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auto
04-19-2007, 09:00 AM
New to Mead game, like you didn't know ;)

Short fermentation, 1.5 weeks, all fermentation activity has stopped. I assume I am ok, I am just wondering why the fermentation was so quick when the previous batches went on for 3 or so weeks.

O.G. 1.08
F.G 1.00 or real close

Utilized a Red Star Champagne Yeast.

Any suggestions?

Oskaar
04-19-2007, 10:04 AM
Exact recipe please. We can't really dial it in without all the ingredients in front of us.

Cheers,

Oskaar

auto
04-19-2007, 10:16 AM
Sorry about that.

5.5 lbs honey
2 gal water
24oz pumpkin
1 tspn spices
twist of orange peel
Red Star Champagne yeast
Fermax

I should add this is extremely dry (duh)I would like it a little sweeter.

wayneb
04-19-2007, 01:53 PM
Well, you've answered your own question. "Extremely dry" means that it isn't stuck. It is definitely finished fermenting. I don't know the net effect of the pumpkin since I don't know the %sugar by volume that it brings to the mix, but I suspect that it is less than your honey/water ratio to begin with.

The OG that you measured appears to be consistent with the honey/water ratio that you mixed before adding the pumpkin, and at only 1.080, you're more closely aligned with a high gravity beer wort than a typical mead must - you have a potential ABV of only around 10% there. So the combo of this honey/water ratio, a relatively aggressive yeast strain like Red Star Champagne, and a nice dose of nutrients by way of the Fermax and the stuff the pumpkin contributes, and I'd say you 've ended up with exactly what you should expect!

Now if you'd like it a little sweeter you're gonna have to sulfite and sorbate it. With a typical alcohol tolerance around 16% for your chosen yeast, if you add any more sugar to the mix, even if you were to cold crash it and rack several times, I'd still expect fermentation to take off again some day if you don't kill off the yeast first.

auto
04-19-2007, 02:22 PM
Wayne, Thanks, sort of wanted to bounce the ideas off the more experienced. How much sorbate and sulfite should I add? Should I also add more yeast?

wayneb
04-19-2007, 03:17 PM
If you're looking to sweeten up the batch, then you don't want any more yeast. You actually want to get rid of the yeast that is still present in the mead. I generally try to use as little sulfite as possible, so the most I've ever added has been 1/4 tsp of potassium metabisulfite per gallon. That is usually enough in most finished meads to produce enough free SO2 gas to kill remaining yeast cells, but the amount of free SO2 that is actually produced is a function of the pH of the must, so this is for a must that hasn't been pH adjusted. For reference, the amount of free SO2 produced in a pH 3.0 must is 10 times that produced in a pH 4.0 must, for the same amount of KMETA added!

For sorbate, I use a "heaping" 1/4 tsp of potassium sorbate per gallon. That's something less than 1/2 tsp per gallon, which is the "usual" recommended dose to stabilize wine, but I prefer to minimize the amount of chemicals that I add to anything that I brew.

You can choose to leave all sulfites out, and just stabilize with potassium sorbate, but in a mead that is to be backsweetened, I think the one-two punch of sulfite plus sorbate is a more sure control. That said, I have to admit that I rarely sulfite anything any more. I make due with sorbate only, but only after I've spent several rackings AFTER the mead initially clears (and several months of patient waiting) making sure that virtually all the active yeast cells have precipitated out before I bottle.

So, after you've sulfited (and allowed the must to sit under an airlock for a few days to allow the free SO2 to outgas) and then sorbated, you can backsweeten with additional honey to taste, and then bottle.

Oskaar
04-20-2007, 12:10 AM
Funny you mentioned SO2. We just did an interesting lab excercise on SO2 in my Wine Production class. Here's some excerpts:

In grape wine sulfur dioxide can block chemical oxidation of phenolic compounds by binding to oxygen radicals. Its reaction rate with molecular oxygen is so slow under wine production conditions that it will not directly block generation of oxygen radicals in the first place. It also has a perhaps more important role in inhibiting enzymatic oxidation reactions.

Grapes possess an enzyme known as polyphenol oxidase, PPO. PPO reacts with molecular oxygen, water and phenolic compounds to produce an oxidized phenolic compound and hydrogen peroxide. The hydrogen peroxide can then react with other components in the juice or wine. PPO functions in defense against microbial attack and is one of the most important enzymes of the vine chemical warfare program. Hydrogen peroxide is the goal of the catalysis as this compound has strong antimicrobial effects.

