maloatic fermentation?

[Cazamodo]

How and what is this?
I see it mentioned all over the place, and a quick google told me that its to lower the lactic. malactic acid in teh cider? is this correct?

also, whats teh adbvantage of this, and how do you go about doing it, as i have cider that has finished fermenting for aroun d 2 weeks, and just still sitting in the primary

 

[Teromous]

The spelling and format of your thread is driving me nuts, but anyway...

Malolactic fermentation is simply malic acid being transformed into lactic acid by the bacteria in your brew. When you taste a sharp acidic juice from the apple, it is high in malic acid. When something tastes oily then it's high in lactic acid.

Your primary fermentation is where the yeast turns sugar to alcohol and CO2, and eventually dies. Your secondary fermentation is when lactic acid bacteria convert the malic acid to lactic acid and CO2. This will happen spontaneously.

If you are impatient, extremely bold, or very experienced, you can induce malolactic fermentation on your own. I know White Labs sells some:

White Labs

Edit:

I forgot to address your question about why it is done. If you have a very acidic cider, undergoing malolactic fermentation will reduce the acidity and make it more palatable. It also "rounds out" the flavor a bit. Some other things I forgot to mention are temperature and SO2. Low temperatures and high levels of SO2 are inhibitors.

 

[gregbathurst]

Cider is very high in malic acid so in my experience goes through a malolactic (MLF) very easily. The cider needs to be at a pH above 3.3 and low in camden (SO2). Doing your own mlf is fairly easy but a bit expensive and the culture needs to be stored cool, freezer is best. It takes a while to go through, 2-4 weeks, so needs to be done early, I do it straight after the main activity of primary has subsided.
There are a few advantages. It stabilises your cider, if you want still cider you can be sure it wont suddenly get a bit fizzy from a wild mlf. Also occasionally a wild mlf will produce off flavours and ruin your cider or wine. A cider that hasn't gone through mlf can't really be considered stable, and you can't be sure its gone through unless you pitch it yourself.The CO2 produced gives your cider extra protection from oxidation.
I like the less sour cider after mlf, and haven't noticed any oiliness or butteryness, I think that is more a wine thing.

 

[staggerlee]

If your primary ferm is complete, can you induce a malolactic fermentation and use that fermentation to bottle-carbonate with, or is that a dangerous prospect?

 

[gregbathurst]

I don't think you would get enough CO2, but you could try it and let us know the result.

 

[CvilleKevin]

Greg - I've found that my ciders will usually go through MLF (or what I assume is MLF) on their own if left to sit for a while in the secondary after they have been crashed. They sometimes have a sour candy sort of tartness after the crash, which I understand is malic acid, and this usually works itself out OK

I just did some batches where I added DME and they came out sour, but its not the sourness that I have associated with malic acid. It tastes more like a citrus acid sourness. I know that there is some citrus acid in cider and it tastes like the DME caused that acid to dominate after the ferment. Does malic acid ever tastes like citrus and does the malolactic culture help with that? Which one do you use, white labs? Do you just pitch it like it was one of their yeasts? Thanks.

 

[gregbathurst]

Kevin, you are right that most cider will go through mlf if left to itself, especially if you don't use much camden. I don't know anything about citric acid in cider, I don't think it would have much impact on the flavour. I pitch mlf culture to speed up the process and for safety and certainty, and for the extra co2 protection.
I don't have much choice of supplier, I use an australian company called winequip, whatever they sell in small quantities. They post it with an ice pack, it really needs to be kept cold, so you can't order it from overseas. I don't think the choice of culture is so important.