Few things are more frustrating for a home winemaker than spending time preparing a batch, pitching the yeast and then seeing absolutely nothing happen.
No bubbles.
No froth.
No signs of activity.
It's one of the most common questions we hear from beginners:
"I've started my wine but it doesn't seem to be fermenting. What have I done wrong?"
The good news is that a lack of visible activity doesn't always mean something is wrong.
In fact, many perfectly healthy fermentations cause unnecessary panic because home winemakers are looking for the wrong signs.
Before you throw away a batch or start adding extra ingredients, it's worth understanding how fermentation works and what can prevent yeast from doing its job.
In this guide we'll look at the most common reasons wine fails to start fermenting, how to diagnose the problem and the steps you can take to get your wine back on track.
How Do You Know If Wine Is Actually Not Fermenting?
The first thing to understand is that an airlock isn't always the best indicator of fermentation.
Many beginners assume that if the airlock isn't bubbling, fermentation hasn't started.
That's not necessarily true.
A loose lid, imperfect seal or small leak around a bung can allow carbon dioxide to escape without producing visible bubbles.
This is particularly common when using fermentation buckets.
Instead of relying solely on airlock activity, look for other signs of fermentation:
- A layer of foam forming on the surface
- Cloudiness developing in the wine
- Sediment beginning to appear
- A slight fizzing sound
- A falling specific gravity reading
The most reliable way to confirm fermentation is by taking hydrometer readings.
A hydrometer allows you to measure the specific gravity of your wine and determine whether sugar is being converted into alcohol.
If the gravity is falling, fermentation is happening regardless of what the airlock is doing.
Reason #1: The Temperature Is Too Low
Temperature is one of the most common causes of slow or stalled fermentation.
Wine yeast performs best within a specific temperature range, usually somewhere between 18°C and 24°C depending on the strain.
If the must becomes too cold, yeast activity can slow dramatically or stop altogether.
This often happens during colder evenings, in garages, sheds or rooms that experience large temperature fluctuations.
If your wine is sitting below the yeast's recommended range, try moving it to a warmer location and allow 24 to 48 hours to see whether activity resumes.
A brewing thermometer can help you monitor conditions more accurately.
Reason #2: The Yeast Hasn't Activated Properly
Sometimes the problem is simply the yeast itself.
Wine yeast can be affected by age, poor storage conditions or incorrect preparation.
If the yeast packet has been exposed to excessive heat, moisture or has been sitting in storage for a long period, viability may be reduced.
This is why many experienced winemakers keep a spare packet of wine yeast available when starting a batch.
If there are no signs of fermentation after several days and temperature isn't the issue, pitching fresh yeast may be necessary.
Reason #3: You've Added Too Much Campden Tablet
Campden tablets are extremely useful in wine making, but timing matters.
Many recipes use Campden tablets to suppress wild yeast and bacteria before fermentation begins.
However, if cultured wine yeast is added too soon afterwards, the sulphur dioxide can also affect the yeast you actually want to grow.
This is a surprisingly common mistake among beginners.
If you've recently treated your must with a Campden tablet, check the recipe instructions and ensure sufficient time has passed before pitching yeast.
In many cases, simply waiting a little longer before re-pitching fresh yeast can solve the problem.
Reason #4: The Wine Needs Yeast Nutrient
Yeast needs more than sugar to thrive.
It also requires nutrients to reproduce and carry out a healthy fermentation.
While grape juice naturally contains many of these nutrients, country wines and fruit wines can sometimes lack the nutrients yeast needs.
This is particularly common in recipes made from flowers, berries and other non-grape ingredients.
If the yeast struggles to establish itself, fermentation may start slowly or stop altogether.
Adding a suitable yeast nutrient can often help support a stronger and more reliable fermentation.
This is one reason you'll see yeast nutrient included in many recipes, including our elderflower wine recipe.
Reason #5: The Sugar Level Is Too High
It sounds strange, but too much sugar can sometimes prevent fermentation.
Many beginners assume that adding extra sugar will automatically produce more alcohol.
Unfortunately, excessive sugar concentrations can place significant stress on yeast.
When the starting gravity becomes too high, yeast may struggle to establish itself and fermentation can become sluggish or fail to start properly.
This is particularly common when people modify recipes or attempt to increase alcohol content without adjusting other ingredients.
