The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Pineapple Yeast?

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andychrist's picture
andychrist

Pineapple Yeast?

Found an aging half cup of pineapple juice in the fridge, had an aroma of ferment so I warmed it up on the stove top until it bubbled and foamed. Incorporated into another batch of sweet potato dough whose recipe I swiped from Floyd here. As you can see, got good rise in my briouche, nytzels and qaiseroles. 

Wondering now if if my SD starter might be so active because I cultured it using Debra Wink's pineapple/organic rye method. Tenant of mine being treated for Lyme told me his doctor instructed him to avoid any products that could contain yeast, which included pasteurized fruit juices from even freshly opened bottles or cans. So could there be enough living yeast in processed pineapple juice to alter the composition of the wee beasties in a SD culture? Thought that the growing medium determined the outcome, but is it possible that the pineapple introduces a strain of yeast that would not otherwise have been hosted by the rye, and that it could survive and multiply to become a significant or even dominant contender among all the other micro organisms? Would have thought that once it's initial source of food, the fructose in the juice, had all been consumed, the non-native yeast would have petered out. But if it does indeed persist, the subsequent starter might exhibit different characteristics than one begun with plain water. In which case then the pineapple juice has contributed more than just acidity!

Since it matured, I've always keep my rye starter refrigerated and feed it (about weekly) by first stirring in water cold from the tap before mixing in more rye meal until I have double the original volume, then take out half again for new dough and return the remaining amount back to the fridge. Interesting thing is, even cold like this, the starter always foams right up as soon as I stir in the water. Don't recall the simple whole wheat starters I maintained in the [now distant] past responding with such vigor. Which leads me to consider whether some strain of commercial type yeast (which as I understand is bred from fruit sources rather than grains) might have been introduced by the pineapple to my SD. Or do rye starters commonly behave this way? Thanks for any info about this. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

mwilson's picture
mwilson

Too many variables to definitively answer why you're seeing lots of activity. I will say however that commercial type yeast is a by-product of brewing. s. cerevisiae is a top fermenting beer yeast.

I think it was chris319 that was pushing the idea that s.cerevisiae isn't native to grains, which is complete rubbish.

s.cerevisiae is also a wine yeast, it is very common all over the world, even in some SD starters.

PetraR's picture
PetraR

I started my Wheat Starter with grapes, and it worked a treat and my Starter is active and happy and almost 1 year old.

 

mwilson's picture
mwilson

...and you're telling me this because..??

PetraR's picture
PetraR

Why did I reply?

Because I am one of those who used Grapes in there Starters.

But if I should not reply just let me know.

I am quite new here so ....

mwilson's picture
mwilson

You're free to say anything. The question here is the relevance of your input. You replied to my comment but I said nothing about grapes in starters.

So I'm still curious if you have some sort of point...

David Esq.'s picture
David Esq.

"The starter I'm using currently was catalysed with grapes..."

Just saying, she may have anticipated your comment and it would be more interesting to ask how she knew what you were doing without your stating it expressly. :)

PetraR's picture
PetraR

Thank you David Esq.

When he wrote"s.cerevisiae is also a wine yeast, it is very common all over the world, even in some SD starters" I jumped to the conclusion that Wine is made from Grapes and that I used Grapes to help starting my Starter.

Later I wrote that he also used Grapes, but I was not aware of it when I replied.

 

PetraR's picture
PetraR

You wrote :s.cerevisiae is also a wine yeast, it is very common all over the world, even in some SD starters.

Wine is made from Grapes, that is why I replied that I started mine with Grapes.

That was all.

mwilson's picture
mwilson

ok. but still, what is the significance of telling me that you started your starter with grapes?

PetraR's picture
PetraR

Look, if you do not want to understand why I replied than there is no use to continue this discussion any further.

I spend my time doing other things than running round in circles.

I did not offend you in any way but they way you are answering me is almost patronising.

 

mwilson's picture
mwilson

ok. Firstly. I am in no way being patronising. I am asking a question with all honesty. Trust me I want to understand...

