Stabilization, Brewing Space questions

[Lost Tyger]

From the NewBee Guide:

Potassium Metabisulfite or Sodium Metabisulfite. Potassium metabisulfite is added to wine to inhibit bacteria and yeast growth, as well as slow down oxidation. It may leave an unpleasant aftertaste in wine if the dose is too high. This chemical is also used in a water solution as an antiseptic rinse to sanitize equipment. It is identical to, but better than, Sodium Metabisulfite, because it does not add sodium to one’s diet. CAUTION: Some people, particularly asthmatics, can have a severe allergic reaction to this substance.

Use: For wine: 1/8 teaspoon (1 gram) of powder per gallon of wine provides 150 ppm free SO2. A little bit goes a long way, so be careful! Generally speaking, the target free SO2 for red wines is 20-30 ppm and 25-40 ppm for white wines.

Potassium Sorbate (stabilizer). Potassium Sorbate prevents renewed fermentation in wine that is to be bottled and/or sweetened. Use ¼ to ½ teaspoon per gallon.

My wife is concerned about the sulfites, as she does have a lot of allergies, and has a problem with headaches after drinking wine. Is Potassium Sorbate just as good? When in the process is this generally done? After bulk aging and before bottling, or when racked the last time and going into bulk aging?

Also, a question about brewing space. And when I say brewing space, I'm not really referring to the first day, making the must space, but more referring to the space you use to put your fermenters & bulk aging batches.

I've got one spare bathtub that doesn't get a lot of use that I was thinking of using. Being inside, it would be maintained at the 60-80 F range recommended. However, I also have a full basement that I was considering using. It is unfinished, and so there's no guarantee it would stay in the right temperature range. But, I do have a large space heater with a thermostat that I'm no longer using. I was thinking of building a small enclosure, large enough to hold several carboys, adding an emergency containment vessel (to contain any unforseen leaks of large amounts of must/mead/liquids), then putting the space heater in there. The thermostat on the space heater would turn it on long enough to reach a set point (say, 70 F) and then shut off, until the temperature dropped, at which point it would turn on again, enough to maintain a rougly 68-72 F. The energency containment would keep spills from shorting out the space heater. And it wouldn't be taking up any of the currently lived-in space.

Does anything sound wrong with that plan?

 

[MrMooCow]

My understanding is that it is often difficult to stabilize with just Potassium Sorbate. You may be able to make it work using it in conjunction with cold crashing. A good filter might help as well.

As for the bathroom..... I'm in the same boat. During the summer, my front (down stairs) alcove works great, but during the winter it's too cold. If you could keep the bathroom around 70, putting the carboys in a water bath would probably do the trick. Maybe block off the heater vent in the bathroom, crack open a window, etc. If I were setting up in a bathroom, I'd fill the bathtub with water about halfway up the carboy, put a fan blowing across it, and also put a dehumidifier in the bathroom. Dry air, plus wet surface, means reduced temperatures.

For the basement area.... Instead of a space heater, you might try carboy heaters. The Fermwrap Heater. If you had it in an insulated box, with the ferm wrap, you could probably keep it at fermentation temps. They sell temperature gauges that work with the ferm wrap I believe.

 

[mmclean]

Remember, for bulk ageing and long term storage, you want to keep you meads and wines around 54F.

The basement should be fine. Thats why people keep their wines in a celler.

 

[akueck]

My wife is concerned about the sulfites, as she does have a lot of allergies, and has a problem with headaches after drinking wine. Is Potassium Sorbate just as good? When in the process is this generally done? After bulk aging and before bottling, or when racked the last time and going into bulk aging?

Sorbate and sulfite are totally different chemicals with different methods of action. Sorbate is a preservative: it prevents the growth of organisms which could lead to spoilage. It will not, however, stop currently alive organisms from functioning. Sulfite does knock out the critters that are living in the product when you add it, but dissipates over time and thus offers no long-term protection. Sulfite and sorbate are therefore used in conjunction to provide both reduced activity (sulfite) and long-term stability (sorbate).

In general, these chemicals are not necessary for mead that has no residual sugar (final gravity ~0.99 or so), although sulfite is also an anti-oxidant and can help with storageability. If you have mead with residual sugar, you can reduce the yeast count by aging, fining, cold-crashing, filtration, or a combination of these. If you can sufficiently remove yeast prior to bottling, using sorbate only might be fine. IMO it would probably be fine but I don't have any data to back that up.

Also, "red wine headache" is not definitively linked to sulfites, and anecdotally is not linked at all (or is totally causative, depending on your anecdote). Can she eat dried fruit? Cranberries, apples, and tropical fruits are often heavily dosed with sulfites to preserve color.

 

[Medsen Fey]

I wouldn't use sorbate alone to stabilize a sweet mead. For one, the chances of it failing to suppress the yeast is high. Secondly, it has little action protecting against spoilage bacteria (lactic acid bacteria and others) which can easily ruin a sweet mead. Third, if Lactic acid bacteria do contaminate a batch with sorbate, they will metabolize the sorbate creating a bad geranium odor that cannot be removed (at least not without some expensive commercial winery technology).

 

[akueck]

I stand corrected. Forgot about those geraniums.

 

[Chevette Girl]

Before I really knew what I was doing, I tried a couple of times to use just potassium sorbate because I have friends who get migraines from sulphites and at least one time I tried it, it kicked back up to a bubbling ferment! Another time, I ended up with a petillant batch after bottling... it never got more than faintly carbonated but I drank it quick just in case...