Malolactic fermentation

[Muirghein Tarot]

Was doing some research on yeast when I can across this site http://www.winepros.org/wine101/enology.htm (sorry don't know how to make it a link) and was interested in the description they were giving of the benefits of Malolactic fermentation. Will look further into it but I thought I would ask if any of the mead makers here who also make wine 'cough' Oskaar 'cough' could share some knowlage with us about this.
Is this something we can use in mead making or do we already do it and call it by another name?

Tarot.

 

[Dmntd]

Hey Tarot,

Above the text window and directly under the U is a box with a globe, that will make a link.

If you type [ url=PASTE LINK HERE]TYPE TITLE HERE[/url ] without the spaces you'll get a like like this Malolactic fermentation

Dmntd

 

[Muirghein Tarot]

Thanks, not the most computer literate person in the house.
Tarot

 

[Sander]

I'm no Oskaar...
but here's my 2 cents. During malolactic fermentation (some of the) malic acid is converted to lactic acid. The malic acid is present in the grapes. I don't think honey contains much malic acid...

 

[Muirghein Tarot]

Was mostly thinking about it's use in pyments where there would be a little of the maltic acids from the grapes, grape leavings, grape juice or what ever form of grape like object you want to add.
Will be getting about ten to thirty pounds of muscadine grapes in a few weeks. They are still small and green at the moment but the vines are full. The vines run forty feet up a tree so will be laying out tarps and shaking hanging vines.
They are very different from most types of grapes but there is a bitter quality that I would be willing to bet is maltic acid.
Tarot.

 

[JamesP]

Apples have Malic acid - does anyone force an MLF to reduce the harshness of the Malic acid in their cysers??

 

[Oskaar]

Sorry for the truant response. I've been very busy at the office and my free time this week is pretty much non-existant. I'll expand on this a bit more in a subsequent post.

Based on what I've read and in conversations with others honey contains: acetic, butyric, citric, formic, gluconic, lactic, malic,pyroglutamic, and succinic acids; and the major organic acid is gluconic acid. As I understand it gluconic acid is formed during enzymatic glucose-oxidase action on glucose.

Honey doesn't contain a lot of malic acid so in many cases MF (or the more politically corret MLF) is not a requirement to reduce malic acid to lactic acid. However there is malic acid present so MF can occur and be encouraged. Malic acid contains two acid groups and during MF one of those groups is reduced yielding lactic acid which is less "bitey" on the tongue and palate.

Cysers do benefit from MF in my opinion specifically due to the reduction of the second COOH acid group which reduces the "apple cider vinegar" character, aroma and taste in cyser. But that is up to the individual and their own taste buds. Characteristic effects are a smoother, creamier, buttery flavor which is related to diacetyl produced during the malo-lactic fermentation.

Oenococcus oeni is the most commonly used bacterium in the wine industry to conduct MF to my knowledge. Coupled with barrel fermentation and lees aging, MF contributes character and structure to some of the finest Chardonnays in the world.

Hope that helps,

Oskaar

 

[SteveW]

Interesting.

I've ordered a malo-lactic culture to add to the 7 gallons of cider I have maturing - it was about 60% bramley juice to 40% cox with a little crab and quince for tannin, and while it's palatable I'm hoping to make it a little less sharp and a little more rounded. I sulphited my juice after pressing it, so I'm not confident of a natural malo-lactic fermentation.

I had some excess bramleys left over, and no dessert apples to blend, so I thought I would experiment with cyser. I have three one gallon demijohns going:

(A) 1lb honey + apple juice, Young's cider yeast, OG 1.072

(B) 1lb honey + grape concentrate + apple juice + sugar, Young's high alcohol yeast, OG 1.115

(C) 1lb honey + pressed grape juice + apple juice + sugar, Young's high alcohol yeast, OG 1.092

They've all been racked off once after a couple of weeks of vigorous fermentation and then fed a little extra honey, and all are still fermenting slowly. I want (A) to finish slightly sweet and moderately strong. I thought the cider yeast would have only slightly higher alcohol tolerance than an ale yeast, and would have snuffed it by now, but perhaps it's a little tougher than that. I want (B) to finish strong and sweet. I want (C) to be moderately strong and dry. I'm considering bottle conditioning C in champagne bottles.

Given that one sachet of malolactic culture will be plenty to inoculate my cider with enough left over for all three, I'm trying to decide which if any to treat. I think (A) and (C) are likely to benefit most from a reduction of acidity - (B) might be sweet enough to carry it off, and it might also be too alcoholic for the liking of the culture.

What do you think?

 

[akueck]

Apples have a tendancy to "extend" the alcohol tolerance of many yeast strains. I have personal experience with D-47 going to 17-18% in cysers but only 14-15% in traditionals (it's listed for 14%). So you might not get the sweet results you're looking for without stabilizing (many options there) and backsweetening.

Step-feeding (adding honey/sugar periodically throughout fermentation) will also extend the alcohol tolerance of your yeast, so don't add more honey now without stabilizing first or you may get unexpected results.

 

[Medsen Fey]

If you are aiming for sweet meads, be careful with the malolactic fermentation. The bacteria will eat sugars (along with other things like citric acid) and produce large amounts of volatile acid (vinegar like) and diacetyl (some is good, too much is bad). Oxygen exposure tends to promote this as well so I understand.