I am sorry you feel that way but it's all in your head. 

 

PetraR's picture
PetraR

You wrote in your first post   "s.cerevisiae is also a wine yeast, it is very common all over the world, even in some SD starters."

 

My reply was  "I started my Wheat Starter with grapes, and it worked a treat and my Starter is active and happy and almost 1 year old."

 

 You "s.cerevisiae is also a wine yeast"  "even in some SD starters."

Me thinking: Wine/ Grapes/ My Starter and letting you know that YES it is used in SD Starters, for example in mine.

In a later post you did write that your Starter was made from Grapes and other things.

That was all.

I hope I did explain it now better, if you still do not understand why I replied in the first place...

And with your last sentnece *but it is all in your head * if that is not patronising...

The way you wrote to me so far is as if you talk to a 3 year old , I am 51 years old, I have 4 Children , and do not really need to be spoken to that way.

 

mwilson's picture
mwilson

Thank you for elaborating. I now see where you're coming from. However just because a starter is seeded with grapes doesn't mean s.cerevisiae will exist in the starter. You don't know what's actually in your starter anymore than I do. A starter's microflora changes somewhat over the first few weeks and even months. There are so many variables that influence what microbes that come to thrive.

The most common SD yeast is c.humilis which works in symbiosis with obligate heterofermentative bacteria l.sanfranciscensis. This is the most commonly found and dominant microflora in SD cultures.

S.cerevisiae does exists in some starters it also has a relationship with faculative heterofermentative bacteria l.plantarum. This relationship is often found to be sub dominant.

In particular I was thinking of the SD starter used for altamura bread, where s.cerevisiae is the only yeast found.

The way you perceive my written words is something I have no control over. I absolutely meant no patronisation. I assure you that had we had this conversation in person you wouldn't feel the way you did. When I said 'it's all in your head', it's truth, because it's your perception, you have imagined this feeling of being patronised which I did not put forward. I'm sorry you felt that way. I hope this is resolved now.

 

PetraR's picture
PetraR

No hard feelings, I guess it was a misunderstanding:)

Have a nice day.

Petra

David Esq.'s picture
David Esq.

If one said to you:

You're free to say anything. The question here is the relevance of your input. You replied to my comment but I said nothing about grapes in starters.

So I'm still curious if you have some sort of point...

you might find it offensive, whether said in person or not.

 

mwilson's picture
mwilson

might, no. I wouldn't. It has been said that words make up less than ten percent of communication. Tone and body language are much more significant. Given the choice I would always opt to communicate in person.

feeling offended, stressed whatever are down to the disposition of the individual.

 

David Esq.'s picture
David Esq.

The question is the relevance of what you are saying. 

I am curious whether you have a point. 

mwilson's picture
mwilson

is there a question in there somewhere? Because I'd be happy to answer it if you ask it..

mwilson's picture
mwilson

Imitation is the sincerest form of flattery ;)

cerevisiae's picture
cerevisiae

Google keeps trying to tell me I'm looking for a tree, or a shrub or something. Does the C. stand for candida?

Do you know if Candida Humilis another name for Saccharomyces Exiguus? I recall reading about some confusion regarding the identification of dominant yeasts in sourdough in San Francisco vs. Europe, wherein it was eventually determined that the yeasts were the same, but had been named separately.

mwilson's picture
mwilson

yeah I encountered that search result too. Yes candida. Candida humilis is the most up to date name. Yes it has been saccharomyces exiguous and c.milleri too.

cerevisiae's picture
cerevisiae

Okay. Please include full names at least once next time you're using polynomials in order to avoid such confusion. I've never found a palm shrub in my starter.

andychrist's picture
andychrist

Yes, I see now where bakers and brewers yeast are simply different strains of S. cerevisiae. From what I've read of wine making, the desirable yeasts are anaerobic and do not produce acetic acid. Aside from adding water to my starter first thing upon feeding, I also stir it vigorously. So am guessing some yeast in there must be aerobic, and are responding to the fresh supply of oxygen. Starter does smell pungent, though not really vinegary, at least to my nose. Apparently lactic acid is odorless to humans.

