Keep the air space to a minimum by topping up with a similar red wine.
Excess oxygen will spoil your wine. Adequate levels of sulfite will
help prevent over-oxidizing your wine but cannot prevent the wine from
spoiling if it is exposed to excess headspace for a long period of time.
You should definitely avoid water for the reason you have
experienced. It is rarely desirable to dilute wine, often desirable to
concentrate it such as in barrel ageing.

You can also rack into a series of smaller containers but that can be a
nuisance at this point. Most winemakers try to make wine in quantities
that are a little more than the volume of their secondary carboy(s) and
keep 10-20% in smaller containers for topping off after racking.

Leaving too much headspace for a significant amount of time will cause
oxidation of the wine and both reds and whites will take on a brownish
tone and a distinctively bad taste, usually making the wine undrinkable.
Once a wine is over-oxidized I am not aware of any practical way of
reversing it. Exposing a wine to excess oxygen is probably one of the
most common mistakes made by beginners and even experienced winemakers
who might become a little sloppy.

Good luck,

Glen Duff


Tom S wrote:

> "santos" > wrote in message
> ...
>
>>I just finished racking 2 carboys of red wine and have none available to
>>
> top
>
>>up with and would like to top them without having to add water, as I tried
>>that in the past and ended up with a weak result... I do have some white
>>wine that i can use easily, but I am wondering if it will effect the taste
>>much? or if there are any other reaosns it would not be suitable? At
>>
> worst
>
>>I'll break down and buy a bottle of red tommorow but with the white being
>>ready at hand seemed like an easy fix... any suggestions?
>>
>
> Go buy some similar red wine and top up leaving no headspace. If you're
> using a rubber stopper to seal the carboys, leave a _little_ headspace, but
> be sure your free SO2 is up where it should be.
>
> I rather like the pop-off plastic caps that come on carboys of bottled
> water. You can top completely full, and not worry about thermal expansion
> blowing the bottom out of a carboy.
>
> Tom S
>
>
>