R
Since you seem to have already grasped the basics of how
to go about this, I will try to give you a_very_shorthand
version of how to calculate for such a recipe.
1. Estimate where the yeast you are using will "end". eg.
The maximum alcohol tolerance of that yeast.
2. Figure out how many "gravity points" of sugar it takes to
achieve that amount of alcohol. Write it down. Example:
It takes ~105 gravity points of sugar to produce ~14%ABV.
3. Decide what your "as indicated" target_end_SG will be.
Example: If your target is say 1.020, write down 20.
4. To compensate for the effect of alcohol on post pitch SG
readings, write down 12.
5. Add these three numbers. In this case it is 137. This then
is where to set your OG. eg. 1.137.
6. If the yeast actually "ends" at 14% (it's seldom exact) you
should end up very close to your target end SG. If it is
higher than your target, it means the yeast didn't produce
the expected amount of alcohol, and if it is lower it means
the yeast produced more alcohol than expected. The only
way to refine this further is by empiracle data for individual
yeast/recipe combinations.
You have to get pretty deep into this stuff to start using "gravity
points of sugar" to calculate things. Most folks just use the
"as indicated" end SG/Brix reading to determine RS. Which
is perfectly all right except it fails to recognize the effect of
alcohol on post pitch SG readings.
I think I better stop there. The last time I tried to explain this,
the discussion went off on so many tangents that I couldn't
keep up with it all, and I actually got flamed so bad I had to
give up posting here for a couple of years. I do NOT want
to get all that started again !! HTH
Frederick
"AxisOfBeagles" > wrote in message
...
> Thank you Frederick - that's more the kind of feedback I was digging
> for. Especially appreciate your SG relative to sweetness listings - I
> usually judge that by residual sugar, but it's more helpful at this
> stage to estimate it by SG. Thanks.
> I went ahead and started the wine (recipe #2 - the sweet wine) day
> before eyesterday. I first pressed out a bunch of plums and ran tests
> against that juice (SG, TA, pH). I then tinkered with the amount of
> sugar to achieve what I hoped would be a satisfactory residual sugar
> (after first selecting a yeast that has an alcohol tolerance opf only
> 14%). I did adjust acid (tartaric).
> It's fermenting away now, and I'm testing the SG twice a day.
> Somewhere around halfway down I'll test taste and acid again and make
> any final nudges one way or the other. Then cross fingers.
> Intersting ancedote: the plum juice has considerable titratable
> acidity - 1.1, but a high pH - 3.97. After adding sugar and water,
> then adjusting back with tartaric acid, I was able to get the acidity
> into more 'normal' ranges for a wine --- .85 TA, and 3.49 pH. We'll
> see how those numbers look at the halfway point and again after
> primary.
> R
>
>
>
> In article >
> "frederickploegman" > wrote:
>
>> Ax
>>
>> The second recipe on Jack's site is a kind of "old fashioned"
>> recipe for a sweet wine. Trying to design such a recipe "by
>> the numbers" can get very complicated indeed. Most folks
>> can't handle it or just don't want to be bothered. In the old
>> days this was done by trial and error rather than "by the
>> numbers".
>>
>> The easy way is to use the "modern" method. Make the first
>> recipe there. The dry one. Original pH ~3.6. If no Tartaric
>> acid is used, the pH will drop during the ferment. If Tartaric
>> is used, set original pH at <3.5. OG ~1.090-1.100. You
>> need this little bit of extra alcohol because adding post
>> ferment sugar will dilute the wine and you don't want the
>> end alcohol to drop below 10%ABV. Use a strong yeast
>> such as P. Cuvee to insure it goes bone dry. Ferment and
>> clear. Add sorbate and sweeten to taste. Take an end SG
>> reading so you know what your perference in sweetness is
>> for future reference.
>>
>> There are lots of kinds of plums and not all of them are
>> created equal. For older recipes you can usually "assume"
>> they are talking about the prune plum. If you have some
>> other kind, you will have to guesstimate the quantity needed
>> for the flavor intensity you want. Start with the recipe as
>> given and see how it turns out. HTH
>>
>> Frederick
>>
>> PS - FWIW. An old sweetness scale that I used to use
>> went something like this:
>>
>> 0.990 to 1.000 was the dry to off dry range.
>> 1.000 to 1.008 was the medium dry to medium sweet range.
>> 1.008 and over was the sweet range. Late harvest type
>> wines generally run in the low teens. Port style wines in the
>> mid 20's. Ice wines in the low 50's. And some kosher wines
>> well up into the 60's.
>>
>> But, bottom line, it's still like asking "...how sweet is sweet..."
>> HTH
>>
>>
>>
>> "AxisOfBeagles" > wrote in message
>> ...
>>> Appreciate the responses - but maybe I was unclear. I was looking
>>> for any metrics for a sweet (dessert) plum wine that others may
>>> have; what ideal sugar levels should be; what acidity should be;
>>> etc. I can measure these things, but neither the recipe, nor my past
>>> grapes winemaking experience give me any insight as to what the
>>> target numbers should be a sweet plum wine.
>>> Thanks for any suggestions.
>>>
>
> --
> I'm using an evaluation license of nemo since 49 days.
> You should really try it!
> http://www.malcom-mac.com/nemo
>