Those starters fed initially with honey, do they maintain different characteristics over time from those begun with just with water in the flour? 

Guess I should begin another new starter without using pineapple juice in the rye, maybe a pinch of vitamin C instead, see how that ultimately compares.

Thanks mwilson.

 

mwilson's picture
mwilson

Yeasts don't produce acetic acid in any appreciable amounts. And yeasts aren't either anaerobic or aerobic they are both. When oxygen is present yeasts will snatch it up.

Lactic acid is almost odourless I'd say. Interesting to note that when a starter is cold and wet it smells like yoghurt, so what does that say...?

I follow Italian SD methods and grow my SD starter aerobically by placing it in bowl of water (my starter is very firm). When you supply water, you supply oxygen. When oxygen is depleted it sours. This method ensures it never sours.

The starter I'm using currently was catalysed with grapes, honey and spelt in aerobic conditions at 30C. For three months it sustained a microflora that caused a banana like aroma. (this suggests a strain of s.cerevisiae was present) But one day of neglect and a trip in the fridge (which it never experienced before) was enough to upset the culture and that banana aroma yeast to die off.

The aroma of your starter tells you a lot about what's going on in there.

Why vit C for the new starter?

 

andychrist's picture
andychrist

Was the banana aroma in your starter some kind of acetate?

Can't really describe how my rye starter smells, other than pungent when cold. When I have a levain going it is very fragrant, smells like fresh baked bread. 

I would use the vitamin C (in the form of FruitFresh) to mildly acidify the new starter without introducing any other sources of yeast, as would the pineapple juice a la Wink.

Thanks again mw.

mwilson's picture
mwilson

Don't know. The banana smell was particularly apparent when it hit sugar and egg yolks. Otherwise by itself the SD had a honey aroma.

Vitamin C is used at 1 part per thousand of flour (1g / 1KG flour) as an oxidiser. At this level it won't acidify your dough. Other acids in fruit provide acidity, eg. citric, malic

What is the goal with the new starter, do you seek c.humilis?

andychrist's picture
andychrist

which is particularly volatile. 

Thats an idea, I could use citric acid. Vitamin C was just one of the ways Debra Wink and friends lowered the pH of their starters right off the bat. Apparantly it worked, but was a job grinding it up — guess they were working with supplement pills. FruitFresh is powdered vitamin C, but the same company also sells citric acid in that form.

Am not looking to cultivate any one yeast in particular, just curious to see whether a new starter made from the same rye and at the same pH as the one I cultured with "fresh" pineapple juice would mature to the same level of activity. The remote possibility being that the pineapple in the original experiment brought something to the table that would not have been found in the rye alone, and that could have persisted through an indefinite number of subsequent feedings. Admit this is unlikely but think it would make a good "control."

mwilson's picture
mwilson

Vitamin C won't lower the pH and makes up only so many milligrams in fruit juices including pineapple. Like I said, citric and malic are the main constituents.

Good luck with your experiments.

placebo's picture
placebo

Unbuffered vitamin C will lower the pH. It's an acid after all.

Debra Wink and friends found that some vitamin C tablets didn't work because they were buffered. Ascorbic acid, which you can buy as a dough conditioner, worked, but they decided on pineapple juice because it was more readily available.

mwilson's picture
mwilson

Yes it's an acid. But it makes up only so many milligrams, whereas citric and malic will be grams in the juice relatively speaking. Citric and malic will be responsible for the lowering of the pH.

