Potassium Metabisulphite

Used to prevent refermentation in wines prior to sweetening and/or bottling. Sanitizer - use 2 oz per 1 gallon of water. Antioxidant and bactericide -
use 1/4 teaspoon to 6 gallons. Dissolve sulphite in warm water before adding.

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9/4/2006 -- If I am making wine from concentrate, is it recomended I add the bentonite at the pre-fermentation stage?

Secondly, should I add yeast nutrients at the same time I add the yeast?

Thirdly, should an acid blend always be added to help in the fermentation period?

Lastly, what should the brix level be at so that I know how much water to add to the concentrate?

Response From The Home Brew Store Dot Com: Several manufacturers of 28-day or 6-week wine kits recommend adding the bentonite in pre-fermentation. However, I have found that I get a better result if I add the bentonite in the secondary.

You should dissolve the yeast nutrient in a small amount of warm water, and add it to the must prior to pitching the yeast.

Acid blend is not always necessary. If you are working from an established recipe, and it calls for some, then by all means add it. However, if you are building your own recipe or "winging it", you should do an acid test to determine if additional acid over and above that contained in the fruit is necessary.

The original specific gravity for a sweet wine should be around 1.120. For a dry wine, right around 1.090-1.095 works. I'm not certain what the brix equivalent is for those SGs.

7/5/2006 -- We have a recipe for making orange wine. It calls for wine yeast, grape tannin, and yeast nutrient. Which of your products do you suggest? And what quantities?

Response From The Home Brew Store Dot Com: For the grape tannin, we only have one choice: Stock number 7390 is powdered tannin from actual grape skins.

For the yeast nutrient, we have two options. Our basic nutrient (stock number 7357) is a compound called diammonium phosphate. It's a lab-produced clone of the chemical compound in dead yeast cells and works very well. We also have a product called servomyces (stock number WLN3200). This is produced by Dr. Chris White of White Labs - the largest producer of liquid brewing yeasts in the USA. Either of these products works very well, although I would probably recommend the first one if you are running a test batch.

For yeast, I highly recommend the Lalvin 71B-1122 strain (stock number 4919). This yeast works very well with fresh fruits and fruit juices, and is excellent for lighter colored fruits such as peaches, pears, apples, and citrus.

As for quantities of each ingredient, that depends on the batch size. Grape tannin is only used in very small amounts (roughly 1/8 tsp per gallon) so the smallest sized package would be plenty. The yeast nutrient requires between 1/2 and 1 tsp per gallon. There are about 2 tablespoons in a 2oz bag. One packet of yeast is sufficient for anywhere from 1 to 6 gallons.

6/13/2006 -- I have seen manufacturers using potassium metababisulphite in products like coconut milk. What I would like to know is whether or not using this product on a regular basis is bad for your intestines and other organs of the body. Also, would regular use of this lead to cancer?

Response From The Home Brew Store Dot Com: Small amounts of sulfites can cause adverse reactions in people with sulfite allergies and/or asthma.

The following is from a study published by the International Programme on Chemical Safety (IPCS):

"While sulfiting agents can interact with DNA and may induce mutations in bacteria, in vivo mutagenicity studies in mammals were negative, as were long-term carcinogenicity studies on potassium and sodium metabisulfite in mice and rats, respectively. Long-term anti 3-generation studies in rats receiving metabisulfite in the diet with added thiamine showed a no-effect level of 0.125% sodium metabisulfite (equivalent to 70 mg SO2/kg.b.w./day)."

While I cannot guarantee that there are no adverse effects, I can tell you that the amounts recommended for home brewing are well within the limits cited by IPCS.

2/24/2006 -- I think I might have made a mistake and added the wrong yeast packet into a 5 gallon batch of prickly pear mead I am making that might result in a much higher alcohol content than what I intended (16-18% instead of 12-14%) and was wondering what I could do to stop fermentation early to get the desired alcohol level. I have potassium sorbate but am not sure how much to add or if it will stop the fermentation after I rack it, if you have any suggestions I would very much appreciate it.

