Wine not?

We processed the grapes by hand and got half a bowl of white and a big pot full of red. They were delicious by the way!

We crushed the grapes with the Mouli and got a glass full of green juice from the Solaris, which we drank. We got a jar full of must from the Rondo which Alex topped off with a little water and some yeast dissolved in 3/4 cup of boiled lukewarm water. The must is thick and we couldn't put it in a 5L demijohn, so we used my 2L apple cider vinegar jar and it promptly overflowed overnight. We then spilt it into two jars with plastic pull-on lids which let the air escape. 

The only good news is that the Brix measurement by reflectometer is precisely 20. 

How do farmers do it year after year?

Correcting the sugar content

Looks like we messed up. 

Our red must has tested at just over 1.008 on the hydrometer and 5 on the Brix scale. That won't get us to the right alcohol content - too low. We should have added sugar to the must at the first stage but we didn't.

When making wine, the Start Gravity should be 1.070 (normal finished ABV will be 10.5%) to 1.090 (normal finished ABV will be 13%). Finish Gravity should be 0.990 (for dry wines) to 1.005 (for sweet wines).

Alex made a simple sugar syrup dissolving sugar in boiled water. We have to wait for it to cool to room temperature. 

Now we have to figure out how much syrup to add. Because I had to dilute the sugar solution by half to get the hydrometer to read the SG, the specific gravity of the syrup is 1.110 x 2  or 1.220. 

So to increase the SG to where the potential alcohol would be sufficient, we'd have to add 40 oz sugar per gallon or 2.5 lbs per gallon. That would be 1 l of water or 1.5 l of syrup. (Alex did the maths.)

Just as a note to self:  3 kg water plus 3 kg sugar = 1 demijohn.

So we expanded our two demijohns to three with the sugar syrup and must (stirred to keep the yeast equal) divided equally among the three. I tested the SG of the resulting must and it read SG 1.070. That should get us to over 9% ABV. 

Curiously, I just measured the SG of the Solaris must, and it, too, reads 1.008. Not surprising as it started out at the exact same SG as the Rondo must. So we'll have to repeat the procedure for the white. 

So we have 1.5 l of Solaris must, measured by weight. So if we need 40 oz sugar per 3.78 l above, we need:

40/3.78 = x/1.5 = 15.9 or 16 oz of sugar. We added 16 oz of sugar dissolved in 16 oz of water to the 1.5 l of must and essentially doubled the volume. The SG read 1.082, a little higher than the red but perfectly fine. 

Let's hope we have restarted the fermentation. At least we now have 1/3 more wine to bottle. 

Here are 10 more things that can go wrong in fermentation. 

https://www.brewersfriend.com/abv-calculator/ 

Making wine

Yesterday, we decanted and strained the Solaris must through cheesecloth in a sieve and squeezed all the remaining juice out of the grapes through the cloth. We measured specific gravity of 1.0075 so we don't have a long way to go. The liquid is quite cloudy so it will take some time to clarify in the demijohn. The tiny drops I tasted were actually quite good but strongly flavoured.

We had a lot more red must from the Rondo grapes so Alex devised a method of forming a ball in the cheesecloth and squeezing it in his hands. We pondered whether we should make grappa but thought better of it. 

Again the specific gravity read 1.0075 so we surmised we harvested a bit early. For next year, I have purchased a refractometer so we'll be a bit more scientific. Last year, our Rondo came in at 1.02 so we had a long way to go to get to .99. This year, we won't have as much alcohol content. The juice tasted much sweeter last year. This year's juice is a bit harsh tasting but the smell is lovely. 

So we have one demijohn of white and two of red. That's getting better already. Now we wait. The trouble is, we have forgotten from year to year what we need to do. I suppose I should take a course. 

Mashing the grapes

After destemming, which took many hours, we tried various ways to mash the grapes. I started with the stainless steel Moulin on the white grapes. It was hard work. 

We tried the potato masher but that didn't work very well at all. Alex tried the potato ricer but that was too hard and didn't really work. Then Alex found the insert with bigger holes for the Moulin and that worked pretty well for mashing the 16L of red grapes. It didn't take him that long but I would not have been strong enough to get through that volume. Even with the small quantity, my arms and back are quite sore today. It was quite awkward. 

We measured the specific gravity which read exactly 1.060 on the hygrometer. With that reading, we should be adding some sugar. But we didn't last year and our fermentation went well. 

We decided not to use Campden (sodium metabisulphite) tablets so we were able to proceed to adding yeast and beginning the fermentation. Alex has a strong dislike of sulphites, which Campden tablets release. You do that to kill bacteria that can ruin your wine. But then you have to wait 24 hours to add yeast or the yeast will die. 

So this year, I dissolved one tablespoon of caster sugar in warm water, then let it cool. I added three teaspoons of yeast and covered the jar. That was for the red wine. I did the same with just 1 teaspoon of yeast for the white wine. After about half an hour, with the yeast almost bubbling out of the cup, Alex mixed the yeast into the must. Now we wait 6 days for the primary fermentation. Each day, we stir the must to ensure that the grapes, which float to the top, stay immersed in the must. 

