From the Winemaker 第3回 ワインの添加物について(原文)

Winemakers Article Version # 3

September 2015

This newsletter will be focused on wine additives, as there has been a bit of interest in this topic.


We will go thru the following additives


  • Sulphur Dioxide


  • Bentonite


Ok, Sulphur Dioxide also known as SO2, so we will use this format throughout this topic section. SO2 has been used in the wine industry for hundreds and hundreds of years, it is still the only method known to man to prevent any unwanted yeasts and bacteria from growing in wine.



In general, unless you are an asthmatic it will not harm you, quantities used are quite low and it is also depending on pH of the wine, colour and if the wine has any residual sweetness.


We first start to use SO2 in the vineyard for spraying the vines against powdery mildew and also mites, again in low quantities, but is does get rid of these fungal vine issues.



The real next period is when the fruit is being harvested, we will add it to each of the picking bins to prevent any squeezed out juice fermenting or trying to start fermenting.


We work off a % of SO2 loss when adding and it really is divided into 3 parts, a loss, a FSO2 and a BSO2.

次にSO2の使用の目的は1)使用量の低下で加える場合 2)FSO2 3)BSO2 の3つの工程で使用する様、分配をパーセンテージで分けます。

FSO2 is what winemaker need to keep the wine and or juice clean and fresh, and non-fermented state.


BSO2 is called bound, this is the balance that it not loss, nor FSO2 and mostly BSO2 is attached to colours, sugars and also flavour compounds.


The total of the FSO2 and BSO2 is called TSO2 or total SO2 added in the wines, this is like a register of total SO2 added to a wine, so we do have limits and can’t hide that fact.

このワインに加えられるFSO2BSO2の総称をTSO2Total SO2と呼び、ワインにどれ程のSO2が加えられたかを明確に記す必要があるため、私たちは出来る限り最小限に抑えて使用しています。

Once the fruit is at the winery we will add more to the crushed fruit for whites at the crusher, we need to have a level of at least 15mg/lt FSO2 in most juices with the temperature being around 12oC.


We ensure that the level at the white juice stage is not too high, we need the natural yeast or the cultured yeast to work, and too much FSO2 will prevent this, so a fine line is used.

Once fermenting the FSO2 is virtually 0 and that is ok.



Once the wine is finished fermentation, wines are checked for o sugar levels and then chilled and then more SO2 added to increase FSO2 to at least 35-45mg/lt.


In general, is a wines pH is high, then we must use more SO2 to allow us more protective SO2 working in the wines to prevent oxidation, retain freshness and also prevent at onset of bacteria growth and wine damage.


Most wines will always go into full sealed tanks, otherwise you will have the SO2 working to remove the O2 in the wines and creating H2O2 in the process, this will lower the level of FSO2 in the wines and more will need to be added.


No oxygen in wines or tanks and FSO2 will be stable.

Wines that go to bottling will be also around that 35-45mg/lt.


We now will look into the use of Bentonite, this is a clay like substance, powder and dry, and when we need to use it, we must add ten times it weight in water @ 80oC to allow the bentonite to swell up over 24hrs period.


The real benefit of bentonite has to main uses, firstly used just after a white wine is finished fermentation and it has be racked and SO2 added and placed in a full tank, we will normal add bentonite to the wines to allow yeast clarifying of the wines.


At this stage we need to get the wines clarified ASAP and this is the best method. We would normally add 0.25gm/lt and leave it sit in the white wine tanks for approx 6 weeks.


Once added it will attach itself to the yeasts and make the heavy and intern they fall to the bottom, then this allows finer materials left in the wines to also allow sedimentation to occur and in general wines will became clearer and we can then make informed decisions about tasting directions and also blending options, as the wines are clear and yeast impact on the palate at this stage is quite low.


Once wines are clear and blended and tasting approval signed off on, we will then stabilise the wines for excess protein in the wines, this is important, and if we do not remove the excess protein then if wines become heated in any fashion over the 40oC+, the wine protein that are in solution will become denatured and for a haze in the wines and in some cases a deposit and doesn’t look to good to the customers.


We do a lab trial to work out how much unstable protein is in the wines, we do this with a 10% bentonite solution, when we have the correct sample with no haze and it is clear post heating, we will add that amount to the wine in tank, and this will create a protein stable wine. Should wine be then subject to excess heat, the wines will not go hazy or create any further deposits.

Hopefully I have either confused you more, or maybe made things a little bit clearer.





Until next time see ya














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