Fining & Astringency

[Guest]

I'm looking at dealing with toneing down the astringent bitterness of my 6 gal. Blackberry I'm in final fermentation with.


I read in WineMaker Mag that using egg whites (and the inherant albumen), will soften astringency and mellow the wine with no negetive residue or effects and will aid in fining.
Since it's a bit more natural than a chem base solution, I'm tempted to try this.


Has anyone else tried this technique and what were your results?


Mike

 

[grapeman]

Something you could try first if you haven't used a lot of sufites yet would be to introduce a malolactic fermentation in it(MLF). Blackberries can have a lot of malic acid in them which is a sharp acid and may be what you are perceiving as astringency. The MLF converts the malic acid to lactic acid and reduces the overall acidity of the wine. I leaves it with much smoother edges. It it very similar(and probably related to) to the Buttery Chard method in the finished product. George sells vials of White Labs liquid malic acid bacteria. You just add it to your wine(no more than about 10-20ppm free S02) put in an area about 70-75 degrees and leave it there until the tiny bubbles cease to form. You can do an Accuvin test for Malic acid to see if it is done yet.

 

[Dean]

The easiest way to test if it is highly acidic, is to take a glass, and add small amount of sugar unti it tastes good. Because acid is sour, and sugar is sweet, they serve to balance each other out. If the wine becomes too sweet, you can look at trying some precipitated chalk to take out some acid, try cold stabilization (works primarily on tartaric though), and also try MLF. Get a paper chromatography kit to test for malic acid. If it is in the high range, then MLF will soften the wine much better than chalk will.

Or, you could backsweeten to balance it all out.

 

[Dean]

oh yeah, one last thing. Egg white fining strips a wine of harsh tannins, and does nothing to reduce the acidity. Blackberries are not high in tannins, so it would be unlikely you have a highly tannic wine. Thus, egg white fining would not do this wine much good.

 

[Guest]

I've read all this info about being gentle in the pressing of the fruit in order to not damage the seeds or skins to the extent that they leeched more Tartaric Acid to the must.


Being that I used a Vintners Harvest, Fruit Base, the material came to me in two 96oz. cans with about 1/3 fruit and the balance, juice.
I bagged the material for straining purposes and shortly before fermentation ended, I pulled the bag, squeezed the dickens out ofit with my hands and then twisted it up as tight as I could turn it to removed as much of the juice as I could.


Did I perhaps, in the process of this, use too much force and as such, leech the Tartaric Acid I didn't want?
Mike

 

[grapeman]

It is unlikely you squeezed too hard unless your name is Superman. Chances are very good it is Malic Acid, not Tartaric Acid. The MLF would reduce overall perceivable acid by turning the Malic Acid to Lactic Acid. You could also do like Dean says and try to balance with sugar after stabilizing with K-Meta and K-Sorbate. If you do that FIRSTt-DO NOT ATTEMPT MLF. If you want to do MLF, don't add the K-Mata or sorbate untill after MLF is complete.

 

[Guest]

Already added 5 crushed campden tabs.
Guess that sorta narrows my choices huh.
I'm figurin on settin on this till after the holidays and adding more water and sugar to see what happens.
Might treat myself to an acid test kit as well just tosatisfay the curiosity of the Mr. Wizard in me.

 

[OldWino1]

I am asking this question would some of the glyserin sweetner help out?