Malo lactic ferment

[Nana Caz]

We are in the alleged 'fortunate' position of having a number of demi-johns that are still producing a multitude of tiny little bubbles rushing up to the surface. We believe this to be a malo-lactic fermentation. Apparently this is something that wine makers should be pleased about. Initially we felt rather smug but ...well, plain ticked off is the polite terminology for how we're feeling now. We have "new" wines that are approaching the bottling stage and these more mature wines are still fizzing away happily.

What should we do?
Kill off the ferment...can it be killed off?
Keep waiting and hoping that one day - soon!! - it'll all be over?
Is there anything we can do?

I don't have a scooby how we managed to achieve this - didn't do anything any differently and yet, the bubbles are still very definitely there! I've tried racking a couple of them - made no difference at all. I've added Campden tablets; and then that thingymajigger that stabilises the wine when added with a Campden tablet so there are no geraniums in the wine...still there!

It's doing my head in - anyone else experienced this? If so please, what did you do?

Nana Caz

[dave45]

What's the SG of the wine?

Is there a problem with just leaving it a little longer?

[MKG]

C'mon Caz - you know the rules ...

What kind of wine?
When did you start it?
How much sugar did you use?
Is it in a cool place, a warm place - where?

As you've added Campden and Sorbate, it ain't yeast that's doing it, so a malo-lactic ferment is most likely. And honestly, you do NOT want to stop it (not that you can very easily).

We await the info with bated breath.

Mike

[gregorach]

We believe this to be a malo-lactic fermentation. Apparently this is something that wine makers should be pleased about.

So some claim... As a brewer, even a suggestion of lactic acid sets off all the alarms in my head. Don't like it at all.

I don't have a scooby how we managed to achieve this - didn't do anything any differently and yet, the bubbles are still very definitely there!

Infection with either Lactobacillus or Pediococcus most probably. They're everywhere!

[Nana Caz]

Ok, OK, it was worth a try! Just being lazy and couldn't be bothered going down to the wine cellar [aka the back cupboard - the cold back cupboard - under the stairs!] so here goes...

At this point in time I have:
1 d/j apple & rowan - 2008
4 apple & elderflower - 2009
1 apple - 2009

Have bottled and disposed of one of the apple & rowan wines from 2008 which went down very nicely thank you. Both had 5lbs apples, 1lb rowans to 2 3/4lbs sugar and 1/2lb raisins. One long gone and the other still bubblin'!

The apple & elderflower is my second crack at that recipe - first time in 2008 and it was lovely...with one helluva kick to it!

I used 3/4 pt elderflowers, 1lt clear apple juice, 3lbs sugar. Did everything as usual - once finished fermenting, racked and kept in the "wine cellar". 2009 batch is still going strong and there is nothing to see in the d/js; just a gorgeous clear liquor! The 2010 batch is sitting beside its mates and it's had a second racking already and none of those 4 d/js are showing any signs of bubbles and/or a malo-lactic ferment

The apple wine in 2009 is a variation of the apple & rowan recipe; no rowans and extra apples. Again, one d/j is history and this one...well...isn't!

I guess I can't get my head around why there should be such differences in batches of the same wines. Apple & elderflower 2009, they all went the same way...bubbling! I must tell you tho' that they smell great and the accidental sip that I had when racking them certainly bodes well, so I have no concerns that they are going to be "bad" wines. I'd just like to drink them sometime soon!

Got some rhubarb wines, silver birch wines - they smell/taste ab fab - and banana wine on the go, all at various stages. The banana tastes like raw spirit just now, a lovely colour tho! Nothing to do with anything, just thought I'd say...

Thanks for getting back to me,

Caz
PS: You breathing yet Mike?!

[MKG]

Phew - bating breath for that long is painful!!!!

It's apples, Caz - they're high in malic acid. If anyone knew why some wines spontaneously develop an M/L reaction and some don't, they'd be in for a fortune. People would pay good money for that knowledge.

Any of the wines you mention finished their yeast fermentation a long time ago and, as they don't smell or taste off in any way, it's 99.999999999% certain it's an M/L. And the good news - if they're clear, you don't actually have to wait to drink them. Some commercial wines are sold after an M/L - Chardonnays in particular - but at least one rose used to be sold with an active M/L going on. All it means is that the wine will have a mild fizz on the tongue (frizzante). Or you can wait - it can't go on forever.

