A word of advice on sterilization

[Carles]

Dear folks,

I am a somewhat experienced beer homebrewer, but I have never attempted to make wine. Recently, a friend gifted with a large amount of grapes which I don't think I'll be able to eat them all, so an idea quickly came to my mind: to turn them into wine. I have tried to read a bit of literature on the matter, namely "The Joy of Home Winemaking", in which I discovered that as in this forum fruit wines are quite popular, I will definitely try that some day. However, there are some questions that as a beer homebrewer sound surprising, and probably is no big deal, but I just wanted to check with you in case I missed something.

Overall, everything seems more or less like brewing beer, the only difference is boiling. As most of you are probably aware, when brewing beer you boil the most for an hour and a half, not only for the hops to be incorporated into the beer, but also for sterilization. The boiling kills any living thing on the most ensuring that when you add the yeast it will have no competition. However, it seems that in winemaking this step does not occur, which makes me wonder what sterilization alternative is used. In "The Joy of Home Wine Making" the author uses Campden tablets, which being chemical I'd prefer to steer away from it, but maybe I'm just being too paranoid. I have searched the forum and I read about filtration systems too, but I didn't grasped all of it. Finally, I can keep using the old ways and boil the most, but I am afraid I can just ruin it.

Thanks a lot and forgive me if this question has already been answered and I have made a poor use of the search function.

Best,

Carles

 

[Ohio Bob]

Sterilization is not needed because CO2 is generated during fermentation. That along with a low pH, 2.9-3.9, keeps any bacteria from spoiling the wine. Once the wine achieves 11% ABV, combined with the pH, that will protect the wine.

 

[winemaker81]

DO NOT boil the must -- you will ruin it. Trust what's in The Joy of Home Wine Making.

As I said in your intro post, most of what you know about beer making does not apply. You are jumping into a completely different world.

There is no "sterilization" in winemaking, it's "sanitizing". Wine is generally at least 10% ABV and it's quite acidic, so most microbial life cannot survive in this hostile environment. These posts on sanitation in wine and sanitizing during winemaking describe my understanding and what I do, and may help you.

Sulfite, in the form of Campden tablets and potassium metabisulfite (K-meta) powder, protects the wine and extends the lifespan. Most wild microbial life is not sulfite resistant, and K-meta's antioxidant properties neutralize a lot of other problems, including O2.

 

[Rice_Guy]

From a micro point of view, beer is quite different. Beer starts with a mash that has sat at ambient letting everything that has an enzyme that can break starch grow. Beer can be pH 5, fruit wines aim for 3.2 to 3.5 and red grape 3.5 to 3.7. Essentially food poisoning organizisms don’t survive under 4, beer again is in a risk zone. Alcohol is a protectant, 5% is a minimum barrier, 10% ABV is a stronger micro barrier. CO2 helps but is more important in a beer system, CO2 makes it anaerobic to finally remove many families of micro out of beer.

One can make wine without metabisulphite, BUT we get significantly better shelf life by using it. I would not try to enjoy a country wine that is over six months if it had no added SO2. Red wine has tannin (polyphenols) which are antioxidants so one can make an organic red with a few years life. Practically speaking a number of crops are good tannin sources so one has a few choices. ,,, But it is easier and one can get away with sloppy processing with added SO2.

 

[BigDaveK]

You got some great advice so far and since you mention an interest in fruit wines I'll go in that direction.

Like you I try to stay away from chemicals if possible. I never use kmeta at the beginning. I will pour hot water (190F-ish) over my fruit and that temp will easily kill unwanted interlopers. Some vegetables need to be simmered to break them down. Others ingredients like garlic and ginger need to be simmered to cancel their anti-fungal properties which may interfere with fermentation. As mentioned, NEVER BOIL.

The Joy of Home Wine Making is a good book.

Good luck and have fun!