Starting Chemistry for Plum Wine

Hi Everyone,

I'm making my first batch of wine using plums that I grew. Yesterday I mixed up the recipe for a dry plum wine and added everything (per the recipe) except the yeast. I added the proper amount of campden tablets too. I waited 24 hours.

Tonight before adding the yeast tested everything.

Hydrometer read 1.060
TA - 11
PH - 2.79
I wasn't sure I did the free SO2 correctly but I believe it was 18

I've now hydrated and added the yeast. I had thought a bubbler airlock would be used for primary fermentation but the recipe said install the lid loosely and implied no air lock.

Have I done anything wrong so far? Also, the frustrating part about the recipe is that it says nothing about the TA, PH, starting sugar level, etc.

I would really appreciate hearing your comments on what I need to do to get things started correctly here.

Thank you!

Dave

That's pretty acidic! Did you dilute your plums with some sugar and water? Using water to dilute is typically done with acidic fruit like plums.

You could try dropping some of that acid with potassium bicarbonate or calcium carbonate- yeast will have a very difficult time with must that acidic.

Yes I added water and sugar based on the recipe but I just learned that sugar before fermenting controls alcohol level and not sweetness. I wanted to end up around 12% alcohol so I'm going to add more sugar. I'll need to run to the brew shop to get something to drop the acidity I guess. Thank you for the suggestion and help!

Does acid blend affect the TA level at all? If it does, maybe the recipe had me put too much in.

dbeck said:

Does acid blend affect the TA level at all? If it does, maybe the recipe had me put too much in.

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Yes- it definitely does. Probably the correct amount would have been 0, and then added to taste after fermentation if needed.

Makes me wonder why the recipe called for acidic blend. Seems like you should only use it after testing

dbeck said:

Makes me wonder why the recipe called for acidic blend. Seems like you should only use it after testing

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Yes, but many people want "winemaking by the book" steps, and I guess maybe storebought plums wouldn't be as acidic. My wild plums are more acidic than any other fruit I"ve ever used, so I wouldn't use it in my recipe.

How did you derive TA and pH? Unless you're using some (admittedly very basic) lab equipment, the home test kits can vary pretty wildly. It's OK and I advise you to press on, but think about yeast considerations as many will have trouble with that low of a pH and high TA. Adjust with some potassium carbonate (not too much) to try and reverse the acid blend addition a little and proceed with fermentation. See how it turns out.

DEFINITELY DONT MALO ewither, it will turn your plum wine into a buttery weird mess. Here's some help with additions, you may have to do a little conversion to scale down to your batch.
http://wine.wsu.edu/research-extension/2010/10/managing-high-acidity/

My first wine was a "wild plum" but turned out to be a damson plum. But same difference. There small and strong unlike a store bought plum. The recipe I used didn't call for any acid blend. But the recipe was for a wild plum because at the time I didn't know what kind of plum it was. Its funny on the type of plum, apple,or pear, ect makes that big of a difference. I actually just did a little story about "my first" on the drunken ramblings thread. It was a plum. Check it out if you have a min. Might find it amusing. Its titled" how it begun". Just hope you don't plan on giving them as x ma's gifts. Hahaha

I followed the recipe which said to add acid blend. Knowing what I know now I would not add acid blend without first checking the TA level. I'm rather annoyed that the recipe didn't make it clear that it should be "add as needed" rather than just add X amount.

I use this test kit to check TA Eventually I'll be buying an electronic tester and have a lab for all this stuff.

I may start a new batch of plum wine in case the first one goes bad on me. I did add calcium carbonate and it seemed to bring the TA down some. But I absolutely do not understand the directions on how to add the calcium carbonate. And I understand everything I read so they must have been badly written. I ended up putting a few measured spoon fulls in some water and stirred it up and added it to the must. But I would like to know the proper way to do it.

dbeck said:

I followed the recipe which said to add acid blend. Knowing what I know now I would not add acid blend without first checking the TA level. I'm rather annoyed that the recipe didn't make it clear that it should be "add as needed" rather than just add X amount.

I use this test kit to check TA Eventually I'll be buying an electronic tester and have a lab for all this stuff.

I may start a new batch of plum wine in case the first one goes bad on me. I did add calcium carbonate and it seemed to bring the TA down some. But I absolutely do not understand the directions on how to add the calcium carbonate. And I understand everything I read so they must have been badly written. I ended up putting a few measured spoon fulls in some water and stirred it up and added it to the must. But I would like to know the proper way to do it.

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I go to Jack Keller for all of my winemaking questions. His site is awesome, although sort of hard to navigate at first. Lots of "stuff" to wade through and find, but it's a real gem.

If you start here: http://winemaking.jackkeller.net/advbasic.asp and scroll down you can find everything a bit easier.

In that list is "acidity", and here's that direct link: http://winemaking.jackkeller.net/acid.asp Scroll down (again!) through about 1/2 that page to get to the part about increasing and decreasing acidity.

One can easily lower acidity in a finished wine through additions of calcium carbonate, acidex, or potassium bicarbonate, or through cold stabilization.

Calcium carbonate reacts preferentially with tartaric rather than malic acid, so one should not try to reduce acidity more thab 0.3 to 0.4% through its use. A dose of 2.5 grams per gallon of wine lowers TA about 0.1%. After its use, the wine should be bulk aged at least 6 months to allow calcium malate, a byproduct of calcium carbonate use, to precipitate from the wine. The wine should then be cold stabilized to ensure tartrate crystals do not precipitate out after bottling.

Potassium bicarbonate is used to deacidify a wine with a low pH (below 3.5), but should not be used to reduce acidity more than 0.3%. A dose of 3.4 grams per gallon of wine lowers acidity by about 0.1%. After use, the wine should be cold stabilized, as up to 30% of the potential acid reduction occurs during cold stabilization. It will cause a greater rise in pH than calcium carbonate for an equivalent reduction in acidity.

Finally, potassium bitartrate (a.k.a. Cream of Tartar) is used as a catalyst to help promote cold stabilization. It promotes the formation of tartrate crystals and is used at the rate of 2 to 5 grams per gallon, followed by vigorous stirring. Its use results in better and quicker stabilization, and these benefits will occur at slightly higher temperatures than without it.

One thing to keep in mind is that if fermentation gets going, you don't have to worry too much about the pH at that point. The danger is for the must to be so acidic that fermentation won't happen- yeast are pretty tolerant but can't function in a too acidic environment. After fermentation, cold stabilization can make a huge difference in grape and plum wines in reducing the acidity. I've had that experience- puckeringly tart native grape wine or plum wine is so much better in a year, after some of the acid drops out.