DIY prosecco

[tonyhibbett]

Carbonated the last bottle of rhubarb. Mother nature kindly brought it down to -2c overnight, so no need for the freezer. Champagne has various grades of sweetness. 'Natur' is less than 1g of sugar per litre - no sugar added. 'Extra brut' is up to 6 and rare. 'Brut' is 6 to 12. Adding 1 Sweetex to a bottle is the equivalent of 5g per litre, so the glycerine in fact only takes it up to brut, so 'medium dry', or even 'extra dry' is incorrect. This time I measured the acidity after carbonation and it had gone up from 5 ppt to 7.5, an increase of 50%!
The next step is to carbonate the chardonnay intended for the prosecco experiment. This is not the base wine (glera) used for prosecco but champagne is 50% chardonnay.
Incidentally, the beer did not freeze at -2c.

 

[tonyhibbett]

The wine is pretty ordinary stuff with an acidity of 6.5 ppt, which after carbonation would be too high, so I added 1 g of potassium bicarbonate to the bottle, along with the Sweetex and glycerine. I went into the freezer at 5 c and came out 2 hours later at -5 with ice just beginning to form. After carbonation, the acidity was 8 ppt but it tasted fine, although lacking that special 'bready' flavour of autolysed yeast you get from aged bottle fermented bubbly. Therefore I am calling it 'Shampagne'!
I completed the assembly of the counter pressure filler. There was a slight leak at the t piece, which stopped once the system was pressurised. I had 10 empty 500 ml swing top bottles and set up a production line in the kitchen. After a couple of mishaps I got the hang of it, but it requires concentration, with no distractions. After filling 10 bottles, I switched to 640 ml standard beer bottles, with the crown capper at hand. After 6 bottles the keg was empty. After cleaning, it will be ready for the wine.

 

[tonyhibbett]

Non vintage champagne is a blend including previous vintages to provide some consistency. I have 15 bottles of the 2016 vintage, which less acidic so I'll mix this 50/50. It's best to use chardonnay within 3 years, so no point in hanging on to it. Both are bone dry, so I'll add the usual 1 Sweetex plus 3 ml of glycerine per litre, making it brut. I'll do a test sample with the Sodastream. I'll need more sparkling wine bottles.
There was no liquid left in the keg - just a small pool of largely undisturbed yeast. The surplus gas effectively cleaned the liquid feed tube to the counter pressure filler, which is most convenient!

 

[tonyhibbett]

It's a good blend, with the right acid balance. However, there is no aroma and not much flavour. Having said that, this applies to most off the champagne and all of the prosecco I have tasted. In order to provide a 'floral note' I have ordered some dried elderflowers which I will soak in some of the wine to make an infusion to be added to the bulk.

 

[tonyhibbett]

I opened a bottle of the beer and found it to be sparkling, unlike when it was draught. Bottling was done under a counter pressure of just 10 psi, which bodes well for the wine.
I rarely consume a whole bottle of sparkling wine in one session, so I have invested in a 'bar amigo' champagne keeper. Unlike most of these, this one enables you to push button pump in air to re-pressurise the bottle. I opened a bottle of the 2015 fragolino marked 'low fizz', which turned out to be 'no fizz', but nonetheless pleasant. After a glass, I applied the bar amigo, pumped it up and replaced the bottle in the fridge. Next day, I removed the stopper and a cloud of vapour escaped. The wine was now slightly sparkling! Air is mostly (78%) nitrogen and this is the preferred gas for use with stouts like Guinness rather than co2. Although the wine had no sparkle, it was probably saturated with co2 and pumping in air was enough to release the latent co2.
Meanwhile I have made an elderflower infusion, using 50 g of dried elderflowers with some boiling water in a sweet jar and topped up with the base chardonnay when cool and left for 24 hours. I then sieved this and then filtered out the fine solids using a paper coffee filter in a funnel. This was quite slow but effective.
To gauge the effect I mixed 5 ml with 125 ml of the base wine and could detect no difference in flavour. So I added a bottle of the base wine to the sieved elderflowers and left it for 24 hours for further extraction. This gave me 2 bottles of 'concentrate'. Mixed at 10% with the base wine seemed to improve the flavour, without any aroma or elderflower taste. So i will make up another 2 bottles with 50 g of dried elderflowers and try again at 20%. This would be about half the amount for a traditional elderflower wine.

 

[tonyhibbett]

The dose of elderflower (100g dried to 4 gallons) is about right for use as a flavouring component rather than elderflower wine. I mixed the 2 vintages, the extract, 24 Sweetex and 75 ml of glycerine into the keg, fitted the carbonating lid and set the pressure to 40 psi. This is supposed to instantly carbonate the wine but it didn't. The result was the same as the beer - lots of foam and no sparkle. I rigged up the counter pressure system and attempted to fill a bottle. There were 2 leaks which I managed to fix but it seems that 40 psi is too high for me to hold the bung in place. However the temperature of the wine was 14 c. I did manage to almost fill a bottle and produce some sparkle. The flavour was good and there is a faint aroma of elderflower. This may be as good as it gets, but I will try again when the temperature has dropped to as close to 0 c as the weather permits.

 

[tonyhibbett]

In order to hold the filler steady and apply more pressure to the bung, I have ordered a 500 mm tall pillar drill stand. This also means I won't have to touch the metal parts when very cold. I have also extended the outlet tube so that it reaches closer to the bottom of the champagne bottles. Weather is still fairly mild at 10 c, so I'll leave the wine to (hopefully) carbonate more.

