The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Dough PH to keep mold away?

nicodvb's picture
nicodvb

Dough PH to keep mold away?

Hi,


is there a PH for the final dough (before baking) that can guarantee that the baked bread will be protected from mold in the long term?


I know that the maintenance of the bread is equally important, but surely the acidity level has its share of importance.


I remember that Hamelman wrote of having sent small packages of his rye bread the the various stages of his travel by bike and that none of his packages was attacked by mold.


My rye breads keeps for 15 days, but I'm aiming for a longer period.


Thanks.


 

Ford's picture
Ford

Yes, the higher acidity (lower pH) of sourdough bread contributes to the improved "keeping quality" of the bread, including detering "mold" formation.


The reference to Hamelman's trek is found on page 201 of his book "Bread ..."


Ford

sphealey's picture
sphealey

Well, nothing will guarantee that bread doesn't get moldy; for example if you live in a humid climate downwind of a mushroom farm I would't expect it to last for more than a day no matter what the pH ;-)  But in general I find that loaves made with all bakers yeast go bad in about 2-3 days (although they may have dried out before that), those made with sourdough boosted with bakers yeast last 3-5 days, and those made with all sourdough (no bakers yeast at all) can last 5-9 days (although by day 7 or so they aren't good for much except altus brat or bread pudding, but they haven't gone bad).


Hamelman reports making volkornbrot and similar very acid ryes that lasted for 30 days when he was hiking the Long Trail, but I have never really wanted to test that theory!


sPh

ananda's picture
ananda

Nico, you really do ask the most interesting and challenging questions in your forum topics!


Here's a few notes to help you along for now.


Interestingly, I have more experience of "shelf-life" issues of this sort in the context of both cakes and biscuit, rather than bread.   I suppose this is pretty self explanatory.   Bread has a short shelf life, and the general consumer test [sad to say] would be the "squeeze test" for the wrapped and sliced monsters on the supermarket shelves.


However, no one wants to eat a soggy biscuit, or see mould growing atop a wrapped cake of any description.   And the shelf life for these confectionery items is considerably longer.   For biscuits, the main checks are carried out as the biscuits exit the travelling ovens used to bake them.   Very careful checks are carried out, particularly in relation to the residual moisture in the biscuit.   For cakes, again, the residual moisture is a key part of the data gathering.   Additionally, the ingredients are all analysed for their sucrose equivalence [SE].   This is the key to determining the amount of "free water" left in the product.   Reference to a pre-calculated table enables food manufacturers to combine the known sucrose equivalence in a product, with the residual free moisture, to ascertain what is known as MFSL [mould free shelf life]   These calculations are carried out to establish the ERH [equilibrium relative humidity] in a wrapped cake product.   This simply means the point at which there is sufficient moisture in the gap between the top of the cake, and the wrapper itself, to cause mould to grow.


For breads, yes, Hamelman does make some useful remarks, as noted above.   I am pretty sure also, that some posters on TFL recommend keeping all-rye breads sliced and wrapped in the fridge.   Don't quote me on this, but I'm thinking Mini, or, maybe Karin?   For sure, a cold temperature will inhibit mould growth, and, so long as the bread slices are wrapped sensitively, this seems like a good way to go.


It is, of course, perfectly possible to calculate the residual moisture in your rye loaves too.   Weigh your baked and cooled loaves.   Take this figure from the scaled weight of the original dough pieces to give you the full weight lost.   Then take this figure away from the original moisture content in the dough.   This should tell you how much moisture is left!


I'm nort much help beyond this, but feel sure this may have been addressed in academic papers, or maybe even by Debra, you never know.   I suggest you look at the list of favourite posts I have and see if you can find such references.   The link is here: http://www.thefreshloaf.com/user/ananda


all good wishes


Andy

nicodvb's picture
nicodvb

Hi Andy,


I see there are a lot of parameters that the industry keeps into account to prevent the formation of mould.


I regularly calculate the residual humidity of my breads, but there's not a single value that gives me an indication of the amount of residual moisture to pursue: sometimes mould stays away in very moist breads and sometimes it aggresses quite stiff and dry ones.


Well, rarely I do the same kind of bread because I like experimenting a lot, but I can't avoid to feel a certain imprevedibility in my breads.


By the way, I've just sliced my last rye bread made hot soaker, multiple fermentations and  18 hours of baking. A chocolate cake with malt aroma ;-)

hanseata's picture
hanseata

As always, it's a pleasure to learn something new from you, Andy!


But no, it wasn't me who recommended keeping bread in the fridge. Since I like fresh bread best and we are only two people, I usually freeze half of my loaves.


Fresh bread I keep in a brown bag or wrapped in aluminum foil (if it is Vollkornbrot). It usually dries out rather than getting moldy.


Karin


 

Yerffej's picture
Yerffej

Karin,


Why do you wrap Vollkornbrot in foil?


Jeff

hanseata's picture
hanseata

I read it in WGB and thought it would keep it a bit more from drying out. Vollkornbrot is not one of my most favorite breads, therefore it usually lasts longer than others. But I have to admit I don't really know whether it makes a difference.


Karin


 

Yerffej's picture
Yerffej

Thanks Karin,


In this house Vollkornbrot has a very short life and preservation is not an issue.


Jeff