Sunday, December 31, 2006

Extended maceration at home

Sounds like something not to try at home right? But earlier, I said I would be performing extended maceration after a cool fermentation on the '06 Chez Ray vintage. The extended maceration allows for extra contact time between the skins and the new wine, softening and knitting the tannins. I had excellent results in my experiment with this for the '05 Chez Ray vintage. The primary problem I see with extended maceration at home is the invasion of air.

Remember that during primary fermentation of red wines, the skin cap rises to the top with CO2 emission, creating a cover for the fermenting wine, as you see to the left.

"Punching down the cap" is done a couple of times a day to keep the cap in contact with the wine below.

Yet, once the primary fermentation stops, the cap no longer rises, and the new wine just sort of pools with skins in the bucket, looking all tired and oily. Because there is no longer any CO2 release, and because the skins are not rising, this new wine is no longer protected from oxidation. So, to perform extended maceration for a few more weeks, we need to keep the air away from the wine.

Thus, the secret weapon:

Just plain old plastic wrap. I like the Glad Press'n Seal sort, which has a certain stiffness and keeps its shape. But any plastic wrap will do.

By tucking a sheet of plastic flat against the wine and pressing it to all sides of the fermentation drum, we can achieve a perfectly good seal between the wine and the air, allowing for extended fermentation.

I lift each sheet every couple of days to give the must a slight stir. This all worked like a charm last year in warm fermentation temperatures. I'm even more confident fermenting and macerating in the cooler basement this year.


  1. Ray,

    Have a question for you about my wine.

    I am making a Riesling from a kit. It said to leave it in the primary fermenter (bucket) until the gravity dropped below 1.010 which should take 5-7 days.

    I put it in the primary fermenter on 12/26/06 (7 days ago). When I put it in it was 1.080 which was in the range of correct gravities.

    It is now only down to 1.058. I put a crystal thermometer on the fermenter and it is reading a consistent 56 degrees. I have the fermenter in the basement.

    I assume the slow degrease in gravity is due to the temperature in the basement.

    1) Do I need to move the wine to a warmer location?
    2) Do I need to wait till it gets to below 1.010 to move it to a glass carboy?


  2. David,

    Once again, I'd urge patience. Lower temperatures do make for slower fermentation.

    There is however one thing to be concerned with: is the temperature too low for your yeast to continue working? Cote des blancs, for instance, often used with white wines, quits working when temperature moves below the high 50's or so. Check out this chart for info on your particular yeast:

    If you see signs of fermentation (ie, continued bubbling), and if specific gravity is continuing to drop, you're doing fine, and patience is the watchword.

    If temperature is too low for your yeast, and/or if gravity is not dropping and there is no bubbling, then forget my suggestion about patience -- it is time to move!

    Specifically, move the fermentation to a warmer place. You should see it kicking back into gear in a day or so.

  3. Oops, on the glass carboy question... I don't see any particular reason to wait. With reds, you wait to go to glass till after primary fermentation so you can press off the skins. There's no such step with whites, so I see no reason your primary couldn't be continued in glass.

    You'll probably want to rack clean wine off the yeast (gross lees) once the primary has settled out.

  4. Thanks fo the advice. I moved the bucket to the kitchen pantry and the tempmoved to 62 degrees. The fermenttion is back on track and the gravity should be below 1.010 by tomorrow.



  5. That idea with the cling wrap is great! I will be using it for my post-fermentation maceration this year. Thanks for the idea.


  6. Jason,
    Let me know how it goes. I've got some cab and merlot under "wraps" in the basement for their fourth week now, and I'm finding that stirring as little as once a week has seemed fine.

  7. Ray,

    The extended maceration went well. I noticed no increase in volatile acid after the 2 weeks under the press-n-seal. I also kept temperatures around 25C to increase extraction and glycosides (check out this article on the topic ). As an added precaution I blanketed with CO2 once. The wine was amazingly dark and had nice fruit at pressing. I think I’m going to use the wrap for cold soaking as well.

    Good luck with your wine!


  8. Wow, Jason, you've brought this little experiment to a whole new level! It all makes sense though, and the article is an interesting (even if dense) read. Congratulations; and here's hoping the truth shows in the bottle.

  9. Very interested in yr experience on extended maceration. I have a quite tannic red i'm making for 2nd yr. Didnt do maceration last yr and am thinking about doing it this yr. i'm also putting it in a 110L barrel this yr - new Fr oak which i'm little concerned about becaue of tannins. was thinking extended maceration would really help but some of my reading suggests there is a 'magic moment' in the process for when the polymers form long chains and if you dont hit it you can get bitter tannic wines which take several years to 'relax'. Thoughts/experience on that?

  10. Hi, Jennifer, I don't have POV around extended maceration vis a vis oak maturation. I'm thinking they're very different in impact. I'm doing a more formal test this year with an '08 cab and a merlot with same yeast in EM and non-EM. Though still in progress, I'm finding the EM's lost much "brightness" and "tone" in their flavors versus the non-EM's. I'm planning to press right at dryness this year. My WORST tannins occurred in '05, though, when I pressed several brix BEFORE dryness. Those were monsters, still can't enjoy them, but they do seem to be getting better and better. In '06, I tried a cooler ferment, and that lightened the tannins considerably, but at cost of color and intensity (though nice aromas).

    Short story is, none of this is exact science. Any chance you can split your batch, varying either pressing date or ferment temperature?

  11. Good lord. I was wondering myself yesterday why cling wrap wouldn't work!!! THANK YOU for posting this. I have a batch I was going start fermenting today, but now I'm going to wrap it, cold soak it, and give it an extended maceration under film post fermentation. Brilliant!!

  12. Should additional sulfites be added for the extended maceration?


  13. Reasonable question. I did not, as I was planning to put the wines through malolactic fermentation after pressing, and I didn't want to disadvantage that.