Response From The Home Brew Store Dot Com: Unfortunately there is nothing on the market that will stop an active fermentation. Your best bet is in the lag period between primary and secondary fermentation. When the bubbling in the airlock slows to an almost imperceptible level (two to three weeks usually), immediately rack the mead into a clean and sterile fermenter and add the potassium sorbate. A good rule of thumb is to dissolve a half-teaspoon of crystals per gallon of mead in about a pint of boiling water and add it to the carboy before siphoning the mead in on top of it. Let it sit 24 hours. If it starts bubbling again, there's nothing to do except let it run its course.

If you cannot succeed in stopping the active ferment, the alternative is to blend. Allow the mead to finish completely - take it all the way to alcohol tolerance for the yeast so the yeast will die. Add the potassium sorbate as stated above. Then mix up a gallon of unfermented mead with the same ingredients, and blend it into the finished mead. This will dilute the alcohol without diluting the flavor.

12/30/2005 -- Potassium & Sodium Metabisulphite
How & When & Why do I use them ??

Response From The Home Brew Store Dot Com: Both types of metabisulphite serve two three purposes. First, they can be used to kill of wild yeasts and other organisms in natural fruit prior to fermentation. Second, they are used post fermentation to stabilize wines and meads prior to sweetening in order to prevent a refermentation in the bottle. Finally, they act as a preservative/anti-oxidant in the finished wine/mead.

How you use them is simple. For pre-fermentation, I generally recommend campden tablets, which are a specific form of metabisulphite designed for this role. You would use 1 tablet for each 2 gallons of liquid, crush up the tablet, and sprinkle it over the crushed fruit. Allow it to sit 48 hours covered, then vent for 24 hours before moving on to primary fermentation.

As a stabilizer and/or preservative, you would use either potassium or sodium metabisulphite in its crystal form. You would dissolve about a half-teaspoon of crystals in boiling water for each gallon of wine/mead - a pint of water works fine for up to 6 gallons. Rack the wine/mead into a clean carboy after secondary fermentation, add the sulphite solution, and let sit for 24-48 hours before sweetening or bottling.

If you are allergic to sulphites, or just prefer not to use them in your wines/meads, you can use potassium sorbate as a stabilizer, and ascorbic acid as an anti-oxidant. There is no good substitute for campden tablets in pre-fermentation, but I have been able to mitigate that problem by initiating a sealed yeast starter about a week prior to brewing, and pitching the then-active starter right into the fresh fruit. The active fermentation generally overcomes any wild yeast in the fruit.

Note that even though sukphites are stabilizers, they will not stop an active fermentation.

11/21/2005 -- I'm making a batch of Merlot from a kit. I am missing my packet of metabisulphite. I may have added it already as a mistake. I just racked my wine the first time and the next time calls for the metabisulphite. Is there anything I can do? Should I add another packet when I rack the wine again? What does it do?

Response From The Home Brew Store Dot Com: First of all, did your wine ferment? If it did, you can rest assured that you did not add the metabisulphite by mistake. Metabisulphite is a stabilizer, and is added to finished wine to prevent refermentation in the bottle. Essentially, it renders residual yeast in the wine unable to process new sugars. If you checked your specific gravities, and the numbers match (or come close) to those given in the directions, then you don't have metabisulphites in the wine.

That being said, there are two things you can do. metabisulphite is available separately in both sodium and potassium form. You can purchase a packet separately, and add the recommended amount for the batch of wine you are making (usually a one to two teaspoons for a 6-gallon batch.)

Your second option is to leave it out altogether. Sulphites in too high a concentration can lend a nasty taste and/or odor to finished wine, and some people are even allergic.

You probably have a packet of potassium sorbate, which will stabilize your wine as well. You can add a touch of ascorbic acid as an anti-oxidant. After that, proper storage of your wine will assure proper aging, and help prevent refermentation.

