Bitterness in semi-lactic set surface mold ripened cow's milk cheese

[DrsFolly]

Does the size of the cheese make a difference in the likelihood of bitterness developing in a semi-lactic set surface mold ripened cheese as it ripens?  We are using standard rennet set camembert molds 104mm ID.  Would we have better luck with a smaller mold?  A larger mold?

What about surface coating of ash?  Does that change the ripening process in a way that would avoid bitterness? Slower? Faster?

[awakephd]

The thing most commonly associated with bitterness is the amount and/or type of rennet.

Too much rennet of any type can result in bitterness (or so I have read; I have fortunately not experienced it myself)

Vegetable (thistle) rennet is more likely to be bitter than animal rennet (again, so I have read; I've only ever used animal rennet)

Do either of those sound possible as a cause?

I seem to recall reading something about too much CaCl as another possible culprit - not sure, as it's a fuzzy memory (as more and more of my memories tend to be!)

[DrsFolly]

For a 25gal batch we use 8ml single strength rennet.  It goes in about 4hrs after the cultures go in.  The amount of culture varies during the milking season but we try to hit ta 0.59 at moldup the next morning.  Animal rennet.