Newbee MLF questions

[ZebraB]

1) I have had some wines that the manager at the local Total wine store called "Rich". It definitely was too "buttery"for my taste.( ie MLF impact in a pinot noir). I plan on doing MLF post fermentation. Is there a way to measure the impact of MLF and see if the "buttery" taste will be strong? (chromatography test??) Of do you do taste tests when stirring the lees and stop with lysosome if it appears to be getting stronger but MLF has not completed?

2) I have bought 3 G, (2) 1G and 1/2 carboys and plan to minimize waste. However, is it ok to top off with commercial wine when a tad short prior to MLF completion?


3) I imagine that you will have to pull some wine off to put a paddle in to stir the lees during MLF. Is it ok to put back the wine pulled off to stir if in a sanitized container? Or is this risky since SO2 has yet to be added. (Note: I do not have any type of gas to purge airspace)

 

[stickman]

Normally the bacteria consume malic acid first and then transition to consume the citric acid, at that point the diacetal (butter) content begins to increase. If you sulfite the wine immediately the butter will be preserved, however if you wait for several days or longer, the butter will be lost, it is usually consumed by the bacteria and yeast lees.

A small amount of commercial wine shouldn't be a problem, but take care to ensure the commercial wine doesn't contain much residual sugar.

Stirring the lees isn't always necessary during MLF, with a red wine I would say only stir if there is a problem with completion. Young red wine, less than 4 months old, can loose color if the lees are kept suspended, this is particularly true for wines like Pinot Noir and Sangiovese. If you need to stir, a racking cane works well without displacing too much wine.

 

[mainshipfred]

Normally the bacteria consume malic acid first and then transition to consume the citric acid, at that point the diacetal (butter) content begins to increase. If you sulfite the wine immediately the butter will be preserved, however if you wait for several days or longer, the butter will be lost, it is usually consumed by the bacteria and yeast lees.

OK, you got me confused on this one. I understand it consumes the malic first but never thought about the time frame. What confuses me is the several days or longer for the diacetal. My secondaries take 2.5 to 3 months until I'm comfortable they are complete. I've never had a buttery taste in my reds but at what interval do you wait your given time. I'll apologize before hand if I misunderstood your post.

 

[stickman]

I was providing the information for the times when diacetal is produced, but diacetal isn't always produced in noticeable quantities, especially if you are not constantly checking. Some bacteria are known for greater production of diacetal, and even the bacteria initial cell count can influence the production. Once the malic is finished or nearly finished that's when the diacetal content starts rising and usually continues through citric metabolism. Leaving the wine on the lees for a period of time after ML completion allows the yeast to consume the diacetal. For those making a white wine where diacetal is desired, you have to taste and add sulfite when the desired diacetal level is achieved. The following paper from Scott Lab provides some details.

 

[ZebraB]

Thanks again. This place has all the answers. I have already purchased the alpha. Since it is medium I should be ok by starting with a larger side of the recommended dose, not stirring and tasting once complete to see if the diacetal level is ok. If not wait a little more time to add the SO2.

 

[BI81]

I was providing the information for the times when diacetal is produced, but diacetal isn't always produced in noticeable quantities, especially if you are not constantly checking. Some bacteria are known for greater production of diacetal, and even the bacteria initial cell count can influence the production. Once the malic is finished or nearly finished that's when the diacetal content starts rising and usually continues through citric metabolism. Leaving the wine on the lees for a period of time after ML completion allows the yeast to consume the diacetal. For those making a white wine where diacetal is desired, you have to taste and add sulfite when the desired diacetal level is achieved. The following paper from Scott Lab provides some details.

Thanks for posting this, this will be my first vintage in barrel and I’ve been debating if I should stir during MLF. This has just pushed me to the not stirring camp.