View Full Version : how to backsweet ?

03-03-2010, 10:27 AM
I have another small batch that finished fermenting but does not clear completely. It was racked and has no new lees, I did add some cognac. I don't really care about it clearing or not, but it tastes like I put a lot of clove in it :p and it's completely dry. Is it wise to backsweeten it with sugar or something else, or do I have to use sulfites to prevent reactivating the yeast? If so, how much per liter?

Now it's in the frige, hopefully to clear it up at least a tiny bit.

03-03-2010, 12:09 PM
I would use sulfites, and perhaps a little potassium sorbate as well, unless you are sure that there are no active yeast remaining in there. In typical meads that finish around pH 3.5, net free SO2 level of 50 ppm will usually inhibit spoilage organisms and with a dose of sorbate will ensure that fermentation will not restart. 50 ppm is equivalent to 50 mg/l, so you need a net of 50 mg of "free" SO2 per liter. However, it is not as simple as just adding that amount. Some of the sulfite will bind with other compounds in the mead, and so will not be available as SO2 to work as a protective agent. It is an OK rule of thumb to assume that the first 50 ppm SO2 of the first sulfite that you add will be bound. So, you want to add a total of 100 ppm if this is your first addition. Given that potassium metabisulfite provides 57% by weight of SO2, so if you are using the potassium powder, then you should add 100/0.57, or 175 mg/l of the powder.

There are sulfite test kits that can measure the amount of total SO2 in a mead or a white wine, but they can be fooled by some of the other compounds in red fruit wines and meads, so I usually just add based on the rule of thumb that I've given you above. NOTE: If your mead's pH is significantly different than 3.5, you will have to make some other adjustments since the amount of free SO2 relates to the total molecular SO2 level (which is the "real" protective form of the chemical) as a function of pH.

Oh, and if I were to backsweeten, I'd use honey. It is a mead, after all! ;)

Dan McFeeley
03-03-2010, 12:16 PM
I'd add that it's a good idea to wait for the mead to clear, else you're taking the risk of the dormant yeasts waking up when you give them more sugar to chew on. Sulfite and potassium sorbate will help, but it's best to eliminate all risk factors.

You said it's dry -- did you take a gravity reading?


03-03-2010, 12:47 PM
gravity did not change over a period of one month, whilst my other batches do change. So I'm quite sure it is stable.

I have sulfite (campden) and sorbate (to backsweeten). But after reading here above, I'm even more confused :-).

How much of both would I have to use for a 2 liter batch ?

03-03-2010, 12:58 PM
Small batch, eh? For two liters, adding 175 mg/l means adding a total of 350 mg of potassium metabisulphite powder, or the equivalent fraction of a campden tablet. That's slightly more than 1/4 gram. I hope you have an accurate scale! ;)

I don't remember what the proper per liter addition of sorbate should be, so I recommend following the instructions that came with your sorbate, and measuring out an appropriate fraction. Most instructions for homebrewers usually refer to how much needs to be added to a 19 liter batch. You'll need correspondingly less.

03-03-2010, 01:24 PM
thanx mate !

I just bought a scale that does 0.1 grams.

As for the sorbate, I guess trial and error will have to work :p

I wish you guys were here because my GF thinks this batch is utterly vomit-inducing, while I think it's just dry and clove-ish :p
I need a connaisseur to try it :D

I had the batch in the frige and the cap came off it under pressure, but nothing changed in the readings... can that be because it's slightly sparkling ?

03-03-2010, 01:41 PM
AH! Courtesy of our friends at the British Columbia Amateur Winemakers Association, I found the sorbate addition data online! Here are the amounts of sorbate to add, based upon alcohol concentration:

Assuming that proper levels of free SO2 are maintained and the pH's are within the desired ranges, sorbate additions can be determined by the estimated alcohol of the wine. The following table is based upon the percentage of alcohol in the wine:
% alcohol sorbate addition
10 0.20 g/l
11 0.17 g/l
12 0.135 g/l
13 0.10 g/l
14 0.07 g/l

And yes, residual CO2 coming out of solution in a slightly sparkling must can pressurize your container enough to pop a stopper. But be doubly sure that the fermentation has indeed completely stopped before you add your sulfite and sorbate, or you may find that you still get re-fermentation!

03-03-2010, 02:58 PM
After backsweetening with honey, I have had a haze apear in a mead that had already fermented out (12%) and dropped brilliantly clear. Wondering how long I need to wait now, to have it drop clear again?

Alternatively, how much time do I need to figure in, to let everything age out and integrate the lately-added "new" honey taste into the mead, have now back-sweetened, before I carry on to bottling, and drinking the mead? Haven't I got to figure that those meta bisulfite and Na sorbate additions that I was careful to add right before backsweetening, are just going to arrest the natural aging processes in their tracks, so that further aging might be kind of pointless?

03-03-2010, 03:08 PM
What would make you think those additives might arrest the aging process? They just stop the yeast from fermenting the new sugar, they don't (as far as I know) prevent any of the chemical reactions involved in aging other than that sulfites are anti-oxidants, so they might slow that part of aging down a little (not necessarily a bad thing from what I've read).

03-03-2010, 03:39 PM
As AToE says, the addition of some sulfite to a mead will provide some antioxidant effect, but that will fade with time as the SO2 eventually dissipates. Sorbate doesn't appreciably affect aging unless you use too much. With time potassium sorbate will change to a chemical that can taste a bit like bubblegum to some people, but at the dosages commonly used to stabilize wines and meads it is virtually undetectable.

The melding of honey used in backsweetening into the finished mead usually takes on the order of a few months, depending on how much you add. Not all the chemical reactions that are involved in the process are well characterized, but some micro-oxidation of the sugars, as well as binding of proteins with tannins and/or other phenolics, will occur. Those will change the flavor profile and help to promote clearing because the bound proteins eventually precipitate out of solution more easily than proteins that haven't been bound.

03-03-2010, 04:53 PM
I thought sulfate was to stop fermentation...

03-03-2010, 06:31 PM
Sulfites added at the 50 to 100 ppm concentration will prevent dormant yeast cells from re-activating should changes in environmental conditions occur that would otherwise stimulate them into more fermentation (a warm up, or mixing lees back up into the must, as examples). But sulfites will not stop an active fermentation in the dosages we usually use in mead and winemaking. Some strains of yeast can tolerate sulfite levels in excess of 350 ppm, and sulfites are easily smelled and tasted at that concentration. You don't want to be adding that much sulfite to your must, or its flavour will be changed.

03-04-2010, 12:42 PM
oh ok

it's still sitting in the frige but it gets even more clouded ...

03-11-2010, 11:17 AM
i's clear !

I've botteled, but its just not enough for 3 bottles, so I'll top em off with more apple juice.
I think I added slightly to much sulfite, but It 'll age out :p

and now I hope I don't hear a big bang :p