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View Full Version : ?s on Campden tabs & stabalizing



Lost Tyger
05-19-2011, 01:03 PM
1. I've seen that some use Campden tablets throughout the fermentation cycles. Presumably to help crowd out wild yeasts and bad side infections? Is this considered a 'must-do' or a 'some-do?' I saw that the Campden tabs can also help fight against oxidation? Is that true, and if so, is it a good idea to use them throughout fermentation?

2. I'm looking at stabalizing before I go into backsweetening. I've seen conflicting information on the amount of Potasium Sorbate needed; I've seen 1/4 tsp per gallon and 1/2 tsp per gallon. Any recommendations?

3. I took a fancy to cold crashing, and have the 5 gallon carboy in the fridge right now for that purpose. Would this be considered an additional decent idea, or does it alter the amount of Campden and Potassium Sorbate recommended? Or is this just a terrible idea, in general?

4. BONUS - I made a newb mistake with aeration via the drill stirrer and lost a goodly amount of the must. This has left me with a lot of headspace, and I'm just now realizing the negative consequences thereof. I can add water when I do the backsweetening, and then go into bulk aging with a minimal amount of headspace. Would this address the problem, or would the 2-3 months it's been sitting with a lot of headspace have killed my product already? Scale of 1-10?

Appreciate the feedback!

Loadnabox
05-19-2011, 02:07 PM
1. I've seen that some use Campden tablets throughout the fermentation cycles. Presumably to help crowd out wild yeasts and bad side infections? Is this considered a 'must-do' or a 'some-do?' I saw that the Campden tabs can also help fight against oxidation? Is that true, and if so, is it a good idea to use them throughout fermentation?[quote]

Campden tabs should not be used during active fermentation, and in fact you should wait minimum 24 hours before pitching yeast after adding campden, as it can cause fermentation not to start, or stress the yeast causing off flavors. Tabs should only be added at the very beginning when creating your must, or at the very end when being used to stabilize.

For the most part, since honey has anti-microbial and anti-fungal properties, campden isn't needed at the beginning unless you're adding fruit and are worried about wild yeast strains or bacteria.

[quote]
3. I took a fancy to cold crashing, and have the 5 gallon carboy in the fridge right now for that purpose. Would this be considered an additional decent idea, or does it alter the amount of Campden and Potassium Sorbate recommended? Or is this just a terrible idea, in general?



Cold crashing mostly helps with fining the mead, it doesn't actually stop the yeast itself (possibly stun it or send it into hibernation is all) So the same amount of stabilization is still recommended.



4. BONUS - I made a newb mistake with aeration via the drill stirrer and lost a goodly amount of the must. This has left me with a lot of headspace, and I'm just now realizing the negative consequences thereof. I can add water when I do the backsweetening, and then go into bulk aging with a minimal amount of headspace. Would this address the problem, or would the 2-3 months it's been sitting with a lot of headspace have killed my product already? Scale of 1-10?


Don't know about ranking this on a scale, but three months would be plenty to cause oxidation. Buy some marbles or find a way to add CO2 to fill in the head space.

As for back-sweetening with water, you will reduce your ABV by a lot more. What you're really doing is watering down your wine, so you may get more "watered down" flavors.

Sorry I don't have a good answer for you on #2

Chevette Girl
05-19-2011, 02:28 PM
4. BONUS - I made a newb mistake with aeration via the drill stirrer and lost a goodly amount of the must. This has left me with a lot of headspace, and I'm just now realizing the negative consequences thereof. I can add water when I do the backsweetening, and then go into bulk aging with a minimal amount of headspace. Would this address the problem, or would the 2-3 months it's been sitting with a lot of headspace have killed my product already? Scale of 1-10?