The crusher/destemmer we are looking at is the SS model made in Italy by Polsinelli. We'll order it in the Spring so we allow enough time for delivery. 

In Sonoma, vintners are testing a new method of destemming and juicing on-site in the vineyard. We aint there yet. 

I just ordered a dessert grape called Vanessa for the polytunnel. It's a most unusual colour and almost seedless. 

The second stage

We racked the wine into the demijohn and corked it with the oyster farm cork with fermentation airlock. It smelled very good and Alex said he tasted it yesterday and it was good. But the specific gravity was 1.02 so we have a little ways to go to get to 0.99. It might be just a little cool in the pantry area. It will remain there for about two weeks before stabilizing. 

There is not much more to this stage so we'll just wait and hope it continues to ferment a little more. Meanwhile, the remaining grapes, those that were way behind ripening, are not ready to pick and eat. 

Making the wine

Lovely morning but heavy rain due all afternoon

I've been reading up about how to make wine at home. Unfortunately, none of the descriptions covers our situation so we have had to punt. We mashed the grapes by hand and with a sterilized wooden meat tenderizer. That worked reasonably well. For ten days, the grapes have fermented. Alex stirred daily and the bubbling going through the fermentation airlock was at times scary and loud but very satisfying. 

I bought yeast and Campden tablets. But how to extract the liquid from the vat after the first fermentation? Alex decided my muslin bag for making apple jelly was just the thing. Well in no book have I seen this, but it's worth a try. We found a nice demijohn at Ross House and cleaned it up. It looked like it hadn't been used in 30 years. Full of dead bugs and spiders. But it cleaned up beautifully and I sterilized it with the stuff that came with the winemaking kit. 

Alex found some predrilled stoppers from his old oyster growing days and they happened to fit the demijohn and the airlocks perfectly. Stage 2 would be completed without additional expenditure. And as the final steps of stabilising the wine won't be necessary -- we're going to have maybe 2 bottles if we're lucky -- we should be bottling on about a week. I'll report the specific gravity in the next post after we've measured it. 

BTW, YouTube has loads of useful how-to videos:  https://youtu.be/n7tauROWh0Y  

So what's next in making our wine

Hydrometer suspended in grape juice

The wine must has to ferment for about 2 weeks in the first stage. When fermentation stops, you have to test the specific gravity. When making wine, the Start Gravity should be 1.070 (normal finished ABV will be 10.5%) to 1.090 (normal finished ABV will be 13%). Finish Gravity should be 0.990 (for dry wines) to 1.005 (for sweet wines). 

I've seen many recommend that wine should be fermented down to dryness. If you like a sweeter wine, you can then add sugar or grape juice at the end to reach your preferred sweetness. It is a dangerous business stopping the fermentation early. 

So the hydrometer is probably the most essential piece of equipment to make wine with success. I've ordered a spare as I can imagine that it's pretty easy to break. I've also read about how to read the hydrometer properly. You have to make sure your hydrometer is floating freely and not stuck against the cylinder. You read at the bottom of the meniscus not the top (I remember that from chem class). It measures the Specific Gravity (SG) of the liquid being fermented. This will then in turn give you a guide to the Alcohol by Volume (ABV) you will be able to produce. The hydrometer is used throughout the fermentation to ensure sugar is being converted into alcohol. As more sugar is converted to alcohol, the SG will fall.

The Alcohol by Volume (ABV) is calculated by subtracting the start gravity from the finish gravity and dividing this figure by 7.362. For example, the starting point for our wine is 1.100 and if this ferments down to 0.990, the drop will be 110 points. This divided by 7.362 is 14.94% ABV. That should kick a punch. 

You have to make certain the fermentation is complete and stopped at the right time. Sometimes fermentation slows down or stops too early. A stuck fermentation is one that falls short of reaching the expected final gravity, and as with many things brewing, the term is relative. A wine that stops at 1.000 probably suffers more from poor instrument calibration than it does from stuck yeast. A 1.100 wine that stops at 1.045, though, still has a way to go and needs some help.

There are tricks that one can use to restart the fermentation process. One is temperature. If the hydrometer is placed in water at 20°C, it will read 1.000.  Most people only use the hydrometer as a guide but if you want to be really accurate then this should be done with a liquid temperature of 20°C. If the liquid is 5°C higher then add 0.001 and similarly if its 5°C lower then delete 0.001.

Warming up the must is probably the most reliable way to restart a stalled fermentation. Some yeast strains are more temperature-sensitive than others and may require some warmth to complete the job. Some strain are famous for refusing to budge until they are warmed as high as 95°F (35°C). Some British yeasts are stubbornly flocculent; it’s worth giving the must a good swirl a couple of times a day just to keep the yeast cells in suspension until they’re done.