The recurring nightmare: Stuck blueberry

[Rappatuz]

Picked 10,5 kg (23 pounds) of wild blueberries this summer and tossed them in the freezer. Decided to go with 800 g berries per liter (6,7 pounds per gallon) to make a flavorful wine. I know that low pH may pose a challenge when making wine with blueberries. I'm pretty new in this game and don't own a pH meter, unfortunately. I crossed my fingers and hoped for the best. Of course it got stuck ... almost immediately. Check out my log:

9/20: Mashed 10,5 kg blueberries, added 5 l water, 2,1 kg sugar and 1 g potassium metabisulfite. SG: 1,082.
9/21: Added 10 g pectin enzymes and made a starter with Mangrove Jack's R56 yeast (5 g).
9/22: Added 2 g Wyeast Beer Nutrient Blend and the starter, which was bubbling happily.
9/23-27: Berries float to the top and are pushed down once a day.
9/28: Took out bag with blueberries. After squeezing; 13 l must in the bucket. SG = 1,078.
9/30: Filtered a sample through a coffee filter and measured SG (= 1,076), just to rule out the that the reading would be (severely) skewed by floating particles in the must.
10/1: Added 6 g DAP (diammonium phosphate).
10/2: Must covered in a purple bubbly layer of "something" (see attached image). An apparent "fizz" sounding in the bucket. Still smells and tastes fresh. SG = 1,076.

There are several signs of fermentation but the SG is almost where it started after nearly two weeks. What worries me is that the batch will start spoiling when there's no alcohol to protect it.

I have several yeast strains in the fridge and will most likely make a new starter tomorrow. Any advice would be great.

 

[hounddawg]

drought i can be much help. but first i stir using a drill, that breaks up your solids for more surface for your pectinase or pectic enzyme to work on, use your taste to get your PH level. taste, taste, taste, and i tend to use K1V-1116 or EC-1118 as my yeasts,,, good luck,
Dawg

 

[Rappatuz]

drought i can be much help. but first i stir using a drill, that breaks up your solids for more surface for your pectinase or pectic enzyme to work on, use your taste to get your PH level. taste, taste, taste, and i tend to use K1V-1116 or EC-1118 as my yeasts,,, good luck,
Dawg

Thanks, Dawg. It tastes great and to my buds, the acid level is just right.

I have both K1V-1116 and EC-1118. I think I might go with K1V-1116 for a second try.

 

[Rappatuz]

Today I measured SG = 1,070. It has dropped 0,006 since yesterday. I think the yeast just might be picking up some speed Very happy with this development.

Unless someone strongly advice me to pitch some more yeast, I think I'll let it roll and monitor it closely.

 

[user 36973]

I believe your issue is the stemming from the low pH most blueberries tend to run at. My last batch of blueberries came in at a pH of 2.88, low enough to make the yeast struggle.

I suggest you immediately blend in 28g (2g/L) of potassium bicarbonate or 21g (1.5g/L) of calcium carbonate. I did a mixture of half of each. This will raise your pH to about 3.2 where the yeast will be happy and get going. It also would not hurt to add 5g of the V1116, properly hydrated and acclimated. I haven't used R56, so can't comment on it.

This addition will lower your titratable acid (TA), which is probably needed anyway even with your water dilution. Even the juice tastes balanced now, the acid is being offset by the very high sugar level. So when the wine is done fermenting, it will seem tart. You probably are planning for a sweet wine when you are done anyway and should target your TA, while monitoring the pH if you can.

Also, you should purchase an acid titration kit so you can measure the TA in your wine/juice. The kits are under $20 and guide your decisions for achieving consistent wines. The TA is what your mouth actually tastes when you drink the wine, since it is your mouth that produces saliva as a means of neutralizing the acid. Note that you do not taste pH, just TA. The pH is important for biological activity (yeast, bacteria) and spoilage risk (oxidation). A pH meter is a good $90 investment if you plan on making fruit wines since the pH can vary much more wildly with fruits other than grapes.

