My Wine's Not Clearing With Finings.
There could be a couple of reasons why a wine will not clear when using finings, so let's explore the possible reasons and give you some remedies to each possible reason.
The Wine Is Still Fermenting
The first and most obvious reason is that the wine is still fermenting. The yeast are still active and no matter how much finings you add, as the fermentation is still going on, it will remain cloudy. The yeast are still munching compounds in the wine and can create CO2 (Carbon Dioxide) which can stop the wine from clearing. Use a hydrometer and check the specific gravity. If it is over 1.000, it is likely still fermenting.
The next reason a wine may not clear is due to a second type of fermentation called a malolactic fermentation. This can occur in fruit wines and is what creates that buttery flavour. This is a bacteria that eats malic acid and converts it into lactic acid. It also releases CO2 (Carbon Dioxide) and this can hinder the clearing process. Use a hydrometer and check the specific gravity. If it is over 0.996, it is likely still fermenting.
Even though a wine may have finished fermenting and both processes above have finished, there can be CO2 (Carbon Dioxide) dissolved in the wine. Just like bubbles in a can of coke, carbon dioxide is part of the wine and will gradually bubble out of suspension. This will prevent your wine from clearing.
Over time, CO2 will naturally evaporate from your wine, but you can speed this up in a process called degassing.
This is simply stirring the wine and so knocking out the CO2 from the liquid. This can usually take a couple of days for all the carbon dioxide to be expelled.
You can speed this process up using a wine whip, but remember, whip gently to knock the carbon dioxide out and not introduce air.
NB. When degassing, it is important not to introduce air into your wine as this can introduce the vinegar bacteria which can cause your wine to turn to vinegar. So degassing should be carried out gently.
Too Much Finings
Using too much wine finings can not only clear the wine, but can also strip flavours and mouth-feel. No matter what finings you are using, only use the directed amount for the quantity of wine you are making.
Finings work by attraction. Positively charged particles are floating around in your wine causing it to be murky. Finings are negatively charged particles and these attract the positively charged particles in the wine. They stick together and become too heavy to float in the wine and sink to the bottom.
So how can you use too much?
With some of the 2 stage fining methods, you first use a negatively charged finings which grabs all the positively charged particles in the wine. That can leave many negatively charged finings particles and these will grab on to other compounds in the wine and cause these to be removed too. That would affect the flavour, acidity and mouth feel of the wine.
So once the negatively charged finings particles have done their job, (usually between 1 – 24 hours) we want to eradicate any remaining negatively charged finings.
To do this, we introduce more positively charged particles, but just enough to mop up any left over negatives.
This is where we can add too much. If there were lots of particles in the wine to start with, they can use up all the negative finings. You will see you wine is almost perfectly clear. If you then add the next sachet, you are introducing too much positive finings and this can cause your wine to become milky.
For example, one of the most common finings in wine kits are Kieselsol (negatively charged) and Chitosan (positively charged). If this happens, you can then add a small amount of the first finings and your wine will clear again, but this can take time, so be patient. It will clear.
Pectin is a part of the cells that make up fruit. If pectin is allowed to be present in a finished wine, it will cause it to be hazy. There are various ways to remove pectin, but the 2 popular ways are pectic enzyme and bentonite.
Bentonite is a volcanic clay that soaks up the pectin.
Pectic enzyme (pectolase / pectinase) breaks down the cell walls, this also has a secondary benefit of helping to extract colour and juice from the cells.
Both Pectic Enzyme and Bentonite are normally used at the beginning of the fermentation process.
Some fruits have a lot more pectin than others, so you may find that pectin has managed to get through to the final stage.
If you believe you have a pectin haze, you can use a pectin test kit to be sure it is a pectin haze.
If it is a pectin haze, you can then remove a small glass of the wine. Add 1 tsp of pectolase to the glass of wine and leave for 10 minutes to hydrate. Add this back to your wine and stir to mix it all in.
Put in a warm place 18-22°C and leave to clear. You may find it can take up to 1 month for this to clear.
We are dealing with a living organism and sometimes they can be unpredictable. So remember to use a hydrometer to check the stages of your fermentation before you move onto the next stage.
Sometimes, it's just a matter of being patient and waiting. It will eventually clear.
Put your wine somewhere cool, where it will not be disturbed and leave it. If you have an airlock fitted, check every now and then to make sure it has some sterilising solution in the airlock to prevent an unwanted infection.
There is also nothing stopping you from drinking a hazy cloudy wine, it may just not taste as good as if it were clear though.
We would also recommend you filter your wine. Finings are great at getting most of the suspended particulates to drop to the bottom, but there are some microscopic sediments still suspended.
Using a filter like the Harris Wine Filter with catch those remaining particles and help improve the flavour and mouthfeel. The invisible particles reduce a wines zing, so removing them will really make a wine fit for a king.