It's gone cloudy and fizzy again??

[FeiX]

Hi everyone,

First time poster, I've been making cider from carton apple juice for a year. To 'celebrate' I decided to have a play with blueberry cider.

Carton apple juice, no additives.
Frozen store bought blueberries, defrosted and added into primary.
Bulldog cider yeast.
Bit of extra sugar.
Mug of strong tea.
Pectinaise and yeast nutrient - first time with nutrient.
My goal was to get a starting point of a sweet blueberry cider without having to back sweeten.

It fermented fine, I pull the berries out and got to around 6.5%, perfect for me - maybe abit too sweet and had a hint of blueberry. It cleared beautifully and had a beautiful colour but I decided to leave it to see if the blueberry flavour would develop over abit of time.

Ive checked it a couple of days ago and the colour has drained away from a lovely vibrant purple to slightly darker than apple cider, it's cloudy again and whilst it tastes fine (not developed like I hoped it would but still ok) it has that 'end of fermentation' fizz again.

We've put the heating on but it doesn't coincide with the changes.

Has it just started up again? Is it turning to vinegar? Any ideas?

Cheers!

 

[Chalkyt]

For me, the "maybe a bit too sweet" might be a bit of a clue. If there was some sweetness when you took the blueberries out, it suggests that the cider hadn't fully fermented.

Just throwing some numbers together... If you started with bought juice of SG1.045 or 1.050 plus a bit of extra sugar, your 6.5% ABV suggests around 50 gravity points of fermentation had happened, possibly leaving something like 5 to 10 gravity points left to go at that point. This could represent 10 to 20 grams of sugar per litre yet to be fermented. i.e. at least 1/2 teaspoon or more per 250ml glass or 12 oz bottle. Does that sound about right?

Without anything (i.e. heat or chemical pasteurising) to stop further fermentation, the yeast would just keep on gobbling up the remaining sugar to create fizz and an increasingly dry cider with an "unsweet" blueberry flavour component.

There is a chance that there could have been some residual sweetness from sorbitol (a non-fermentable sweetener found in some fruits) but this is unlikely since I understand that blueberries are low in sorbitol.

Anyhow that is my take on it. If you want the sweetness back (and this might enhance the blueberry flavour) you need to add sugar and pasteurise to stop fermentation or add a non-fermentable sweetener. There is plenty of information on both topics scattered around the forum, just use the search function up on the top RHS.

Good luck (and Merry Xmas)!

 

[FeiX]

For me, the "maybe a bit too sweet" might be a bit of a clue. If there was some sweetness when you took the blueberries out, it suggests that the cider hadn't fully fermented.

Just throwing some numbers together... If you started with bought juice of SG1.045 or 1.050 plus a bit of extra sugar, your 6.5% ABV suggests around 50 gravity points of fermentation had happened, possibly leaving something like 5 to 10 gravity points left to go at that point. This could represent 10 to 20 grams of sugar per litre yet to be fermented. i.e. at least 1/2 teaspoon or more per 250ml glass or 12 oz bottle. Does that sound about right?

Without anything (i.e. heat or chemical pasteurising) to stop further fermentation, the yeast would just keep on gobbling up the remaining sugar to create fizz and an increasingly dry cider with an "unsweet" blueberry flavour component.

There is a chance that there could have been some residual sweetness from sorbitol (a non-fermentable sweetener found in some fruits) but this is unlikely since I understand that blueberries are low in sorbitol.

Anyhow that is my take on it. If you want the sweetness back (and this might enhance the blueberry flavour) you need to add sugar and pasteurise to stop fermentation or add a non-fermentable sweetener. There is plenty of information on both topics scattered around the forum, just use the search function up on the top RHS.

Good luck (and Merry Xmas)!

Thanks for the response!

So you think that when the cider was at its best re:clarity and colour, it had actually sort of stalled?

And now it's started up again, do you think I'd be able to get the colour and clarity back?

I've not pasteurised or used Camden tablets in any of my brews before, relying on the yeast to have reached it's alcohol tolerance instead but I will have a search.

Thanks!

 

[Chalkyt]

I don't think it stalled as such. That happens when the yeast stops working because the cider has run out of the nutrients that the yeast needs to do their work. This most commonly happens with high nutrient demand ale yeasts (particularly S04 and the like) and juice from old, over-ripe apples from unfertilised trees which I wouldn't think is your situation since you added nutrient.

I am not familiar with Bulldog yeast so I did a bit of Dr Google research. It appears that the yeast packets have acesulfane added. This is a non-fermentable sweetener and may explain the initial sweetness. Some artificial sweeteners can give cider a "strange" taste and I really don't know what effect they might have on SG or anything else. Did you measure the SG at the end?

The loss of colour and clarity is a bit of a mystery. What was the heating that you put on? Normally towards the end of fermentation, expired yeast and pulp will settle out leaving a clear cider, and in your case the carton juice should have been clear with no sediment to start with, and I didn't find any indication the buldog has any other additives that might explain what has happened. The tea would add a bit of tannin and colour but I can't think of any reason for this to be an issue. Others might have some ideas.

 

[FeiX]

Im assuming the haze is from the blueberries in primary.
The heating was just the household heating, the under stairs cupboard I use for brewing has a hot pipe through it but we don't have the heating on particularly high.

I might try racking it off and leaving it another couple of weeks to see what happens. It's about that time that i'd be sticking a new brew in anyway - I'll drop the extra sugar this time. Thankfully I'm only doing small batches til I can get this recipe down.

Thanks for all the info, Merry Christmas!