine with wild yeast, but it’s what ensures effortless success.
Even then, there are a couple of techniques to help you achieve success with wild yeast, take a look:
These are the two most popular and successful techniques, used by wineries all around the world to try and get the best of both worlds – the complexity and character of wild yeast with the reliability and safety of cultured yeast.
Simply put, you inoculate wine with your very own wild yeast. You do this by picking a bunch of grapes before the main harvest and adding a bit of water to them if they’re acidic. Then, you stir and aerate that pre-harvest batch to stimulate the wild yeast and get it to ferment. Then, after the actual harvest is done, you simply add the already fermenting small wild yeast batch to the main one, inoculating it all and ensuring success.
This technique is called Pied de Cuve.
A popular security measure when aiming for spontaneous fermentation, blending is a solid compromise to better your chances of success.
You separate your harvested grapes into two batches and then proceed to inoculate one while allowing the other to spontaneously ferment. When they’re both fermenting, blend them to gain the complexity and unique character of the spontaneously fermented batch while still having the safety net of the inoculated one. This way, even if the wild batch goes wrong, you’ve still got a safe batch of great wine.
It’s a decent compromise that many California wineries practice, for example.
And there you have it – is it possible to make wine without yeast? Nope. Is it possible to make wine without cultured yeast? Absolutely.
Thanks to everyone that sent in this interesting question and I truly hope that I managed to clear all of your doubts and teach you a few valuable bits of information about the subject. See you on the next one!