Kiwi winemaking in action

[Rice_Guy]

What would your initial brix of the fruit be when it's ripe and without adding extra sugar

2019; pH 3.36; TA 2.07%; 1.070 gravity (store quality)
2020: pH 3.21; (store quality)
>>> age room temp 1week>> pH 4.13; TA 1.47%; 1.054 gravity.

* basically the TA is high which means that a finished wine with 100% juice needs to be back sweetened
* your pH will be too low on green/ hard to press in fruit. The pH will rise to goal of 3.5 (+/-) and when the fruit is soft easy to bruise it should get some acid correction. For the purpose of pH treat water as transparent and not influencing the pH. With crop on your land you can do the best of both which would be to let some get very ripe (very high aromatics) and then mix back in enough firm/ ready to send to market fruit to drop the pH.
A second way to do this is to mix in a high acid fruit as lemon or rhubarb or tamarind.
* added clean water is transparent to pH (minor change) but has no TA. By the numbers one part of kiwi juice with two parts of water would get the TA in target without altering pH.

 

[winemaker81]

What would your initial brix of the fruit be when it's ripe and without adding extra sugar

I've noticed that grape growers tend to think in terms of brix, as do folks they taught. I'm not a grape or fruit grower, and I think in terms of SG, and have to look at a table when I'm translating.

As such, I tend to get what I get, then I may have to adjust. The west coast USA grapes I currently purchase tend to have a higher initial brix (sometimes too high), whereas when I lived in Upstate NY and purchased Finger Lakes grapes, the brix was often low. Fruit (country) wines? Never made one that didn't need sugar.

For a big red, I want an SG between 1.095 and 1.105, with 1.100 as my sweet spot. According to my table, that's 22.5 to 24.7 brix.

For lighter reds, my target is 1.085 to 1.095 (20.3 to 22.5 brix), with 1.090 as the sweet spot. I consider the same range for whites, although Chardonnay would be at the higher end while others might be at the lower end.

Fruit wines are in the same range, although for a heavy fruit such as Elderberry I might go as high as 1.100, while Apple would be in the 1.085 to 1.090 range. In the distant past I made wines with OG lower than 1.080, but wouldn't do it again, as the ABV is too low. Anything below 10% ABV reduces the shelf life, and lighter wines don't have a lot of shelf life as compared to heavy reds.

Please note the above ranges are approximate -- they are my personal guidelines, not hard-n-fast rules. I may have listed slightly different answers in previous threads, and in a given situation I may go outside the "guidelines".

 

[rajeevniro]

I've noticed that grape growers tend to think in terms of brix, as do folks they taught. I'm not a grape or fruit grower, and I think in terms of SG, and have to look at a table when I'm translating.

As such, I tend to get what I get, then I may have to adjust. The west coast USA grapes I currently purchase tend to have a higher initial brix (sometimes too high), whereas when I lived in Upstate NY and purchased Finger Lakes grapes, the brix was often low. Fruit (country) wines? Never made one that didn't need sugar.

For a big red, I want an SG between 1.095 and 1.105, with 1.100 as my sweet spot. According to my table, that's 22.5 to 24.7 brix.

For lighter reds, my target is 1.085 to 1.095 (20.3 to 22.5 brix), with 1.090 as the sweet spot. I consider the same range for whites, although Chardonnay would be at the higher end while others might be at the lower end.

Fruit wines are in the same range, although for a heavy fruit such as Elderberry I might go as high as 1.100, while Apple would be in the 1.085 to 1.090 range. In the distant past I made wines with OG lower than 1.080, but wouldn't do it again, as the ABV is too low. Anything below 10% ABV reduces the shelf life, and lighter wines don't have a lot of shelf life as compared to heavy reds.

Please note the above ranges are approximate -- they are my personal guidelines, not hard-n-fast rules. I may have listed slightly different answers in previous threads, and in a given situation I may go outside the "guidelines".

Great info on that.. just put my kiwi wines to the secondary fermentation and I've followed the steps of yeast starter.. since kiwis takes longer time to get ripe on the vine itself we tend to harvest it at an optimum time and let it sit with grains for a period of one week to 15 days.. every two days i check the kiwis and i choose whichever is ripe and make wines out of them.. so far I've put three 30 ltr carboys of kiwi where primary fermentation of one carboy is complete and is on secondary fermentation.. i could not get my air lock bubbling and i now think that adding campden and yeast together might be the problem. i racked the wines from one of the barrels and Im just fermenting the juice.. the flavours are intense and sugar is 18 brix.. the room temp is 72 degree Fahrenheit and I've prepared a yeast starter for this one..

( Note: my kiwi juice were in contact with the outer atmosphere for 4 hours

 

[rajeevniro]

I understand

2019; pH 3.36; TA 2.07%; 1.070 gravity (store quality)
2020: pH 3.21; (store quality)
>>> age room temp 1week>> pH 4.13; TA 1.47%; 1.054 gravity.

