Newbie Confusion: Open Fermentation of Fruit

[Beerfant]

I am getting ready to ferment strawberries into wine - More on that in a separate thread.

Many of the recipes I have come across require the crushed strawberries be left with pectic enzyme simply covered with a towel for 1-2 days, and then fermented the same way, i.e., just covered with a towel for 7 days before racking to a carboy. Following questions have been bothering me, especially considering the highs here are already in the 80s:

1. If I leave fruit (pulp) with pectic enzyme, (in my case, papaya peel) for a day or two, won't the fruit begin to rot and bacteria make a colony on it?

2. If the must is fermented for the first 7 days, open, just covered with a clean towel, won't it get oxidized due to excessive oxygen?

Cheers!

 

[Beerfant]

I forgot to add, Campden tablets are not available

 

[WVMJ]

If you dont have camden then get some, strawberry does oxidize easily once its finished. Your yeast need some oxygen to reproduce at the begining, and they make a lot of CO2 during the initial ferment, this protects the wine from oxidation. We typically use 10lb/gal of strawberries, crush them, add Pectinase for 12 hrs, then KM for 12, then the yeast. Make a slurry of your peels to get more enzymes out of the peels quicker. Once your gravity drops to like 1.020 or even lower you can rack into a carboy and put on an airlock, oxygen at this point is bad from now on. A little tiny bit of oak helps put a smidgen of tannins in a strawberry wine and helps it age better and tastes great. WVMJ

 

[gregbathurst]

Leaving pulp for a couple of days isn't such a concern, it may start to ferment but is unlikely to spoil.
leaving an open fermentation for 7 days is more of a worry, there is a good chance it will turn to vinegar or some other spoilage. I ferment my cider and wine in an open fermenter but for 4 days max, usually 3-4 days, then it goes under a good seal with an airlock. Some recipes don't consider different climates, in a warm climate fermentation will finish much quicker. racking off at 3 days won't hurt your wine.

 

[Beerfant]

If you dont have camden then get some, strawberry does oxidize easily once its finished. Your yeast need some oxygen to reproduce at the begining, and they make a lot of CO2 during the initial ferment, this protects the wine from oxidation. We typically use 10lb/gal of strawberries, crush them, add Pectinase for 12 hrs, then KM for 12, then the yeast. Make a slurry of your peels to get more enzymes out of the peels quicker. Once your gravity drops to like 1.020 or even lower you can rack into a carboy and put on an airlock, oxygen at this point is bad from now on. A little tiny bit of oak helps put a smidgen of tannins in a strawberry wine and helps it age better and tastes great. WVMJ

Thank you for your reply. I live in a country where I cannot get any wine making supplies except what occurs naturally. The laws do not allow me to order these products from abroad.

People did not always have all these specialized chemicals, so I'll also go the natural route. For sanitization, I'll boil some water and pour over crushed strawberries that have already been washed and frozen. I believe that should take care of the germs left even after washing. I plan blending the papaya peel and pouring that over strawberries once cool enough.

For tannin I intend adding half cup of strong black tea. I am also considering a stick of cinnamon that should give the wine an interesting flavor in addition to the tannin.

 

[bernardsmith]

The amount of time you want to leave the fruit in an open container has very little to do with time and everything to do with the production of CO2 (and so the level of active fermentation). Do you have any means to measure the specific gravity of your wine? Although it may be illegal to purchase wine making equipment and instruments you may be able to find an hydrometer (hydrometers are used to check the concentration of many kinds of liquids, not just alcohol) . The key point is that when the gravity is getting close to 1.000 (I would suggest about 1.010 to 1.005 then you want to rack (transfer) the wine into a carboy or vessel with a narrow neck that you can seal with an airlock (could be a balloon or condom) or and which you can fill so that there is no headroom to speak off (perhaps an inch of space between the surface of the wine and a drilled bung (as the yeast will still be producing some CO2 there needs to be some way for the gas to be allowed to escape and not build up as the pressure which the gas can produce may be enough to burst the glass...)