 

[tonyhibbett]

Drill stand arrived, but there is no obvious way to secure the filler where the drill chuck would go. I made a 10 mm thick wooden collar by using a 38 mm diameter hole saw and cutting out the centre with an 18 mm wood bit to make a ring, then cut in half. The 2 pieces make a tight fit around the nut above the bung. However there is not enough clearance to insert the filler tube into the bottle. So I loosened the nut that secures the stand's pillar so I can swing the whole unit away from the stand over the edge of the work surface. Once the filler tube is inserted in the bottle, it can be swung back so the bottle sits on the stand. I can then lower the lever to insert the bung into the neck of the bottle with just enough pressure to hold it in place at 30 psi, then wedge the lever to keep it there hands free. This worked well when I opened the valve to pressurise the bottle with the bleed valve closed, but there was a leak at the t-piece. Once that was fixed, I tried again. Once the hissing in the bottle stopped, I switched the valve to enable the liquid to flow. As expected the liquid did not enter the bottle until I opened the gas bleed valve a little. The bottle slowly filled and when near the top, I switched off the flow of liquid and released the lever to release the bung, then swung the unit over to remove the bottle. Before capping the bottle I poured a glass. No fizz! I put this down to the temperature, which was 10 c. The next morning the temperature was down to 3c so I tried again, this time successfully! I managed to fill 6 bottles and that was enough because the process requires great concentration. Also the collar had edged its way up due to the great pressure and needed to be pushed back down.
The high pressure gauge is now at zero so the gas bottle will need to be refilled soon. This is the problem with working at 30 psi to fill wine bottles - you get through a lot of co2.

 

[tonyhibbett]

I am very pleased with the wine. There is enough sparkle to to give the 'mousse' effect in the mouth and the bubbles are small and of long duration, neither of which is said to apply to carbonated wine. I see no need to increase the psi above 30.
The weather obliged me with 1c and sunshine. I still had to secure the collar, which was easily done. I used 4 x 75 mm repair plates and 4 x m5 50 mm machine screws and nuts to make 2 clamps, one for each side. This worked perfectly.
I used a 7 bottle metal wine rack on its side to store 6 sparkling wine bottles near the filler to chill. I found a suitable hose to connect the bleed outlet to a wine bottle which sits securely in the 7th space of the wine rack. This salvaged a glass of wine and saved a mess.
The bottles were of different heights. This proved very frustrating, requiring different size wedges to hold the lever in place plus adjustments to the crown capper, and one of the bottles wouldn't take a crown cap, so I had to use a plastic stopper and wire cage.
I placed a torch behind the bottle before filling to make it easier to keep an eye on foaming, but some bottles were still too dark to observe clearly.
To make for a bit more efficiency, I place the capper next to the filler and attached a bag full of caps.
Just another 8 bottles to fill, plus the labelling and the project will be successfully completed.

 

[tonyhibbett]

The temperature this morning was 5c, like a fridge, so I decided to finish the job. In the end I got 20 bottles. The gas ran out in timely fashion, expelling half a bottle of sedimented wine. The sediment was unexpected, as the wine was perfectly clear when put in, but the elderflower infusion may have contributed to it, and tartrate stabilisation too, due to cold storage.
To allow for different bottle heights, I made an adjustable wedge to hold the bung in place, using a bored rubber bung and an m8 50 mm machine screw, with the nut recessed into the rubber to prevent the screw from slipping down. Next time I will sort the bottles according to height.
I expected the gas to last longer, although there was some waste due to leaks and inefficiency during the learning process. The cost of gas per bottle was about the same as the Sodastream, but then I got twice the amount of carbonation.
Now I can sit back and enjoy the fruits of my labour. I don't think I will bother trying the tank fermentation method, as force carbonation gave good results. I found some instructions on the use of the carbonation lid and air stone. You start with 2.5 psi, wait an hour then increase to 5, and so on. Alternatively, you can temporarily replace the grey/white gas disconnect with a black liquid out disconnect and force the gas in through the liquid out valve, down the dip tube and directly into the liquid in bursts, just like a Sodastream. Both methods work best at -2c. A chest freezer would be ideal, but I have already spent way too much!

 

[tonyhibbett]

On replacing my co2 tank I discovered I could get double the amount of gas for just 25% extra plus an extra 50% deposit. Unfortunately he was out of stock!
I now have 60 bottles of sparkling wine, but all of the elderflower has passed its best after 3 years. Had I used boiled water to make the wine, all of the dissolved oxygen would have been removed, thus preventing oxidation.

 

[brewgoat]

Somewhat pedantic but boiling does not remove all the dissolved oxygen. Using Henry's Law :-
The equilibrium concentration of oxygen in water at 100°C in contact with air is 6.17 ppm (calculated using the Henry’s law constant for O2 in water at lOO C and assuming a P O2 equal to 0.21 atm).
However from https://www.researchgate.net/public..._Water_A_Comparison_of_Four_Common_Techniques
the outcome from their test was a residual amount of closer to 1 ppm so pretty low but still there.
The wine must would have further absorbed oxygen as it cooled and before a blanket of CO2 could form during fermentation. Therefore there is always a certain amount of oxygen lurking, slowly oxidizing away at your prize creation.

 

[tonyhibbett]

Thanks for that. I guess it's simply a matter of accepting that elderflower wine is best consumed before 2 years in bottle. It does taste bad, but has little of that flavour and freshness, and more like sherry. However, if I doubled the amount of grape juice to 2 litres per gallon it may be better preserved, as would adding sulphite at final bottling. Apparently the sulphur doesn't actually reduce the oxygen content, it's the other way round.