Cheers

 

[Rappatuz]

I believe your issue is the stemming from the low pH most blueberries tend to run at. My last batch of blueberries came in at a pH of 2.88, low enough to make the yeast struggle.

I suggest you immediately blend in 28g (2g/L) of potassium bicarbonate or 21g (1.5g/L) of calcium carbonate. I did a mixture of half of each. This will raise your pH to about 3.2 where the yeast will be happy and get going. It also would not hurt to add 5g of the V1116, properly hydrated and acclimated. I haven't used R56, so can't comment on it.

This addition will lower your titratable acid (TA), which is probably needed anyway even with your water dilution. Even the juice tastes balanced now, the acid is being offset by the very high sugar level. So when the wine is done fermenting, it will seem tart. You probably are planning for a sweet wine when you are done anyway and should target your TA, while monitoring the pH if you can.

Also, you should purchase an acid titration kit so you can measure the TA in your wine/juice. The kits are under $20 and guide your decisions for achieving consistent wines. The TA is what your mouth actually tastes when you drink the wine, since it is your mouth that produces saliva as a means of neutralizing the acid. Note that you do not taste pH, just TA. The pH is important for biological activity (yeast, bacteria) and spoilage risk (oxidation). A pH meter is a good $90 investment if you plan on making fruit wines since the pH can vary much more wildly with fruits other than grapes.

Cheers

jgmillr1, how how many lbs of blueberries did you use per gallon when getting a pH of 2.88?

First time trying R56. Rumored to be really great for dark berries like blueberries and blackberries.

Never used potassium bicarbonate or calcium carbonate before. Are these additions tasteless (not considering the acid reducing effect, of course)? I see EC Kraus doesn't recommend adding potassium bicarbonate while a fermentation is ongoing (Acid Reducing Crystals).

Really hard to tell at this point, but it may be true that the must will be too tart after most sugar has been consumed.

Advice much appreciated.

 

[user 36973]

how how many lbs of blueberries did you use per gallon when getting a pH of 2.88?

I got about 1 gallon per 10 lbs of blueberries. Depends on your pressing efficiency.

Never used potassium bicarbonate or calcium carbonate before. Are these additions tasteless

The potassium bicarb can produce a salty note if you add upwards of 3g/L or more. It is tasteless otherwise. The calcium carbonate has no noticeable taste but can take a few months and some filtration to clear. A balance of the two can work well. There is no problem with adding these during fermentation.

To be on the safe side you could just add the potassium bicarb and not worry about the calcium slow settling.

 

[Rappatuz]

I got about 1 gallon per 10 lbs of blueberries. Depends on your pressing efficiency.

If you used pure blueberry juice, then your must probably had a lower pH, considering my must has been diluted with water.

The potassium bicarb can produce a salty note if you add upwards of 3g/L or more. It is tasteless otherwise. The calcium carbonate has no noticeable taste but can take a few months and some filtration to clear. A balance of the two can work well. There is no problem with adding these during fermentation.

To be on the safe side you could just add the potassium bicarb and not worry about the calcium slow settling.

Good info! I don't mind waiting if it leads to a great end result. At the same time, I don't have a filtering device. May calcium carbonate be floating around even a year after adding it to the must (I usually bottle after about a year)?

 

[user 36973]

The calcium should settle by a year, but you could just use the potassium bicarb an not worry about it.

Yes I use 100% blueberries and negligible water. The pH probably isn't drastically different with water dilution because of the strong buffering of the fruit acids. Regardless, the yeast will be happy to have a higher pH.

 

[Rappatuz]

The calcium should settle by a year, but you could just use the potassium bicarb an not worry about it.

Yes I use 100% blueberries and negligible water. The pH probably isn't drastically different with water dilution because of the strong buffering of the fruit acids. Regardless, the yeast will be happy to have a higher pH.

Gotcha! SG has dropped steadily by 0,006 points each day and is now at 1,052, which puts it at 4 % AVB. Rolling along slowly, no need to eat the sugar all at once.