 

[buMbLeB]

1. If I leave fruit (pulp) with pectic enzyme, (in my case, papaya peel) for a day or two, won't the fruit begin to rot and bacteria make a colony on it?

2. If the must is fermented for the first 7 days, open, just covered with a clean towel, won't it get oxidized due to excessive oxygen?

Cheers!

I can answer the second question, as I've fermented a variety of peels and pulps in both carboys and wide-mouth jars - no. Assuming your fermentation kicks in on schedule (within a handful of hours) the yeast should make enough carbon dioxide to push out the oxygen. Since CO2 is heavier than air, it will make an invisible blanket over the must, just don't slosh it around or otherwise disturb it.

As for #1 I dunno, from my experience strawberries start to decompose before I get them home from the supermarket, so yes I'd imagine leaving them out for a day or two anywhere other than Antarctica is asking for spoilage - maybe that little bit is ok and gets overwhelmed by the yeast? No idea.

 

[gregbathurst]

I can answer the second question, as I've fermented a variety of peels and pulps in both carboys and wide-mouth jars - no. Assuming your fermentation kicks in on schedule (within a handful of hours) the yeast should make enough carbon dioxide to push out the oxygen. Since CO2 is heavier than air, it will make an invisible blanket over the must, just don't slosh it around or otherwise disturb it.

This is a common misconception. A blanket of co2 doesn't protect your wine, unlike liquids gases can mix in the same volume without increasing the total volume - this is one quote I found

"How can two or more gases in a closed container each occupy the entire volume of its container?

Answer: Ideal gases are considered to be point particles, the volume of each gas molecule is considered so small, it is not important. Ideal gases do not attract or repel other gases, therefore the intermolecular forces among the gase molecules is not important. Because gases consist mostly of empty space, the distance between gas molecules is large enough so that each gas molecule does not "see" another gas molecule. This is another reason why there are no interactions with other particles."

CO2 is protective while enough is produced to push out other gases faster than they can enter the container. Once fermentation slows down or stops co2 isn't protective any more.

 

[buMbLeB]

This is a common misconception. A blanket of co2 doesn't protect your wine, unlike liquids gases can mix in the same volume without increasing the total volume ...

Fascinating, I learned something new! On the other hand, I've done it several times with success, and since OP is contemplating only 7 days until racking I think my reply is *effectively* correct in the context of the question.

Thanks though!

 

[Beerfant]

The amount of time you want to leave the fruit in an open container has very little to do with time and everything to do with the production of CO2 (and so the level of active fermentation). Do you have any means to measure the specific gravity of your wine? Although it may be illegal to purchase wine making equipment and instruments you may be able to find an hydrometer (hydrometers are used to check the concentration of many kinds of liquids, not just alcohol) . The key point is that when the gravity is getting close to 1.000 (I would suggest about 1.010 to 1.005 then you want to rack (transfer) the wine into a carboy or vessel with a narrow neck that you can seal with an airlock (could be a balloon or condom) or and which you can fill so that there is no headroom to speak off (perhaps an inch of space between the surface of the wine and a drilled bung (as the yeast will still be producing some CO2 there needs to be some way for the gas to be allowed to escape and not build up as the pressure which the gas can produce may be enough to burst the glass...)

Thank you for your reply. I agree I can get a hydrometer. In fact, new online stores have recently sprung up that are ready to buy almost everything from the US and supply at home - shows I'm not the only one engaged in this hobby here! They are kind of expensive, and quote 3-4 weeks delivery. I didn't order anything as it would soon be too hot to ferment without adding fusels to your wine. I plan to accumulate all the essentials before next winter.

As for the process of fermentation, I am already familiar with it. My first attempt was in last summer, when I made Ed Wort's Apfelwein. It all went great except that the great tasting wine gave headaches because of fusel alcohols. Last month, I fermented red grape juice. It is already in the secondary, waiting to clear out. It seems to have come out pretty well.