* basically the TA is high which means that a finished wine with 100% juice needs to be back sweetened
* your pH will be too low on green/ hard to press in fruit. The pH will rise to goal of 3.5 (+/-) and when the fruit is soft easy to bruise it should get some acid correction. For the purpose of pH treat water as transparent and not influencing the pH. With crop on your land you can do the best of both which would be to let some get very ripe (very high aromatics) and then mix back in enough firm/ ready to send to market fruit to drop the pH.
A second way to do this is to mix in a high acid fruit as lemon or rhubarb or tamarind.
* added clean water is transparent to pH (minor change) but has no TA. By the numbers one part of kiwi juice with two parts of water would get the TA in target without altering pH

 

[rajeevniro]

I understand the importance of brix.. but I've tried searching on how to measure the specific gravity.. and im still confused about specific gravity.. i hope I've figured out the rest of the part of winemaking

 

[Rice_Guy]

Brix is frequently done with an optical measurement in the vineyard. This is fast and fine as long as alcohol hasn’t formed. It needs to be corrected for percent alcohol in wine and the test tool was expensive.
Specific gravity is fast, uses a less expensive test tool, takes a bigger sample as 100ml cylinder, also could be corrected for alcohol BUT we usually just say target is 0.990 instead of 1.000(distilled)
Old technology was to see if an object as an egg would float or sink in the sugar solution, Next generation is to float a position switch in the wine/ beer and have Wi-Fi tell the phone what angle it is at which is converted into a density reading

 

[winemaker81]

I understand the importance of brix.. but I've tried searching on how to measure the specific gravity.. and im still confused about specific gravity.. i hope I've figured out the rest of the part of winemaking

Search on "hydrometer". It measures the density of a liquid with respect to distilled water. Water is SG 1.000, and everything is based from that.

After responding to you, I wrote a post for my site on the topic.. It provides a bit more detail and includes a Brix-to-SG conversion table.

https://wine.bkfazekas.com/determining-initial-brix-specific-gravity/

 

[rajeevniro]

I agree with Bob & Dave. Also, activity in an airlock does not necessarily tell you anything. Use your hydrometer -- if the SG reading doesn't drop, there is no activity.

Here are instructions for how I make a yeast starter.

Thank you so much for the info.. i did as instructed to make a yeast starter.. because i had used campden at my primary fermentation i prepared a yeast starter and put in I'm my wines after racking.. (the brix was the same for a week) .. the clear juice is intensely flavoured..
I put it to the juice 14 hours ago and this is what it's looking likego

Search on "hydrometer". It measures the density of a liquid with respect to distilled water. Water is SG 1.000, and everything is based from that.

After responding to you, I wrote a post for my site on the topic.. It provides a bit more detail and includes a Brix-to-SG conversion table.

https://wine.bkfazekas.com/determining-initial-brix-specific-gravity/

T the info.. i seem to be more clear about sg now . Have noted down the calculation on my wine journal

 

[rajeevniro]

Thank you so much for the info.. i did as instructed to make a yeast starter.. because i had used campden at my primary fermentation i prepared a yeast starter and put in I'm my wines after racking.. (the brix was the same for a week) .. the clear juice is intensely flavoured..
I put it to the juice 14 hours ago and this is what it's looking likego

T the info.. i seem to be more clear about sg now . Have noted down the calculation on my wine journal

I hope my primary fermentation is sorted.. planning to rack the wine a week later and start the secondary fermentation.. I've just added acid blend 2 tsp.. added campden tablets 24 hours prior and after 24 hours added yeast and acid blend.. i let it sit on a room temp for another 24 hours(room temp reading) 60 to 70%
And I've now covered it with airlock for the oxygen to pass..
Also during secondary fermentation.. should yeast be added again?

 

[rajeevniro]

Brix is frequently done with an optical measurement in the vineyard. This is fast and fine as long as alcohol hasn’t formed. It needs to be corrected for percent alcohol in wine and the test tool was expensive.
Specific gravity is fast, uses a less expensive test tool, takes a bigger sample as 100ml cylinder, also could be corrected for alcohol BUT we usually just say target is 0.990 instead of 1.000(distilled)
Old technology was to see if an object as an egg would float or sink in the sugar solution, Next generation is to float a position switch in the wine/ beer and have Wi-Fi tell the phone what angle it is at which is converted into a density reading

Seems to be so true.. looking forward to making 600 ltrs of amazing organic kiwi country wines..

my primary fermentation is sorted.. planning to rack the wine a week later and start the secondary fermentation.. I've just added acid blend 2 tsp.. added campden tablets 24 hours prior and after 24 hours added yeast and acid blend.. i let it sit on a room temp for another 24 hours(room temp reading) 60 to 70%
And I've now covered it with airlock for the oxygen to pass..
Also during secondary fermentation.. should yeast be added again?

 

[rajeevniro]

Search on "hydrometer". It measures the density of a liquid with respect to distilled water. Water is SG 1.000, and everything is based from that.