If you suspect the sugar level is excessively high, taking a hydrometer reading is usually the best place to start.
Reason #6: You're Using the Wrong Yeast
Different yeasts are designed for different jobs.
A yeast that performs brilliantly in one recipe may struggle in another.
For example, some wine yeasts are selected for high alcohol tolerance, while others are chosen for preserving delicate fruit flavours.
Using an unsuitable yeast doesn't always prevent fermentation entirely, but it can contribute to poor performance.
When following a recipe, it's usually best to use the yeast strain recommended by the author or manufacturer.
Quality wine yeast is inexpensive, and using the correct strain can make a noticeable difference to the finished wine.
Reason #7: Fermentation Has Already Finished
This sounds obvious, but it catches people out all the time.
Some wine fermentations start very quickly and complete faster than expected.
By the time the winemaker checks on the batch, the most active phase of fermentation has already passed.
As a result, the airlock appears quiet and there's little visible activity.
The assumption is that fermentation never started.
In reality, it may already be complete.
This is another reason why hydrometer readings are so important.
A hydrometer can tell you whether sugar remains in the wine and whether fermentation is still progressing.
It removes the guesswork and provides a much more reliable picture than simply watching for bubbles.
How to Restart a Stuck Wine Fermentation
If you've identified the cause of the problem, don't panic.
Most stuck fermentations can be recovered.
Start by checking the temperature and ensuring it falls within the recommended range for your yeast.
Take a hydrometer reading to confirm whether fermentation has actually stalled.
If necessary, add yeast nutrient and consider pitching a fresh packet of wine yeast.
Try to avoid making multiple changes at once.
By addressing one potential cause at a time, you'll have a much better chance of identifying what was preventing fermentation in the first place.
Patience is often the most valuable ingredient in home winemaking. If you're just getting started, our Beginner Wine Making Starter Kit includes everything you need to brew with confidence from day one.
Frequently Asked Questions
How long should wine take to start fermenting?
Most wine fermentations begin within 12 to 48 hours of pitching the yeast.
Temperature, yeast strain and recipe all play a role, so some batches may take slightly longer than others.
If there are no signs of activity after two days, it's worth checking temperature, yeast health and hydrometer readings before taking further action.
Can I add more yeast if fermentation hasn't started?
Yes.
If you suspect the original yeast has failed, pitching a fresh packet of wine yeast is often the simplest solution.
Before doing so, make sure you've addressed any underlying issues such as temperature or excessive sulphite levels.
Otherwise, the new yeast may encounter the same problem.
Can a stuck fermentation be saved?
In many cases, yes.
Most stalled fermentations are caused by factors such as low temperature, nutrient deficiencies or stressed yeast.
Identifying and correcting the cause often allows fermentation to restart successfully.
This is why taking a methodical approach is usually better than immediately adding more ingredients.
Should I trust the airlock?
Not entirely.
An airlock can provide useful clues, but it should never be your only indicator of fermentation.
Small leaks around lids, bungs or bucket seals can allow carbon dioxide to escape without visible bubbling.
Hydrometer readings remain the most reliable way to confirm whether fermentation is taking place.
Can wine ferment without bubbling?
Absolutely.
Many healthy fermentations produce very little visible airlock activity.
That's why experienced winemakers rely on gravity readings rather than bubbles alone.
Do fruit wines ferment differently from grape wines?
They can.
Fruit wines and country wines often contain different nutrient levels and may benefit from yeast nutrient additions.
This is one reason recipes for elderflower wine and blackberry wine frequently include nutrient alongside the yeast.
Final Thoughts
If your wine doesn't appear to be fermenting, don't assume the batch is ruined.
Most fermentation problems can be traced back to a small number of common causes.
Temperature issues, poor yeast health, nutrient deficiencies and incorrect sulphite use account for the vast majority of stalled fermentations.
The key is diagnosing the problem properly before taking action.
Rather than relying solely on airlock bubbles, use a hydrometer to understand what's actually happening inside the fermenter.
A few simple checks can often save a batch and prevent unnecessary frustration.
Whether you're making elderflower wine, fruit wine, country wine or cider, good fermentation management is one of the most important skills a home winemaker can develop.
Need supplies for your next batch? Browse our range of Wine Yeast, Yeast Nutrient, Campden Tablets, Hydrometers and Wine Making Supplies to help keep your fermentation on track.