It is not clear if the oxidized phenolic compounds are also inhibitory. PPO is released to the must or juice upon crushing of the berries, so is present and active in fermentation. Many oxidized phenolic compounds are undesirable as is the production of hydrogen peroxide. Yeast possess an enzyme called catalase which degrades hydrogen peroxide so are not inhibited by the levels of this compound produced in the must or juice. However its effects on the chemical composition of the wine, and inducement of aldehyde and off-color (brown, orange, pink) formation are undesirable.

Molecular oxygen serves as a micronutrient for many organisms, required for the biosynthesis or degradation of many compounds. PPO successfully competes with the microbes present in wine for O2. Oxygen is required by the yeast for optimal ethanol tolerance (this is why we aerate in order to get O2 into the must for the yeast so they can synthesize sterols to strengthen the cell walls and have a higher ETOH tolerance), if PPO activity is unchecked, the yeast may be in a nutrient deficient situation (in this case O2 as a nutrient). This is an additional reason to add SO2 in grape musts. It is not clear at the molecular level exactly how SO2 is able to inhibit PPO activity.

It is important to note that sulfur dioxide levels are affected by both pH and the fact that it is bound by many different substances in wine including tannins, thiamin, and certain oxidative enzymes such as polyphenol oxidase. Sulfur dioxide binds with other substances such as aldehydes and ketones, and will reduce over time due to chemical volatility. It is this affinity to bind and react with other substances in wine that necessitates close monitoring of the levels of free (unbound) sulfur dioxide before, during and after fermentation has been completed. Also consider that free-run juice such as used in making white wines where the grapes are pressed and only the juice and no pulp is used will have less suspended material for the SO2 to bind with, than in red wine where there will be considerable material from the pulp, seeds, skin, etc. So that is also a factor to consider in both the influence of pH on the bound and unbound (free) levels of SO2.

I have a couple of tables that I'll see about posting that help determine where to be with your dosages in red and white wine. Other factors such as temperature, containers (stainless, barrel, glass etc), and the turbidity of the juice all play a role.

Hope that helps,

Oskaar

Sources:

Texts:
Bisson, L., 2005. VEN 124 Wine Production for Distance Learners, Lesson 5: Juice and Must Treatments and Additions Topic 5.2: Juice Additions

Boulton, R., V. Singleton, L. Bisson, and R. Kunkee. 1996. Principles and Practice of Winemaking. Chapman and Hall. New York

Peynaud, Emile, 1984. Knowing and Making Wine, (English Translation) John Wiley and Sons, Inc. USA

Journal Articles:
Baldwin, G., Basic Effects of Sulfur Dioxide on Yeast Growth. American Journal of Enology & Viticulture Volume 2: 4553. 1951

Cocolin, L., and D.A. Mills Wine Yeast Inhibition by Sulfur Dioxide: A Comparison of Culture-Dependent and Independent Methods. Am. J. Enol. Vit. 54: 125 130. 2003

Other Articles:
Delteil, D., Enological yeast effect on the sulfur dioxide content and management in wines. Institut Cooperatif du Vin, 1 4 1992

akueck
04-20-2007, 02:03 AM
Is the PPO enzyme specific to grapes or do other fruits also have it?

Pretty cool that grapes are designed to kill off bugs....and bugs are designed to thwart grapey peroxide death squads. Evolution is funny. :icon_cyclops:

Oskaar
04-20-2007, 12:03 PM
Not sure about PPO existing in honey yet. I'm in touch with a couple of apiculturalists associated with the IMA in order to research what anti-oxidative enzymes there are in honey, and how they function in honey. It may be that honey has it's own enzyme analogous to PPO, or even a group of enzymes that function in that manner. So this could be a gateway into a serious research project on honey that could draw some scholarly attention to meadmaking.

Cheers,

Oskaar

wayneb
04-20-2007, 12:49 PM
Very interesting. It does call into question the applicability of KMETA in meadmaking. If the principal antioxidative effect is the check on PPO, and if there is no analog to PPO in mead must, then the only thing KMETA will do for you is to shut down yeast metabolism. You can achieve the same effect simply by moderately warming the mead must (up to 105-110F for 45 mins), which will cause yeast to go dormant and precipitate out.

If memory serves, in honey glucose oxidase acts on glucose in the presence of H2O to produce gluconic acid and H2O2, right? I wonder if the SO2 acts to inhibit the action of glucose oxidase in honey in the same way that it throttles PPO in wine musts? (My speculation only... any real information would be VERY welcome!!)