6/1/2005 -- Can you tell me the average concentration of potassium in merlot and/or other dry red wines?

Response From The Home Brew Store Dot Com: It's difficult to breakout the potassium content from the base wine for two reasons. First, there is potassium resident in the grapes prior to the winemaking process. Second, the amount of potassium added during winemaking is based on the ppm of sulphur dioxide (SO2) compounds in the metabisulphite solution rather than on the ppm of the potassium.

That being said, the concentration of potassium in grapevine leafstems is between 1% and 2.5%. The resulting concentration in grape juice from those healthy vines would be about 15 to 20 ppm. During the winemaking process, the addition of potassium in both the sterilization process (pot. mbsulph.) and the stabilization process (pot. sorbate) increases the innate concentration by 25 to 40 ppm.

3/19/2005 -- I noticed there are a lot of different choices of cleaning agents. What's the basic difference between a "cleanser" and a "sterilizer"?

Response From The Home Brew Store Dot Com: The basic difference between a cleanser and a sterilizer is that a cleanser is designed to remove dirt, grime, stains, etc. while a sanitizer is designed to kill bacteria. The important thing to remember in brewing is that your equipment needs to be both CLEAN and STERILE; so in some cases, both agents may be required.

Cleansers typically include some kind of soap or detergent agent. Tri-sodium phosphate is common in some of the stronger agents, while other (less caustic) chemicals show up in products like oxy-clean, washing soda, powder brew wash, etc. For the most part, there is some caustic activity when using these products since they are designed to break down dirt and either eliminate it or make it easier to scrub off. The single most important thing to remember is that most of these products need to be rinsed thoroughly in order to avoid having them affect the flavor, fermentation, or carbonation of your beverages.

Sanitizers are a different thing altogether. Some sanitizing agents may include a cleanser (such as the ever-popular no-rinse cleanser), while others are strictly anti-bacterials. In most cases, sanitizers will not attack stains or built-up dirt/grime, although I've found that the hot water I use with sanitizers will cause some of that to loosen up. Some sanitizers kill on contact while others require a set period of time (usually noted on the label). The other things to remember about sanitizers is that some of them leave a residue, or may be detrimental to the material you are using them on. For instance, household bleach is a popular sanitizer for brewers. However, bleach tends to leave a mild residue on the inside of glass carboys that can build up over time. Also, bleach will cause a caustic reaction with stainless steel, and can really mess up the inside of your cornie kegs with frequent exposure. Iodophor (or any other iodine based sanitizer) will stain plastic buckets after one or two uses.

Bottom line - if it looks dirty or stained, use a cleanser and a scrub brush to get it clean. No matter what it looks like, use a sanitizer to get it sterile.

7/29/2004 -- What are the other chemicals and tablets that you would recommend for us if there is a need of them?

Response From The Home Brew Store Dot Com: If you are starting with fresh fruit (rather than canned juices), I would recommend campden tablets. Allowing the juiced fruits to sit in a campden solution for 24 hours will kill off any wild yeasts that could spoil the ferment.

For honey or for some high pectin fruits (such as strawberries or plums), I would recommend yeast energizer for a quick start to the ferment.

I always recommend yeast nutrient, which is sort of a vitamin pill for the yeast. It helps to sustain the yeast through the critical first few weeks of the ferment cycle.

I recommend pectic enzyme for high pectin fruits as well. This helps break down the pectins and avoid hazy wine.

Add a touch of grape tannin for wines made from fruits with low tannic acid.

Acid blend and/or the various types of acid should be added cautiously to balance the tartness in the wines and assist in a strong ferment. Certain fruits are high in one type of acid or another, so blindly adding acid blend without knowing the acid balance in the fruit you are using is not a good idea.

When the ferment is completed, a stabilizer such as potassium sorbate should be added prior to sweetening the wine, in order to prevent refermentation in the bottle. Also, some sort of sulphite is important for long-term storage to prevent spoilage and/or oxidation.

