Stopping fermentation of fruit wines

[DanielB]

Hi, I am new to this brewing malarkey, but thoroughly enjoying the learning process...

I have/had been fermenting to dry, but was advised that, if I can catch the ferment at a point I like, I could stop the process and then not have to back sweeten.

So, I have had some blackberry wine go from SG 1100 to 1010 and I liked the taste at this point, what do i need to do to stop the fermentation? It is only one demijohn worth (5L).

Should I add a campden tablet?
Should I add potassium sorbate?

What does each actually "do" - to help me understand the answer above :)

When I add the 'fermentation stopper', how quickly should I find my bubbler stops? Immediately? 24hrs?

Again, depending on the above, if it takes 24hrs to 'stop' I assume I should add it earlier so it actually finishes at my desired SG?

(Out of interest...to my first batch of BB wine, I ended up adding two campden tablets (as I thought this would stop the fermentation)...but a week later there's still a bubble every 30 seconds...)

Many thanks!!

 

[Dutto]

To "stop" fermentation it is normal to use a Stabiliser like this one from Wilco ...

https://www.wilko.com/en-uk/wilko-wine-stabiliser-30g/p/0022657

I used the Wilco Stabiliser on a cider.

No. 1 son likes sweet cider (I don't) so I let most of the Apple Juice ferment out, added the Stabiliser and then added more Apple Juice to sweeten it. It tasted fine to No.1 son but he didn't manage to drink it all on his visit.

The Stabiliser definitely worked because I needed the PB, moved the remaining cider to an FV, added an 11g packet of dried yeast and stuck it in the Brew Fridge to ferment out.

It sat in the Brew Fridge for about a week with no sign of life before I gave up and threw it away!

 

[ScottE75]

...but a week later there's still a bubble every 30 seconds...

Could just be residual CO2 coming out off the wine. That said, it is difficult to completely kill off the yeast, campden tabs stops acts as a preservative killing off bad bacteria, and Potassium sorbate stops the yeast from reproducing and is also used as a preservative in food and drink.

 

[Chippy_Tea]

Should I add potassium sorbate?

What does each actually "do" - to help me understand the answer above :)

I tried to stop fermentation early when i first started making wine as i liked it a little on the sweet side i quickly found its better to let it ferment to dry then add sugar to the bottle just before drinking as the last thing you need is the wine fermenting in your bottles.





Potassium Sorbate is another home wine making ingredient that many winemakers consider when trying to stop a wine from fermenting any further. There is a lot of misunderstanding surrounding this product.

It is typically called for by home wine making books when sweetening a wine. This is a situation where the fermentation has already completed and is ready for bottling. You simply add the Potassium Sorbate along with the sugar that is added for sweetening.

The Potassium Sorbate stops the wine yeast from fermenting the newly added sugar. So, many winemakers assume Potassium Sorbate can stop an active fermentation as well. But, nothing could be further from the truth.

Potassium Sorbate does not kill the yeast at all, but rather it makes the wine yeast sterile. In other words, it impairs the wine yeast's ability to reproduce itself. But, it does not hinder the wine yeast's ability to ferment sugar into alcohol.

Potassium Sorbate puts a coating on the cell wall of each individual wine yeast in such a way that budding or multiplying is next to impossible.

The idea here is that if you happen to have few cells of live wine yeast remaining in your finished wine, they will be rendered harmless if they are unable to regenerate themselves to great enough numbers to invigorate a fermentation of any kind. This is true even if more sugar is added to the finished wine.

Read in full - http://eckraus.com/wine-making-stop-fermentation/

 

[Chippy_Tea]

There is a recent back sweetening thread here - https://www.thehomebrewforum.co.uk/threads/sweeten-cider-after-fermentation.78683/#post-777697

 

[DanielB]

Chippy_tea, thank you for pointing me in this really useful direction, much appreciated!

I will look at the threads you recommend...

Would it seem though, that the wisest course of action is to, once dry, rack off.

• Add potassium Sorbate to inactivate yeast.
• Add a campden tablet (1 per d/j) to destroy any remaining yeast,
• and then back sweeten...?

 

[Chippy_Tea]

I think the easiest way to backsweeten is to use a non fermentable sweetener.

 

[DanielB]

Thank you.

With all my wines, now they have stopped bubbling in the demijohns - having already been fermented off the pulp, should I rack them again now, or just leave to mature be djs?

If I do rack now finished, should I add a campden tablet,?

I have peach, strawberry, rhubarb and blackberry all finished.