My first wine

[Furn]

I have harvested my first homegrown grapes (Green Muscat), so I thought I would give winemaking a go.
This is what I have done so far:
Picked and destalked 15kg of grapes.
Pressed the grapes, added 3 Campden tablets to the grapes in a sterilized bucket. Measured the Specific Gravity: 1023. Left for 24 hours.
Added sugar (2.8kg) and yeast (BV7 Mangrove Jack's) to must. Put it all in a fermenting bucket fitted with an air lock and placed on a home brew heating pad.
Left it to ferment for a week.
I then racked into demijohn's with airlocks and took another Specific Gravity reading. It is the same as before 1023.
I have no idea what I have done wrong! It doesn't smell bad, it is cloudy and it tastes like sour grapes.
I'm not sure if I should continue with the second fermentation or just throw it all away?

 

[BigDaveK]

I didn't see mention of nutrient, pectic enzyme, acid blend or daily stirring. Oxygen is needed at the beginning.
I'm a beginner, too, so I'll stop there. I'm sure the wine gurus will weigh in soon.

 

[Jovimaple]

What was the S.G. after you added the sugar?

Many of us ferment in an open bucket covered by a towel, which allows for easy stirring once or twice a day. As @BigDaveK wrote, yeast need oxygen at the beginning of the process to reproduce. Fermenting under airlock works but can take a lot longer since the yeast colony may not be as robust without oxygen.

If it were me, I would stir every day and take the S.G. again in a couple of days. It is going to be cloudy at this part of the process, with yeast and pieces of fruit. Clearing takes time.

As an example, this is a tomato wine I made last fall.


This is the same carboy a few weeks later:

 

[BigDaveK]

As an example, this is a tomato wine I made last fall.

Nice!!
I'll be starting my first batch of tomato before the weekend. I still have about 30#'s from the garden in the freezer.

 

[Jovimaple]

@BigDaveK Lots of lees with tomato! I ended up with just over 2 gallons of wine out of that 3 gallon carboy.

 

[Rice_Guy]

Welcome to wine making talk

* 1.023 is low for sugar content on a picked grape. With vinifera and northern hybrids we target picking when sugar is 1.090. One implication from low sugar is that pH is low. Yeast do not like living below pH 2.8, so they would be struggling. A second implication is that more sugar is needed. 2.8 kg sugar in how much juice? Yeast don’t like over 1.120 starting gravity.
* good news, most organisms don’t like living below 2.8. The risk of any food poisoning organism is very low, and with a metabisulphite treatment other than aerobic molds one shouldn’t find anything. ,,,, IF you have access to a pH meter can you test pH? Do you have a high school kid who could have the chem teacher test it? pH is like a fence that keeps many families out
* Is there any alcohol taste? ,,,, Restarting at this point I would treat the juice as a skeeter pee. (I haven’t done one, others will chime in) Skeeter is lemon juice which is very- very acid as 2.4. To get it to ferment a yeast starter is made which has enough cell density to do the fermentation.
* nutrients, God made grapes with a good nutrient balance so I wouldn’t make this a first concern.
* heating pad? Most wine yeast has a specification of 50F to 80F. Do you have a temperature reading? ,,, realistically a lot of yeast will take 40f BUT very few will take 85F.
* last of all wine is very forgiving, ,,, people discovered the process 5000 years ago occurring naturally in fruit. All we really do today is we put names on where the fences are which increase the odds of success to close to 100%.

 

[sour_grapes]

Welcome to WMT!

May I ask how you are measuring the SG? (Hydrometer or refractometer?)

How does the juice taste right now?

 

[Furn]

Thanks for all of the helpful advice. The tomato wine is looking great.
With my wine making attempts, I did stir it every day while in the fermenter and I only took the two readings with a Hydrometer. I never took any other readings, to be honest I thought to test anything else. The airlock was bubbling the entire week and the reason for the heat pad was because it gets cold in my house and I thought a steady temprature might help. The taste at the moment is of sour grapes and mild alcohol.
I'll keep it going and let you know how it's going.
Thanks everyone.

 

[sour_grapes]

The thing that confuses me is that I would expect that, with a SG of 1.023, the must would taste very sweet! Are you sure that the hydrometer is floating freely?

 

[BigDaveK]

@BigDaveK Lots of lees with tomato! I ended up with just over 2 gallons of wine out of that 3 gallon carboy.

Yeah, I see that!
My tomatoes are still in the freezer but today I weighed - 27#'s. I'm still burned out from last year's canning so - screw it - they're all going to wine!
I found your recipe and a couple others and will probably use yours with minor tweaks like tomatoes per gallon and yeast. I only have 71B and 1118 in the fridge. I'm still new at this - and very happy with the results so far - so adding more yeast varieties isn't a priority at this time.