It really depends on what stage it was at, if it had been an active fermentation in a carboy and then you had a MEA (mead eruption accident) and the airlock's been on since your last aeration, you're probably OK to leave it until you rack it and backsweeten/top it up with something. I like using white grape juice, myself, it adds a little body, a little sweetness and not much flavour. If you have a sniff and it reminds you of sherry, it's oxidized. I had one finished 3-gal batch that spent one week in a 5-gal carboy between filtrations and it did oxidize just a little (turned out it suited that wine well, but it won't always).

However, I also have a 4 gallon batch that was still fermenting just a bit when I racked it into a 5 gallon carboy and it was there for several months under airlock and it seems like I was lucky because it was still releasing enough CO2 to purge whatever oxygen was in the carboy after I racked, it smelled fine when I finally made enough make-up must to top it off...

Medsen Fey
05-19-2011, 04:59 PM
You can use Campden tablets at the beginning of fermentation, but there isn't much need for it in a traditional mead. If you are using fruit, it may be a good idea to help inhibit polyphenol oxidase and prevent browning. It may also suppress wild yeast and lactic acid bacteria when using fruit. The common wisdom says pitch the yeast after 24 hours but truthfully, I don't think it matters that much in most cases as the wine yeast we use generally tolerate sulfites pretty well.

You can add sulfite during the fermentation as well. If you get the total sulfite up to 100 ppm it will generally cause the yeast to increase glycerol production as it binds acetaldehyde (also lowering ABV a little). Some Australian winemakers favor this approach in their red wines.

After cold crashing, you still need to stabilize. For that you need both Sorbate and Sulfite. There are alternative to these such as Benzoate and Lysozyme, but these aren't as useful for a variety of reasons I won't go into here.

The dosing is most reliable if done as follows:

Sorbate - you want 200 ppm sorbate. Remember ppm is the same as mg/L so the best way to do it is by weight. To get 200 mg/L of Sorbate, you need to add 267 mg/L of potassium sorbate because 25% of the weight is potassium. There are charts which show that you can use less sorbate if your ABV is above 10% but I've seen it fail often enough that I shoot for 200 ppm now whenever I use it. At that level it is below the taste threshold (for me I can't taste it at 400 ppm).

Sulfite (aka SO2, K-Meta, Campden Tablets) - there are numerous forms. There is a thread entitled "Thorough explanation of sulfite" (http://www.gotmead.com/forum/showthread.php?t=12329&highlight=sulfite) in the Patron's area with a good link to some excellent reading on the subject. In short, you want to have a level of MOLECULAR sulfite of at leas 0.8 ppm. There are good calculators (http://www.musther.net/vinocalc.html#molso2) that can help you determine that number based on the pH and the free SO2 level. As the pH gets lower the molecular SO2 becomes a higher percentage and thus you need less sulfite. To do this properly you need a pH meter and a test kit for SO2 and both are readily available. Doing it through any other method (based on instruction on the label, or adding a wrote number of campden tablets) is essential a guess and you hope you are right.

If you have to guess, 1 Campden tablet per gallon (440 mg) produces about 75 ppm Total SO2, and roughly half of that will be Free SO2. This is why I typically suggest using at least 1.5 Campden tablets per gallon. That gives more like 100 ppm total and 50 ppm Free SO2 - at least that is what we sort of hope/expect. How much actually gets bound and how much remains free will vary depending on things like how much sugar and how much gluconolactone are present. At 50 ppm as long as your pH is 3.6 or lower, you'll have enough Molecular SO2. If your pH is higher, you'll need more sulfite.

Honey can bind a lot of SO2 and even though you think you have enough, if you are adding honey to sweeten it may not be enough. If you have the SO2 test kit, measure after backsweetening, and you'll be shocked at how much more K-Meta you may need sometimes.

We need more data on SO2 binding by honey musts and meads and I hope to be able to contribute something on this later this summer.

I hope this makes it a little easier to understand.

tweak'e
05-19-2011, 05:44 PM
the cold crashing can help. it will only pause the yeast but that can mean it stops producing alcohol roughly where you want it to and gives it time to settle so the mead can be racked off the yeast.
much easier to stabilize a small amount of yeast than a big lot of yeast.