Mold Growth in Pie
Question - we are a small bakery that manufactures RTE pies. We do annual shelf life testing on on our pies (we do a combo of fruit flavors, pumpkin, and some chocolate/pecan pies). We did two tests on the product - for mold/yeast on day 1 of their shelf life, and mold/yeast on the last day of their shelf life. But our mold results are much higher on the first test than on the second test. For instance, our apple pie had a mold count of 30 cfu on the first day of its shelf life, and 10 cfu on the last day of shelf life. If mold is growing in the product shouldn't the second test be higher? How is it lower?
Any idea how this can happen or what we can do?
Theoretically it isn't growing, it is being killed off by low water activity or some other physical property of the product. That doesn't mean nothing will grow, or that other types of yeast or mold wont grow, but the the types that test is looking for could be inhibited.
Or there was just some kind of sampling or lab error. Or perhaps the limit of precision/accuracy of the test technically means 10 and 50 are the same result.
Got it - that makes sense. But do you think an auditor will have an issue with these results, given that the initial tests show mold that is out of our limit? We want everything to be under 10ppm.
Got it - that makes sense. But do you think an auditor will have an issue with these results, given that the initial tests show mold that is out of our limit? We want everything to be under 10ppm.
If you released product that was out of specification, yes a food safety auditor will have an issue with it.
I'm not a pie expert, but <10 CFU / g or essentially no mold might not be a realistic specification.
Hmmmm. Can any other pie bakers share their mold limits? We've never had a problem with our pies molding on the customer end.
I also know little about pie, other than stuffing it in my face, but that seems really low to me too.
Well that's helpful, hah hah. I've searched these forums before but it's hard to find stuff about specific limits for pies or fruit-filled pastries. If we set the limit at, like, 100 cfu we'd be well under the limit.
Well that's helpful, hah hah. I've searched these forums before but it's hard to find stuff about specific limits for pies or fruit-filled pastries. If we set the limit at, like, 100 cfu we'd be well under the limit.
I don't know the specifics of your product or process, but 100cfu is probably a more reasonable limit. You could be hard pressed to find less yeast/mold than that in the air you're breathing in many places or times of the year.
Thank you! If anyone can share any academic studies that I can use to support this limit please share! I have searched through these forums before but never found what I was looking for.
Thank you! If anyone can share any academic studies that I can use to support this limit please share! I have searched through these forums before but never found what I was looking for.
This link may interest you.
As for the difference between start and finish, it seems like this is just experimental error/slight deviations between samples.
If you tested the SAME pie 10 times you could easily get results like 10,30,20,10,30 etc. That's just the way of micro Testing, you tend to get a bit of variation .
I would conclude that the end of life result is OK. 😌
Hope that helps
Hi jennah20,
As per previous posts, the difference between 10 cfu & 30 cfu is not statistically significant. Typical methods indicate a count of between 30 and 300 on a plate are required to gain an accurate result.
A target of <100/g is reasonable, especially at and of life.
Kind regards,
Tony