You might want to think seriously about letting the batches go dry before performing the malolactic fermentation, then stabilizing and backsweetening to get the sweetness level you desire. That way you can get the benefit of MLF without the volatile acid.

Good Luck,
Medsen

Oh, and I shouldn't forget-

Welcome to the new and improved* GotMead? SteveW!​

*Other sites will be GREEN with envy! :blob10:​

 

[SteveW]

Thanks, for the thoughts and the welcome!

I didn't realise that there was likely to be a problem with unwanted metabolites in the presence of high sugar levels - that's a really important piece of information.

I think I'll leave batch B alone - that's the strong sweet one. Batch C I meant to finish dry anyway. Batch A - the lower alcohol batch - is the question. I wanted to leave it with a little residual sweetness to balance the acid from some very tart apples, however if I can knock the acid back, that becomes less of a consideration (and dessert wines apart, I prefer most things dry).

OK, I think that's a plan - I'll leave B alone, and I'll finish A and C dry with a ML culture.

 

[Smarrikåka]

If a mead with slight sweetness starts out good, but picks up some faults after about half a year, is spontaneous malolactic fermentation a plausible explanation?

 

[Oskaar]

If it's hazy and fizzy that's MLF generally.

 

[Smarrikåka]

Hazy for sure, not really fizzy though. If so, very, very slightly.

Another person made this mead, so I'm not sure if sulfites were used or not. It was made in May, and I recieved it in early November. He was quite proud of the mead, but when I tasted it, I detected clear off-tastes, and when he re-tasted he detected it too, and thought it had contacted some kind of infection. Now, a bit over a month later, the off-tastes have mellowed and are not as harsh any more, even though the bottle has not been airtight since then. So I was thinking, that perhaps it was a a case of ongoing malolactic fermentation, when I first tasted it in November.

 

[Medsen Fey]

If a mead with slight sweetness starts out good, but picks up some faults after about half a year, is spontaneous malolactic fermentation a plausible explanation?

Do you have the recipe for the mead in question?

 

[Smarrikåka]

Not really, but I can tell you all the things that I know about it. It's two meads, actually, though made in similar ways, and they both suffered from the off-taste, when I first tasted them.

What made the two different, was that they were two different kinds of methelgins. In one the water used had been cooked with branches of Juniper tree before fermentation, and the other one was spiced with mint.

They were both made from honey that came from a mixed forest coastal area, which was amber in colour. A sugar addition of 0,5 kg of dextrose was also made. I don't remember the total volume or the amount of honey, but if I recall correctly there was enough sugar to produce around 11 abv. After fermentation they were backsweetened with about 1kg each of honey (like I said I don't really remember but I think it was 20l batches or so). I'd call them more dry than sweet in terms of taste, so I wouldn't be surprised if some of the backsweetened honey had fermented.

I know nothing about how racking was done. The meads are both slightly hazy in apperance, but don't have any bottom sediment.

The off taste that existed in both was very similar to how the juniper branch spiced mead tasted, except it appered as an after-taste, and left a kind of bitterness in your mouth that wasn't pleasent (also it existed in both meads, and in the mint one it was very clear that it didn't belong). This off-taste is currently no longer there, and according to the maker, the meads were great in the early months after completion.

Edit: I believe the yeast used was one meant for fortified wines. No strain information. Though it is also possible that it was an ale yeast, but I don't think so.

 

[Smarrikåka]

Does anyone have any idea what might have been going on?

I have come to the conclusion that it's doubtful to have been malolactic fermentation. There shouldn't have been much malic acid contained within those recipes, and there shouldn't be much of it produced during fermentation either.

But might there be some other kind of "phaze" going on in an unstabalized mead after a few months of storage?

 

[wayneb]

Without being able to taste the mead, I can't speculate on what might have caused it to "haze up" and produce the off-tastes that you mentioned. Most likely some sort of organism has taken up residence in there (and especially since you know nothing about the circumstances of racking or bottling, nobody can vouch for the sanitisation protocol that was followed). But at this point it could require something like a lab culture to try to isolate exactly what microorganism is the culprit.

I have not in my experience seen a previously clear mead spontaneously "haze up" after storage, unless fermentation re-started or it became infected somehow.

 

[Smarrikåka]

Alright. I can't vouch for if the hazyness just appeared, or if it was there from the start either. But there's never been any bottom layer sediment in the bottles.

What I was trying to figure out from this, is if there might be some benefit/downside in leaving a dry mead unstabalized for a few months (not on lees) before you stabilize it, and possibly sweeten it.

I doubt anyone has done a comparison like that, but maybe someone has some useful information.

 

[wayneb]

I can't speak to any downside, since leaving a mead dry to age a bit on its own merits before deciding on stabilisation/backsweetening is what I always do with my meads. Some of the dry "paint thinners" that I have made in the past have markedly improved - a few enough to allow me to leave them dry - after 6 to 9 months in a bulk carboy past when they've completely cleared and been racked off of lees.

I have not experienced anything like the onset of a haze after the sweetening, unless the honey that I'm using to backsweeten is raw. Then, in some cases (and for only some honey varietals) a haze will be introduced, but it usually settles out and clarifies with additional aging time.