Oskaar
04-20-2007, 01:33 PM
From what I've seen in the references and labwork so far sulfites are applicable even if there is no analogous PPO anti-oxidative/enzymatic activity in mead for several reasons.

Anti-yeast - prevents further yeast driven fermentation or spoilage yeast

Antibacterial - spoilage bacteria, lactic-acid bacteria

Antienzymatic - destroys various oxidases (PPO included) which catalyze oxidation reactions

Antioxidative - strong reducing power, hoards oxygen and prevents browning and yellowing

Taste improvement - reacts with and blocks acetaldehyde which in turn preseves freshness of aroma

It's also interesting to note that sulfur is not a contemporary addition to winemaking/fermentation and was practiced by the Romans and Greeks in their winemaking.

Cheers,

Oskaar

wayneb
04-20-2007, 03:15 PM
From what I've seen in the references and labwork so far sulfites are applicable even if there is no analogous PPO anti-oxidative/enzymatic activity in mead for several reasons.

Anti-yeast - prevents further yeast driven fermentation or spoilage yeast

Antibacterial - spoilage bacteria, lactic-acid bacteria

Antienzymatic - destroys various oxidases (PPO included) which catalyze oxidation reactions

Antioxidative - strong reducing power, hoards oxygen and prevents browning and yellowing

Taste improvement - reacts with and blocks acetaldehyde which in turn preseves freshness of aroma

It's also interesting to note that sulfur is not a contemporary addition to winemaking/fermentation and was practiced by the Romans and Greeks in their winemaking.

Cheers,

Oskaar




I didn't mean to suggest that I am anti-KMETA. But I have to admit that I use it much less frequently to prepare finished mead for bottling than I used to in years past, and I haven't noted a significant difference in the keeping ability of my meads as a result. It just got me wondering exactly what the SO2 actually does for us in mead.

I certainly can see the benefits of a strong antioxidant presence, and that alone (when considered with the fact that sulphur has been used throughout recorded history as an antiseptic in wine storage vessels, so it as you noted isn't a "modern" adulteration) is sufficient to warrant its use. I'm still curious about what, if any, enzymes should be neutralized in fully fermented mead. Also, do you know, is much acetaldehyde formed in mead during fermentation? Actually, I guess I should say is there a difference in the amount of unconverted acetaldehyde left in mead vs that left over in wine during the process of fermentation?

Chimerix
04-20-2007, 03:49 PM
KMETA?
Kids Making Educational Television Avoidances?
I thought they lost their Supreme Court appeal.

Oskaar
04-20-2007, 05:24 PM
I didn't mean to suggest that I am anti-KMETA. But I have to admit that I use it much less frequently to prepare finished mead for bottling than I used to in years past, and I haven't noted a significant difference in the keeping ability of my meads as a result. It just got me wondering exactly what the SO2 actually does for us in mead.

I certainly can see the benefits of a strong antioxidant presence, and that alone (when considered with the fact that sulphur has been used throughout recorded history as an antiseptic in wine storage vessels, so it as you noted isn't a "modern" adulteration) is sufficient to warrant its use. I'm still curious about what, if any, enzymes should be neutralized in fully fermented mead. Also, do you know, is much acetaldehyde formed in mead during fermentation? Actually, I guess I should say is there a difference in the amount of unconverted acetaldehyde left in mead vs that left over in wine during the process of fermentation?




Dude, no worries at all!

I was just putting up a list of things that sulfites do that are actually beneficial in wine and/or mead. Some of these things need to be researched in greater detail in order to see just what benefit/lack thereof sulfites may provide in mead. The preservative (anti-oxidative), anti-bacterial, anti-yeast, are all pretty well established in my opinion. Things like the PPO suppression and aldehydes, ketones, etc are all things that I haven't seen any serious research on. I think the issue of aldehydes is common in wine and mead, but, I don't know what levels we're talking about.

That's why I'm trying to spin up some interest at various higher learning, and commercial research facilities to see if we can get a research project funded. This parallels issues of malo-lactic fermentation and rapid-aging experiments. The reason I've cited my sources in the sulfites post was to visualize just how much research has been done on it's effects in wine. There would be 0 sources to cite on meads that I know of. That list in the sulfites post was also just for the brief number of paragraphs of information that I posted. Just one of the texts that I'm reading had two pages, single spaced, double columns worth of references on sulfites in wine. If we could get half of that kind of interest and research generated for sulfites in mead we'd be on our way to some real, genuine industry intrest.

Cheers,

Oskaar