bitter taste.please help

[matmar6974]

hello everyone.Sorry for my english.I'm from greece and i distill grapes this year.The result is raki but its some bitterness.Anyone some way to remove this.I mean li add something and i distilling again?Please some solution.

[blanikdog]

G'day Matmar. Don't worry about your English, it's fine. You haven't given us much to work on. Can you tell us more about your still and what you used to get the Raki flavour?

blanik

[matmar6974]

First,i crach the grapes and push for their juice (all these with my family hands).From this juice we make wine.Then i put everything else maze in a pot and i'm waiting about 20-30 days.Then distill with a small pot still -maded from me- from a cook pot -you know,there we cooking very fast and is stainles.Nothing else.No sugar no yeast.The product is very fine and healthy,with measure ofcourse.Is better fresh and does not need aged -old.Personality i'm speeking only for 100-150 kgr(50-70 pound?) grapes.Only for my pleasure.And this is my second distill time.Thank's.

[CletusDwight]

So, you are making wine from grapes then you put it in a stainless steel pot to distil it.
And I guess you must have a condenser to turn the steam back into alcohol.

When you distil the wine, are you taking all of the alcohol? or are you separating the first part and the middle part and the last part? This is what we call making 'cuts'. Not all of the alcohol is good to drink. Some of it tastes bad and some of it is even a little bit poisonous.

[matmar6974]

I have a small potstill with condeser who cooled by water and all these stuff.I distill in three stages.Head-heart-foreshot?The bitter taste is in all stages (i'm trying it all the time) and something smell bad.When i distill second time the smell remove but taste is still bitter.I'm thinking if the man who sold me the grapes took them some sulphur.I was ask him but some of them are liers.Is sulphur or some same problem for distillation?there is a solution?

[Dnderhead]

copper will help take out sulpher.

[blind drunk]

So, you are making wine from grapes then you put it in a stainless steel pot to distil it.

Sounds more like he makes wine and then uses the left over skins and seeds to make his hooch.

Hey matmar, did the bitterness happen the first time also? bd.

[matmar6974]

No!In really,the first time was exellent.If i understunt correct,i must distill again with copper?Like clean copper tubes in the pot-distill?

[CletusDwight]

We are making guesses at the problem.
There are many possibilities.

Sulphur can be a problem sometimes because sulphur compounds are used to sterilise equipment and sometimes the grains we use can contain small amounts of sulphur compounds. Copper will remove small amounts of sulphur compounds from the alcohol vapour because it forms black copper sulphide very easily.
But if you have a lot of pure sulphur in the wash, that is a more serious problem. You may be getting hydrogen sulphide, which is a very poisonous compound.

If there was sulphur in the grapes though, I would expect it to kill the yeast. Did it ferment OK?
How does the wash taste? Like a dry wine? or does it taste of something else?

I would not use something to make alcohol if I was not certain it was clean. There are plenty of cheap grains and fruits that you can use instead.

[matmar6974]

We don't use yeast.The ferment was ok for 30 days,from nature grape yeast, but i did not try the wash before distill.I'm a beginner.Well, you think that all this hapents becouse the wash become vinegar?Anyway thanks all for your attension.

[Dnderhead]

was stems removed? did it burn in the still?

[matmar6974]

Yes,the stems are removed before fermentation.But we don't remove the grapestones.

[CletusDwight]

We don't use yeast......from nature grape yeast

Sure you did - you used natural yeast.

It helps to taste your wash before and after fermentation so you can tell everything is OK.

[kazanas]

Hi matmar, I'm from Greece too
Check if the rubber in your pot, is burned
check if the grapes on the bottom of your pot are burned from a strong fire.

[Dnderhead]

your making "grappa" tends to turn out bitter, do to tannens, fiend some grapes that are not prest . just juiced as they make
whight wine.

[bstinga]

These are comments by Dr. Clayton Cone of lallemand that may also help;
"Harsh and bitter sensory properties are enhanced when the juice or must is deficient in micronutrients such as pantothenic acid.
Too little juice nitrogen will "starve" the yeast during the fermentation. The result is usually poor yeast cell growth leading to stuck and sluggish fermentations as well as negative sensory impact."

So the bitterness could be reduced if you add a balanced amount of nutrient to the fermenting batch. It is most beneficial to add these in stages, i.e. total amount of nutrient divided into at least 3 doses throughout the first half of fermentation.

You may also wish to kill off the wild yeast and bacteria and then try a commercial selected yeast strain that does not impart much flavour etc.

Wild yeast is known for this aroma is often associated with what some describe as 'phenolic'. Also from Dr Cone.... "This is somewhat a catch all for a number of compounds usually associated with wheat beer yeast, many Belgian yeast strains and wild yeast. The compounds can vary in strength and character depending on the strain itself or how it is handled. This would include temperatures and, aeration levels. Some of these yeast have relatively high levels of phenylethylene, a plastic resinous like odor, like the synthesized compound known as styrene..... Whether from a known wheat beer yeast strain or a wild yeast, the relative levels of these compounds vary and can be perceived quite differently. I find phenolic compounds from wild yeast and bacteria to have a much different (undesirable profile) as compared to German style wheat beer strains and many Belgian yeast strains."

Also killing off any wild bacteria before inocculating with a selected yeast may reduce the by products (acids etc) of these bacteria during a ferment.

What if any spray was used with the grapes, these are often copper based but maybe had some sulphides? Good luck with the next batch of Grappa! Keep us posted.