7/28/2004 -- Hey, it's been 3 days since I mixed up my batch of wine and the only thing I have done different from the instructions on the package was when I rehydrated the yeast I put a little bit of sugar in the warm water and left it in there for about 20 minutes instead of 15... but it's not fermenting and it's actually sucking water back up the hose... should I pour it out and start over????

Response From The Home Brew Store Dot Com: Never pour out a batch of homebrew until all options for fixing a problem have been exhausted. Many times, it's a simple fix. In this case, there are a couple of problems that may be the cause.

The first possibility is that the fruit juice you are using may have preservatives. You didn't specify if you used fresh fruit, juice from a homebrew store, or other commercial juice. Whenever you use commercial juice (from somewhere other than a homebrew shop), check the label for the words "potassium", "sulphite", "sorbate", or "to preserve freshness". Any of these indicate that a preservative has been added. Overcoming preservative is a long and arduous process, and if you write back and tell me that's the problem, I'll send a complete answer.

Another likely problem is that the yeast was no longer viable. Dry yeasts usually last about 3 to 6 months in room temperatures, up to a year or more when refrigerated. However, yeast is tricky and these timeframes are just estimates. Humidity, changes in temp, and other factors can shorten yeast life. If you have a slow start or a stuck ferment, always try a new yeast starter with a fresh packet of yeast.

A third factor could be residual cleanser or sanitizer on the equipment. In this case, thoroughly sterilize and rinse a new fermenter. Siphon the liquid into the new fermenter, being sure to oxygenate it thoroughly. Then start over with a fresh yeast starter.

10/14/2003 -- I am making scuppernong wine and it has a vinegary taste to it. Any suggestions as to why this happened and what I can do to eliminate the vinegary taste?

Response From The Home Brew Store Dot Com: There are a number of different reasons for why it would have a vinegary taste. First of all, do you have any sort of milky or egg-whitish film floating on top of the wine? If so, this is called a "mother of vinegar", and it indicates that the wine has actually turned. It's easy to identify because it's a little different from the meringue-like foam or carbonation-like foam layer that forms during fermentation, and it never goes away. The best thing to do in that case is to cultivate the vinegar, bottle it, and use it for cooking or as gifts. Homemade vinegar is very good.

If there is no "mother" floating on top, then the taste can be for a number of other reasons. The most common is that some sort of bacteria escaped the sanitation process and has soured the wine. Another could be that a wild yeast strain got in before your cultured yeast got active (in some cases, people prefer to use the natural yeasts that reside on the grape skins... which is sort of a crap-shoot for flavor.) Wild yeasts tend to have a more vinegary or cidery flavor. Another cause could be that all the sugar was eaten up in the fermentation process. Scuppernong is a sourish grape to begin with, so it doesn't make a good dry wine.

In any of these cases, you can use a combination of refermentation, resweetening, and aging to mellow the flavor. Start by checking the viability of the current yeast. If your wine is still in the fermenter, dissolve a few tablespoons of sugar in warm water and add it to the fermenter. If you notice refermentation, then your yeast simply used up all the original sugar. At this point, you can continue to add sugar in small amounts until the yeast dies, or you can rack your wine into a new container and add a stabilizer (such as potassium sorbate) to prevent refermentation. Once you have done one of those things, then you can sweeten the wine to taste. Adding a touch of ascorbic acid (an anti-oxidant) can help.

Finally, after complete fermentation and sweetening, age is your friend. Let the wine age in the bottle (on its side) for at least 6 months before tasting again. You should notice the flavor mellowing a bit. I usually put 1/4 of my batch in a dark, cool place and leave it for two to three years, and those wind up being my best bottles.

If after 6 months to a year in the bottle, the vinegary taste is still strong, don't throw the wine away. Scuppernong grapes add an interesting flavor to foods, and the wine can be used in place of wine or cooking sherry in food recipes.

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