Cider Acid level is Rising. Help!

[Wapiti Dreamer]

Hello all,

I'm new to cider making and could use some help. Any and all comments would be appreciated (I've got a thick skin).

After pitching yeast on December 7, I tested the acid level today (December 11). The acid level appears to have risen from approximately .7 to .9

Here's the history:

On December 6, I mixed five gallons of dessert apples from Northern California. The specific gravity was originally 1.06. The total acid was .6 The must lacked any taste of tannin (almost no pucker).

So ...., I added 4 teaspoons of acid blend to bring the acid level up. I also added suger (27.5 ounces) to bring up the specific gravity to 1.74. Finally, I added 1.5 teaspoons of tannin. I added Camden tablets and let sit for 24 hours. I also added 1.25 teaspoons of pectic enzyme for fining.

On December 7, I pitched 5 grams of EC-1118 sparking wine style yeast. I also added three teaspoons of yeast nutrient.

I placed the carboy in a cool dark spot for 2 days. A light kruassen formed, the must cleared, and a sediment layer formed at the bottom of the carboy. However, I was concerned that the area was too cold at about 54 degrees. So, on December 9, I moved the carboy to another location that is about 60 - 62 degrees. It sat for two days and became more active. The kruassen has grown to approximately one inch. The must is now cloudy and the fermentation lock is bubbling away. It has a nice apple aroma. The must has developed a fine champagne style bubble. The specific gravity has dropped to 1.53. But the acid has risen to .9 from .7.

The must tastes good. It does not taste like vinegar. Its still sweet with a nice bubble.

Should I be concerned at this early stage? Am I making vinegar? Any suggestions?

 

[PD]

does it smell of vinegar ?

sounds like its doing fine to me.I've never tested ph on a brew so can't say what it should be or what if any effect it will have.

 

[Wapiti Dreamer]

It doesn't have any smell of vinegar. Very aromatic smell of apples.

 

[PD]

quote.

Very aromatic smell of apples.

well that's good for a cider........

 

[evanvine]

I'm surprised that your acid level has risen from 7ppt to 9ppt during ferment.
1 tsp/4.5ltrs of precipitated chalk should reduce your acid by 1ppt.
Your ideal level is 5-6 ppt.

 

[Stanleythecat]

I'm surprised that your acid level has risen from 7ppt to 9ppt during ferment.
1 tsp/4.5ltrs of precipitated chalk should reduce your acid by 1ppt.
Your ideal level is 5-6 ppt.

Sorry to butt in but what is ppt and how do you measure it.

Leo

 

[evanvine]

Sorry to butt in but what is ppt and how do you measure it.

Ppt is parts per thousand as opposed to ppm which is parts per million.
It is measured by titration which is a whole post on its own.
Basically you use Sodium Hydroxide at a known strength to neutralise the acid.
The acid strength is calculated from the amount of NaOH used.

 

[tonyhibbett]

Such a dramatic rise in acidity is implausible. Most likely the sodium hydroxide used in titration has oxidised. Get a fresh solution.

 

[Ken L]

Personally I'd leave it closed, let it ferment out and give it a sniff/taste as you are ready to bottle it.
Constantly opening it is a very good way to get it infected.
I follow a broad recipe for my ciders but every one is subtly different with more or less acidic, more or less tannic flavours etc and that adds to the interest.

 

[Wapiti Dreamer]

Thanks for all the great input. Really appreciate the support.

Here's my status. I'm one week out from casting the yeast. The must is cloudy, but aromatic with a nice fine bubble consistent with a champagne style yeast.

I just checked the SG. It's at approximately 1.005 -- that's down from an original of 1.074. So I think that gives me an alcohol level of about 9% which is what I was looking for. Strong but within reason.

My air lock is still bubbling a bit, very calmly. I'm thinking I'll let it go for another week. Then I'd like to rack it and let it stand for some time in the hopes of getting an MLF to smooth and round out the character.

I'd love any thoughts or suggestions. I'm in no hurry. Ultimately I want to bottle in way that will give the cider some bubble.

Thanks all.

 

[jonewer]

How do you measure acidity in cider?

 

[Donny70]

I use Litmus paper which you can get in any brew shop. Unless someone can tell me of a more accurate electronic device I could buy myself for christmas???

 

[jonewer]

I might have the wrong end of the stick here, so apologies if I have it wrong, but isnt 0.7-0.9 ppt an implausibly low amount of acid for a cider?

I mean even golden delicious has an acid content of around 0.2% or 2 ppt....... OP, are you sure you're titration is correct?

 

[Thrupney_Bit]

As you've sulphited the must it's very unlikely that there will be any MLB present. You'll need to get some from a home brew shop (frozen or sterile liquid) or as was suggested to me buy some bottled cider that has been traditionally produced and contains MLB.

 

[Wapiti Dreamer]

Excellent point Thrupney. I'll need to buy some from the brew shop. Finding traditionally brewed ciders in northern California is a challenge at best.

On the titration point made by Jonewer, that figure equates to 7-9 parts per thousand on a TA scale. I don't think that's implausible. Having said that, and being intimately familiar with my poor record in chemistry class, I'll titrate again to be safe.

Thanks for the imput. Much appreciated.

 

[keith1664]

Any chance your increase in acidity is due to the carbon dioxide produced during the ferment (ie. carbonic acid)?

 

[Thrupney_Bit]

You should be able to purchase MLB produced by Wyeasts without too much trouble.

Titration kits do expire so a new one might be in order. Remember that the principal acid in apples will be malic but your kit will only titrate for sulphuric. Total acidity for sulphuric acid should be in the region of 2.9ppt. A better option might be to check the pH is in the region of 3.4 to 3.6. This is the right range for pH and will roughly correlate to the right overall acidity level.

The above acidity/pH figures come from the book by Simon McKie, worth purchasing I'd say! Also, don't forget that acidity and pH are different.

 

[jonewer]

On the titration point made by Jonewer, that figure equates to 7-9 parts per thousand on a TA scale. I don't think that's implausible. Having said that, and being intimately familiar with my poor record in chemistry class, I'll titrate again to be safe.

Oh right, I thought you said 0.7 and 0.9 ppt! I was wondering what apples you used that have so little acid in them......

 

[evanvine]

your kit will only titrate for sulphuric.

Not true!
The NaOH will titrate ANY acid!
H2SO4 is only used as a reference level.

 

[Thrupney_Bit]

Evanvine, if I expand a bit more could you check whether I am applying my science correctly?

My understanding was that the kits titrate for sulphuric acid. Since apple juice from pressed apples is principally malic acid you need to convert the ppt of sulphuric of your must, measured from titration, to the equivalent malic acid. A solution of 2.9ppt sulphuric acid will be equivalent to 4ppt malic acid. Using this ratio I then back calculate my malic acid levels, to calculate a total acidity.

Have I got things completely wrong? I didn't think you could titrate directly for malic acid levels, hence workings above. Back to school for me perhaps?

Thanks in advance