Apple juice question

[Kees]

Today I had a cider making course run by professional cider makers in a local heirloom varieties orchard.
We were allowed to collect our own apples and the were milled for us.
These are the juice's specs: SG 1044, pH 3,0 and titratable acid 7 g/l.
We were told spontaneous malolactic fermentation will not occur under thes circumstances. We were advised to add sugar to raise ABV.

I am looking for reocmmendations re. low-pH-resistant malolactic bacteria to add.
Any other options to raise sugar concentration? I was thinking of addig sweet apple juice or pear juice rahter than sugar. How about that?

 

[Steveruch]

How strong do you want it? I don't bother adding any sugar. Using EC1118 yeast it gets down close to 1.000 from 1.045 giving close to 6%.

 

[Kees]

About 6% ABV

 

[gregbathurst]

You should check the pH after primary, often it will get a bit higher, then you should be able to do MLF.

 

[Steveruch]

About 6% ABV

You can get close to that without adding sugar with the right yeast.

 

[Kees]

We won't be adding yeast, let the wild yeasts do the work. Our teacher told us that you usually get a lower ABV because some sugar will be converted into different molecules than alcohol and CO2. he reckons it will be approx 4,8%

 

[scott.campion]

How much do you have? Possible to split the batch and do half and half to experiment?

 

[Kees]

That's a good one. I'll see whether that is possible. ATM the juice is in climate-conditioned room in the orchard organizing the course.

 

[Kees]

More than a week later no activity in the waterlock yet. Should we add yeast now or give it some more time? Would adding yeast help to prevent formation of off-flavours?

 

[madscientist451]

Your fermenting vessel may not be sealed all the way, so that's why no airlock activity? Pull a sample and take a gravity reading before doing anything.

 

[scott.campion]

Also, can you clarify the timeline? You pressed the apples on the 16th it looks like but I think didn’t take home the juice right away? When did you put it in the ferment or with the airlock?

 

[Kees]

We pressed the juice 16th, the teachers, who are professional cider makers, put it in a brewing vessel in a climate-controlled room. Not sure what the temparature is there but they told us the climate control wasn't working well. So I guess it won't be much lower than the open air i.e. at least 10 ⁰C.

 

[scott.campion]

I was asking because it’s possible most of the fermenting happened before you had it under airlock? Unlikely but wasn’t sure.

I agree with @madscientist451 above - Take a sample and see what is going on first. If you don’t have a hydrometer to take a specific gravity, just give it a taste. Is it still sweet, indicating that the sugar hasn’t been fermented away? If so (or if measured SG is still high) then I personally would try adding yeast. I used a champagne yeast in some juice that had a starting gravity of 1.040 and it fermented quite happily.

 

[Kees]

Update: Dec. 6th Lalvin 71B was added by course organiser and day before yesterday SG down to 1.004.