cloudy after 6 months

[happymondays]

I guess the question I still have is, how much loss of aromatic elements occurs with aggressive de-gassing (whatever the method employed)? I mean, we make a big fuss about not heating honey to avoid such losses, and then we shake the heck out of it (or power suck it) and blow off enough volatiles that it makes the whole house smell good. Would we be better off just letting it sit and de-gas very slowly over time?

Medsen you have got me thinking about this now, I haven't got the experience of you guys so bear with me, if left alone will meads naturally de-gass themselves then, I wonder if the vigorous de-gass can in fact lose some characteristics of the mead mmmmm.
You know thats what I like about these forums its the bouncing of ideas that gets you thinking! :icon_study:

Regards Scott.....

 

[Medsen Fey]

If left to sit, the CO2 will gradually come out of mead, just as if you leave a soda sitting it will eventually go flat. The intermittent rackings will also de-gas the mead.

I just wonder if you retain more aromatic elements if de-gassing happens slowly. In winemaking, fast fermentations with vigorous CO2 blowoff are felt (by some authorities) to be detrimental to aromatic finesse. Has anyone in winemaking studied the de-gassing rate, and the effect on aromatic components?


Edit
I did find a thread on the WinePress site that talks a bit about degassing. One of the "experts" felt that vaccum degassing doesn't strip esters significantly from wine. I would love to see some data on this.

 

[wayneb]

Edit
I did find a thread on the WinePress site that talks a bit about degassing. One of the "experts" felt that vaccum degassing doesn't strip esters significantly from wine. I would love to see some data on this.

Medsen, I'd love to see the data, also. If you are successful in your efforts to track this information down, please share! I don't know that the position of moderator on a web board necessarily qualifies anyone to be considered an "expert" in the field, as I've seen some patently wrong statements expressed with enthusiasm by such experts on other sites, so I don't necessarily accept the anecdotal descriptions documented in that WinePress thread... although they are somewhat consistent with my own observations. NOTE: Oskaar is the notable exception in this case. I suspect that there are few if any individuals in the world more knowledgeable about meadmaking as he is at present, and he does a damned fine job of moderating "Gotmead?", too.

I'd still like to see some quantitative experimental data either supporting or conflicting with the opinions expressed in that WinePress thread.

 

[Oskaar]

OK I took a look at a few things, and have some interesting notions, but, I'm going to post up some references that are associated in certain ways that will hopefully provide fuel for some interesing discussion.

Here's one paper from the AJEV that discusses some interesting findings concerning vacuum filtration and some results that were a bit different then what was expected.

Also note the year the paper was published. This is how far in front of meadmaking the winemaking industry is, and is a pointed reminder how much we can fast-track mead research and methodologies by simply studying wine research and using similar research processes and methodologies in meadmaking.

Cheers,

Oskaaar

 

[Medsen Fey]

Thanks Oskaar,

That article is very interesting. They did mention that in cases where oxidation was prevented, the vacuum filtered wine was equal to the free run product except for varietal character, and I wonder if that represents the loss of volatile components.

I appreciate your sharing the information, and I will keep looking around for some other data.

Thanks again,
Medsen

 

[wayneb]

Well, reading this paper leaves me with more unanswered questions than it resolves. First, this is vacuum filtration, so there are two processes at work on the wine treated this way. In addition to the vacuum, which is used to move wine through the filter slurry deposited on the inner surface of the drum, there is also the action of the diatomaceous earth filter material on the wine. Finally, the composition of juice from pressings is significantly different than that of free-run, so there is no surprise that the "varietal" character may be missing from pressed juice treated in this way. Medsen, I don't think that you can read the summary conclusion statement about loss of varietal character and interpret that to mean the vacuum was responsible for removing varietal aromatics, without some further information.

But Oskaar, keep those papers coming! ;D They are useful to build up our general knowledge database, and as you have noted, the wine guys are light-years ahead of us in quantitative research about all aspects of fermentation and production.

 

[Medsen Fey]

I ran across some interesting info at finevinewines.com. It discusses how the level of CO2 may affect flavor. They quote the same fellow from WinExpert saying the same thing about vacuum degassing. I am attempting to contact him to see if he can provide some data or references.

 

[happymondays]

Both very interesting reading and Medsen the link to de-gassing using the stirring method seems to support the method I have been told here to apply a vigorous stir for one minute intervals and de-gassing whilst bulk ageing in glass might not occur only in rackings. Be interesting to see if you get any more info off the guy.......

Regards Scott....

 

[Medsen Fey]

This article in Winemaker Magazine is written by the same fellow. He seems to talk about this quite a bit. This magazine article has more than I ever wanted to know about ways to vacuum degas a mead. If I get any response from him, I'll post it up.

 

[wayneb]

Yes - Long on technique, short on justification. I hope that he responds to your query.

 

[happymondays]

This article in Winemaker Magazine is written by the same fellow. He seems to talk about this quite a bit. This magazine article has more than I ever wanted to know about ways to vacuum degas a mead. If I get any response from him, I'll post it up.

Had a read Medsen and there is a way to convert my winesaver to fit DJ's after all, will have a look at that,

:cheers:

 

[Medsen Fey]

Mr. Vandergrift was kind enough to respond, and I have included his reply. I will try to track down the source, but if anyone has it handy, please let me know.

The information I was quoting came from a study at the University of Victoria conducted by chemistry professor J. E. (Ted) Underhill. He sampled a series of wines pre and post-vacuum and his conclusions were that even high level vacuum on a sample size of 23 litres was not detectable even after 5 minutes of exposure--a far longer time than necessary to de-gas.

Keep in mind that although you may smell some desirable aromatic compounds coming off the product it is the evolution of CO2 driving them, not the vacuum process itself. They'd be gone with the loss of CO2, vacuum or no.

The information is contained in his book, 'Making Better Wine', which, sadly, has been out of print for at least 15 years. Perhaps there is another source for this information if you wanted to follow up.

Tim Vandergrift

I still question whether rapid degassing causes greater loss of aromatic elements, compared with a slow process. Certainly, some French wine experts feel that rapid fermentation with vigorous CO2 production may be harmful to aromatic finesse, and so it may be that slow degassing may be better. I will keep looking for more data.