Oh - your banana. You'll probably have to wait an appreciable time for that one. Pure banana wines are rare - principally because they spend a long time smelling and tasting like a petrol derivative. The more usual use is the addition of, say, one banana (peeled, boiled and strained, then just the liquid used) per gallon. It can delay the wine clearing, but when it does clear, it falls absolutely star bright.

Mike

[gregorach]

It's apples, Caz - they're high in malic acid. If anyone knew why some wines spontaneously develop an M/L reaction and some don't, they'd be in for a fortune. People would pay good money for that knowledge.

Huh? There's nothing "spontaneous" about it. It's bacterial:

MLF is conducted by lactic acid bacteria (LAB), of the genera Lactobacillus, Oenococcus, Pediococcus, and Leuconostoc.
Not all LAB are desirable for MLF. Oenococcus oeni (formerly Leuconostoc oenos) is the most beneficial, and probably the most frequently occurring species of LAB in wine. Species associated with wine spoilage are generally members of Lactobacillus and Pediococcus genera. The Lactobacillus genus, for example, can cause acescence (excessive acetic acid) by metabolising sugar or tartaric acid [Radler and Yannissis, 1972]. Many LAB metabolise pentoses, tartaric acid and glycerol. The term "malolactic fermentation bacteria" (MLB) is commonly used to refer to those LAB strains which are more desirable for MLF. They are more resistant to low pHs such as those in wine (and in which other LAB find it more difficult to live) and they prefer to metabolise malic acid over sugars and citric acid (and they do not metabolise tartaric acid or glycerol). Oenococcus oeni, a desirable strain, may also metabolise glucose to produce carbon dioxide, lactic acid, acetic acid and ethanol (it follows the heterolactic pathway (6-PG/PK pathway)) [Garvie, 1986; Axelsson, 1993; Henick-Kling, 1993] but will degrade malic acid before degrading any glucose present under non-growing conditions.

Source: http://www.brsquared.org/wine/Articles/MLF/MLF.htm (Very thorough!)

And if you got an "accidental sip" whilst racking, then that will likely be where the contamination (or inoculation, if you prefer) occurred. Your mouth is hoatching will all sorts of bacteria, so if you're actually sucking on your tubing to start the syphon, you're practically guaranteeing contamination of some kind.

[MKG]

OK Dunc, you microbiological pedant

Spontaneous was the wrong word - I suppose I meant "otherwise unexplained". M/L ferments are intentionally induced in the production of some commercial wines but you need lab conditions to ensure that the correct strain is used - your quoted article points out the dangers of the wrong one getting in. As far as home winemakers are concerned, M/Ls are either a form of magic or a method of producing mouse urine. If you get the right one - which Caz obviously has - it's great.

Mike

[gregorach]

OK Dunc, you microbiological pedant

Sorry, I just can't help it. This is what comes of setting up a home lab. (Just got another delivery of glassware, autoclave indicator tape, and my second magnetic stir plate...)

You're right - the trick is not so much getting LABs in there, it's getting the right ones... (Although, I have to say, in my defence, there's a lot of amateur winemakers who don't seem to be particularly discerning on that point. I've encountered booze, which the maker was apparently happy enough with to enter in competition, that smelt of bacon...The flavour was, well... "indescribable" would be about as polite as I could muster. )

[frozenthunderbolt]

I've encountered booze, which the maker was apparently happy enough with to enter in competition, that smelt of bacon...The flavour was, well... "indescribable" would be about as polite as I could muster. )

Ok, now you have my interest - I disbelieved a collegue of mine who said she had tried a homemade moonshine that tasted of luncheon sausage. What in the hell rare microbial infection could cause a porcine wine (and by association spirit).
It certainly can't be common - i'm yet to come accross a book that lists 'tastes like pig' as a fault

[gregorach]

I have absolutely no idea, and to be honest, I'm not sure that I want to know. Brettanomyces gets all sorts of weird descriptions though, including "farmyard", so that might be a possibility... If I ever encounter it again, I'll try and remember to take a sample and see what I can culture from it. (It was "beer" actually, rather than wine, but made by a winemaker for a winemakers beer competition. None of the other entries I tasted were up to much either... )