Specific gravitas?

Posted: 3 years ago Quote #19
Hi wine making gurus,

I am making red wine for the first time using 3 buckets of red grapes grown on my allotment and using your website as a guide. I would like the wine to be dry and if possible, lowish in alcohol, so I would like to keep the sugar content down. But I am a bit confused by the process and my hydrometer readings and need to ask your advice.

This is what I have done:

With clean feet, I mashed approx 15kg red grapes divided between 2 plastic boxes, the grapes contained within muslin/net bags.
Each has produced about 1 gallon liquid. I removed the stalks, left the bag of grape skins in, and added 300g sugar to each box plus a scant teaspoon of bordeaux yeast (approx 5 g). I put the lids on and placed the boxes in my warm hallway.

The specific gravity reading was somewhere in the blue section of my Stevenson Reeves hydrometer -  which is labelled 'start wine', so i took this to mean it was about right to start. On the three scales the blue section runs between : 45-90 ,  7.2 - 14.5  and 120 - 245.

24 hours later, one box had bubbles the other not. I added 5g more yeast to the dormant one and pushed down the must in each. Bubbles started within a few hours.

48 hours later I have taken a specific gravity reading  of 50/ 8/ 135 (ie near the top of the blue section) and a thermometer reading of 26 degrees.

What I'm not sure of is if I am meant to be adding more sugar, which I am reluctant to do in case I end up with horribly sweet wine. In 3 days time, should the hydrometer reading be in the yellow section - ie around 1.000/10?

I am also trying to get away without campden tablets as sulphur compounds give me allergic reactions, (sneezing/ loss of sense smell)  - am I being foolish?

Huge thanks in advance for your help,
Hannah
Posted: 3 years ago Quote #21
First of all I would say definitely don’t add any more sugar, especially if you are as you say, aiming for an absolutely dry, low alcohol wine. Almost certainly you will have added sufficient already.  I myself share your distaste for horribly sweet wine produced by overloading the yeast with sugar and would always caution against it. It’s a pity you don’t have an exact hydrometer reading of the juice before you added the yeast at the beginning. A reading of 50 after 48 hours won’t tell you very much because a lot of sugar will already have been converted to alcohol and carbon di oxide. One problem with the Stevenson Reeves hydrometer to bear in mind is that although fine for measuring specific gravity, the scale it has for potential alcohol is well overstated. Looking at the winemaking tables supplied by Plumpton College I get 1.045 (45) giving a potential alcohol of 5.3% by volume and 1.090, 12.4%. I shall be putting more of this information on the website in the near future and updating Richard’s advice.

I would say that what you are doing is so far so good. You will need to push the grape skins down into the wine twice a day while they remain in the wine. I would be inclined drain the wine from the skins as soon as it has developed the colour you want, 4 or 5 days maybe. The longer you leave it after that the more bitter tannins you will be extracting from the skins. This is all very well if you are making wine for long keeping but that also means quite a long time before it’s drinkable.

I would think it’s likely to take a bit longer than another three days to fully ferment out as the activity slows down as the gravity drops. So the wine you have drained or squeezed out of the skins should be put in demijohns or other suitable containers and put under airlock. When it is finished the hydrometer should in fact read below 1.000, the gravity of water at 20 degrees, if all the sugar has been used up, because alcohol is less dense than water.

Are you ok not to use campden tablets? Well adding Metabisulphite to produce Sulphur dioxide in the must is like an insurance policy, which is why it is generally done commercially.  So you are making wine without that insurance, which is your choice. A choice which is becoming quite fashionable I think. Earlier this year I tasted some very nice wines that had been made by this fashionable, very low or no sulphur method. However on the basis of a complete disaster I had some years back I do myself always use the insurance of SO2 these days. I would say though, as you have added winemaking yeast quickly, the chances are you will be ok, fingers crossed!

I hope this has been useful, feel free to email or phone me if you have any more questions.
Posted: 3 years ago Quote #22
I can be contacted through calling our store or emailing us through our contacts page. BTW sorry for the delay.
Posted: 3 years ago Quote #23
Dear George, thank you so much for your detailed and clear response - exactly the advice I need. Fingers crossed on the non insurance front, hopefully I've minimised the risk by sterilising everything in sight!
I'm way on the other side of London but hope to visit your shop soon.
Big thanks, Hannah