After responding to you, I wrote a post for my site on the topic.. It provides a bit more detail and includes a Brix-to-SG conversion table.

https://wine.bkfazekas.com/determining-initial-brix-specific-gravity/

my primary fermentation is sorted.. planning to rack the wine a week later and start the secondary fermentation.. I've just added acid blend 2 tsp.. added campden tablets 24 hours prior and after 24 hours added yeast and acid blend.. i let it sit on a room temp for another 24 hours(room temp reading) 60 to 70%
And I've now covered it with airlock for the oxygen to pass..
Also during secondary fermentation.. should yeast be added again?

 

[BigDaveK]

Also during secondary fermentation.. should yeast be added again?

No.
Many sources call it "secondary fermentation" but it's actually the same fermentation, just in a "secondary" vessel. During the first part of fermentation the yeast mostly reproduce and make CO2. Later they make ethanol and CO2.

 

[rajeevniro]

2019; pH 3.36; TA 2.07%; 1.070 gravity (store quality)
2020: pH 3.21; (store quality)
>>> age room temp 1week>> pH 4.13; TA 1.47%; 1.054 gravity.

* basically the TA is high which means that a finished wine with 100% juice needs to be back sweetened
* your pH will be too low on green/ hard to press in fruit. The pH will rise to goal of 3.5 (+/-) and when the fruit is soft easy to bruise it should get some acid correction. For the purpose of pH treat water as transparent and not influencing the pH. With crop on your land you can do the best of both which would be to let some get very ripe (very high aromatics) and then mix back in enough firm/ ready to send to market fruit to drop the pH.
A second way to do this is to mix in a high acid fruit as lemon or rhubarb or tamarind.
* added clean water is transparent to pH (minor change) but has no TA. By the numbers one part of kiwi juice with two parts of water would get the TA in target without altering pH.

My pH is 2.75.. i guess it's gonna be too acidic.. wanna raise pH.. should I add lemon to it?

 

[sour_grapes]

My pH is 2.75.. i guess it's gonna be too acidic.. wanna raise pH.. should I add lemon to it?

No, lemon juice is quite acidic. It generally has a pH of between 2 and 3.

 

[rajeevniro]

2019; pH 3.36; TA 2.07%; 1.070 gravity (store quality)
2020: pH 3.21; (store quality)
>>> age room temp 1week>> pH 4.13; TA 1.47%; 1.054 gravity.

* basically the TA is high which means that a finished wine with 100% juice needs to be back sweetened
* your pH will be too low on green/ hard to press in fruit. The pH will rise to goal of 3.5 (+/-) and when the fruit is soft easy to bruise it should get some acid correction. For the purpose of pH treat water as transparent and not influencing the pH. With crop on your land you can do the best of both which would be to let some get very ripe (very high aromatics) and then mix back in enough firm/ ready to send to market fruit to drop the pH.
A second way to do this is to mix in a high acid fruit as lemon or rhubarb or tamarind.
* added clean water is transparent to pH (minor change) but has no TA. By the numbers one part of kiwi juice with two parts of water would get the TA in target without altering pH.

My pH is 2.75.. i guess it's gonna be too acidic.. wanna raise pH.. should I add lemon to it

No, lemon juice is quite acidic. It generally has a pH of between 2 and

 

[rajeevniro]

So i have acid blend with me but I'm assuming it's gonna further lower the pH .. i guess calcium carbonate would be useful ??

 

[rajeevniro]

My pH is 2.75.. i guess it's gonna be too acidic.. wanna raise pH.. should I add lemon to it

No, lemon juice is quite acidic. It generally has a pH of between 2 and 3.

So i have acid blend with me. But I'm assuming it will further lower the pH making it more acidic. So i guess I'll go with calcium carbonate

 

[sour_grapes]

Correct, you do not want to add acid blend.

Calcium carbonate will indeed raise the pH. However, you should make small adjustments at a time. It is easy to overdo it. Here is a thread with some information. (GreginND is a chemist.): Calcium carbonate?

 

[Rice_Guy]

the pH .. i guess calcium carbonate would be useful ??

Choices
- for where you are calcium carbonate will raise the pH to ideal for yeast, flavor is clean, our down side is that it is slow reacting as it takes several hours to a day to be consumed.
- potassium bicarbonate can be used, it is basically instant reacting, if a lot is used the potassium can give bitter flavor
- you can get a fermentation going at 2.7, your main risk is a stuck fermentation since as CO2 builds up this pushes the pH lower
On my part I would use calcium now to try to get up to 3.0 and hope that it coasts a tenth higher by the time all the calcium reacts. Fine corrections can be done with potassium after the fermentation is finished.

 

[rajeevniro]

Choices
- for where you are calcium carbonate will raise the pH to ideal for yeast, flavor is clean, our down side is that it is slow
reacting as it takes several hours to a day to be consumed.
- potassium bicarbonate can be used, it is basically instant reacting, if a lot is used the potassium can give bitter flavor
- you can get a fermentation going at 2.7, your main risk is a stuck fermentation since as CO2 builds up this pushes the pH lower
On my part I would use calcium now to try to get up to 3.0 and hope that it coasts a tenth higher by the time all the calcium reacts. Fine corrections can be done with potassium after the fermentation is finished.