If vitamin C is used directly it's done so at 1 part per thousand.

andychrist's picture
andychrist

We are not talking about adding vitamin C to dough as a conditioner, or trying to mimic the ingredients of pineapple juice. Wink and friends were just looking for a a way to acidify starter, period. As Placebo noted, they were basically successful with vitamin C but settled upon pineapple juice for its convenience; just a coincidence that it also happens to contain the vitamin among all its other acids. My point was that while Wink et al were successful in getting their starters to flourish in the acid environment of the chosen juice, there was no discussion of whether any of its other ingredients, including nutrients and dormant or active microbes, might have been at least partially responsible for their success, long term. Which is why I thought it might be interesting to compare a starter acidified with a sterile, non-nutritive agent to one begun with pineapple juice and to track them both over future generations.

mwilson's picture
mwilson

No I understand. But I'm saying that vitamin C won't do anything significant to dough pH. Chemistry is not my strong suit so I understand I could be missing something here, but how can milligrams worth of ascorbic acid effect dough pH significantly?

andychrist's picture
andychrist

You mean there would only be milligrams worth of ascorbic acid in all the vitamin C tablets that Wink et al added to their starters? Forget whether she stated exactly how much she was using but was very clear about the pH they obtained. But perhaps the acidity was not actually due to the ascorbic acid in the vitamin pills, and that they had in fact been cut with citric acid. FruitFresh, which claims vitamin C as it's active ingredient, is likewise so cut. Again, don't know in what amounts; the main ingredient is dextrose. The producer, now Ball, does also offer shakers of citric acid, but likewise I've no idea of the actual amount per serving, assuming it is also diluted with fillers.

placebo's picture
placebo

In their experiments, they used ascorbic acid powder and found that 1/2 tsp added to 4.25 oz of flour produced the best results. That's probably about 2% by weight.

andychrist's picture
andychrist

Thanks for the details, placebo. :)

mwilson's picture
mwilson

Wow that's a lot. That dough or batter is going to be seriously oxidised and so appear very white. Yes at that quantity it will lower pH some.

However if using pineapple juice to lower the pH, it won't be due to the juice's vitamin C content, which is about 50mg per 100g.

andychrist's picture
andychrist

"If vitamin C is used directly it's done so at 1 part per thousand."

If vitamin C is used directly just how and to do what? 

mwilson's picture
mwilson

Vitamin C powder is often used by some bakers and millers to improve gluten. It helps create disulphide bonds.

andychrist's picture
andychrist

But this has absolutely nothing to do with how or why it was used by Debra Wink and friends. :confused:

I do agree however that citric acid could be the better choice as an acidifier, as it is more stable and apparently less disruptive than ascorbic. Do remember from high school chemistry though, my instructor saying how closely related were the two acids and that in nature they are often or perhaps always found together. She firmly believed that citric acid played as vital a role in nutrition as ascorbic, going so far as to predict that someday it would be classified as vitamin C2. Hasn't happen yet. ;-)

mwilson's picture
mwilson

Sure. But oxidation and pH are related. So perhaps this information may prove to be worth something.

Anyway moving away from that subject, which I am not 100% on. I would like to ask why even bother acidifying the dough. The Pineapple juice solution was all about skipping leuconostoc bacteria. But if you ferment above 25C the desirable LAB will outstrip them anyway and your culture will acidify.

Interesting about citric acid. I am very interest in nutrition. Thanks for that. Vitamin C2, maybe one day.

PetraR's picture
PetraR

I started my Rye Starter just with Rye Flour and warm Water and by golly it is one active Starter but not as active as yours.

It takes a bit until it doubles/ trippels but I would say, about 3-4  hours depending on how warm the kitchen is.

My Wheat Starter lives in the Fridge, fed once a week.

I take it out of the fridge, let it warm up and it rises so fast in the warming up period... you can just watch it rising.

I take half out * use it for enhancing my basic white loafe * add water and flour, stir it up, let it start to bubble up , than put it in the fridge.

it might well be your juice you added since you said it was already fermenting.

 

Mini Oven's picture
Mini Oven

on a light yellow plate and the wood table.  It not only looks good, the rolls look scrumptious. :)

PetraR's picture
PetraR

Oh yes, the rolls look very very good indeed, I would love to just grab one and eat. YUMMY