This, however, is my first experiment with fresh fruit. I started the process today, by hand crushing 3 kg (6.6, let's say 6 lb after wastage) strawberries in a food grade plastic pail with a lid and adding peels from one whole papaya. I intend adding 3 lb sugar (1 lb brown, and 2 lb white cane sugar,) a handful of raisins, 1/2 cup strong black tea, a stick of cinnamon, one packet of dead (boiled) yeast, and one packet of live yeast. Let's see how it all goes. once the primary fermentation has taken place (in 4-7 days) I will siphon the wine into a clean 6 liter water bottle. I intend holding 1/2-1 lb sugar back that I will boil in water, cool, and add to the secondary, to eliminate headroom.

What really worries me is how the strawberry-papaya peel must will manage to not start rotting and molding by the time I add yeast.

 

[Beerfant]

Not sure if I should add the brown sugar later to the secondary, or the white one

 

[gregbathurst]

Fascinating, I learned something new! On the other hand, I've done it several times with success, and since OP is contemplating only 7 days until racking I think my reply is *effectively* correct in the context of the question.

Thanks though!

The answer to how long you can leave wine uncovered is "it depends".
If you ferment cool your wine will ferment slowly and you can leave it longer. If you don't have any way to keep it cool it can ferment out dry in a few days, depending what sort of wine you are making. After that if you leave it covered just with a towel it will spoil quite quickly. The obvious thing is to monitor the sg so you know when it has finished, as others have said, but don't wait till it gets to 0.000, you may be too late. If wine is fermented very slowly, it will need to be in a sealed container the whole time, because it won't produce enough co2 to be protected.

 

[Beerfant]

Leaving pulp for a couple of days isn't such a concern, it may start to ferment but is unlikely to spoil.
leaving an open fermentation for 7 days is more of a worry, there is a good chance it will turn to vinegar or some other spoilage. I ferment my cider and wine in an open fermenter but for 4 days max, usually 3-4 days, then it goes under a good seal with an airlock. Some recipes don't consider different climates, in a warm climate fermentation will finish much quicker. racking off at 3 days won't hurt your wine.

Just as I feared.... without the availability of Campden tablets, the crushed strawberry and papaya peel mixture began to give a slightly rotten fruit smell within 12-14 hours. I decided to put my bucket in the fridge till the evening, and with 24 hrs completed, I added 1 lb brown sugar and 2 lb white cane sugar to a couple of liters of boiling water, let it cool, and added to the bucket. I also added a handful of raisins chopped in a blender, 1 teaspoon of citric acid, half a cup of strong black tea (brewed) and a stick of highly aromatic cinnamon. When the must was cool enough, I pitched in a 11g packet of instant dry yeast... I forgot, I also boiled a packet of yeast with the sugar syrup.

I allowed the must to ferment in the bucket with lid on for 2 days, then filtered it through a sieve, into a 6-liter PET bottle and sealed it with an airlock. Yesterday, after 12 days of fermentation (that had completely stopped) and the wine had cleared halfway or a little more, I racked it once more into another bottle. I filled the empty space with syrup made from 1 lb of brown sugar. and put he airlock again.

While racking the second time, I tested the wine for the first time with a sip. I can tell you I have a very crisp and pleasant strawberry flavored drink with enough ABV to give you the burning sensation as it goes down your throat. There is however, one big problem....

The wine, while very nice overall, gives a hint of rotten fruit
My question is: Can I expect to lose that off taste/smell with age? Is there anything I can do now to get rid of that smell?

Another problem I am facing is since the second racking, and despite addition of 1 lb brown sugar, there is absolutely no fermentation going on. I am afraid I added too much sugar, so now I am left with a very sweet wine. Should I try pitching in some more yeast? If I somehow get hold of Montrachet yeast, would that help restart the fermentation?

Thanks!