I'm a chef with 30 years of experience, including pastry. I
meant I didn't understand the sentence.
>
>

Well..
.. I worked in the food industry for decades and I know how chef's
think....in my observation they are good cooks and know how to manage
the kitchen but not competent enough to think ..in scientific fashion
..and sometimes forget to implement food safety procedures ..in their
day to day chores..
Just think about this, after years of training, experience and even
schooling, occasionally food poisoning still occurs...in their
kitchen...


>I had my first restaurant job in the early 1950's when I was in grammar
>school. I started my first restaurant in 1974 and have owned several
>others since; I've run country club and resort operations, and consulted
>about all phases of foodservice. I'm also a published food writer.

So with all that experience ...do you think that you are already
qualified to talk about HACCP?
Besides
What does being a food writer have to do with food safety rules...?
Food journalists who are also chefs a....IMO (and even from
observation in some certain chefs who become writers ) .usually focus
on English composition and grammar than the food safety in their
kitchens...
During your formative yearsin the kitchen I doubt if such NASA derived
food safety rules did ever came to the minds of your mentors....and if
you absorbed the habits of your traditional teachers ...its unlikely
that you will change instantly due to changing trends...in food
processing rules.. I had met and seen so many chefs in my career ....an
its often that in the old and highly experience chefs ,old habits
are difficult to change specially for high ranking chefs that have
egos as huge as a blimp.<grin>..


>> Pickles are a good example of foods with high water activity that
>> can safely be stored at room temp. The combinations of pH, water
>> activity, preservatives and processing are the determinants.

> Pickes?....bakers and pastry cooks don't deal with such items.... .

>Understood. But for room temp storage, it's not just water activity that
>matters, even for pastry.

Pastry?....yes they had lower moisture content and so have lower
water activity values compared to cakes and bread due to the high
amount of fat but they are still susceptible to spoilage..for example
....the .pastry casing is for meat pie but even when baked it does
not prevent it from getting spoiled ...Meat filling juices may seep
into the casings cracks and crevices increasing the moisture content
and hence the water activity....

> Cheeses and eggs provide opportunity for
>bacterial and mold growths, for example.
>
Cheese and eggs used in general cookery usually results in moderate to
high water activity in the finished products , aside from the fact that
they provide an active culture media for microbes .... because of that
pathogens can live and multiply in them.......compromising food safety
of the finished food item.

>Fruit curd fillings generally have a reasonably low water activity and
>low pH, but molds can grow on them rather quickly.

Well molds can exist with slightly lower water activity than bacteria
and so is the fruit curd and fillings which have moderate Aw( water
activity) values which are highly subject to mold and yeast
fermentation ( which incidentally like to live in moderate water
activity).
Bacteria lives and multiplies in higher water activity values ...but
when bacteria weakens or dies due to the lowering of water
activity...the molds,fungi and yeasts takes its place....actively. .

> Normally bakers don't add any preservatives in cake icings nor have
> to use most of the time high processing temperatures..(for example
> in boiled icings) Its common for these tradesmen to make icings at
> room temperatures... In addition to that pH is not an issue with cake
> frosting materials either


>I agree with all these clarifications, but the simple rule of just being
>concerned with water activity is misleading.

It only means one thing. IMO... I am sorry to say that you don't have
a deep understanding with water activity.,and its importance in food
processing.
..Anyway .Its not surprising as its pretty common with many highly
qualified chefs...and most of them scoffed at them including some
cookery school instructors <grin>.who don't follow what they preach
to their cookery students in the culinary school.
....just a few years ago....I met a well known chef who scoffed at
water activity and related terminology and became complacent (in the
his cookery methodologies that pertain to food safety) in his kitchen
Incidentally his HACCP program was found to be faulty. by the food
safety auditor /inspector and was never modified after continuous
warning... from other inspectors who visited his kitchen in the past.
....He scornfully told the inspector...
I had been running this restaurant for more than three decades and
still I never did have any serious food related incident that led my
restaurants closure...
Further
He sneered at them and said.....Stick your water activity (and
stringent food safety rules ) into your arse !
A few months later his kitchen and restaurant were shut down due to
a large number of people who were hospitalized from salmonella
poisoning...from contaminated food eaten during a banquet in his
restaurant......

I had seen a number of restaurant in many places that succumb to this
kind of complacency with disastrous results to their restaurants, and
their reputation.

>Filled breads and pastries use other foods that can support both spoilage and pathogenic >bacteria and molds. I'm saying that we should be careful with all of them.

Breads in themselves have high water activity..in the vicinity of
0.90's .so it can still be attacked by bacteria such as the bacillus
subtilis/mesentericus which causes rope and that is already considered
as spoilage....
Fillings in bread are sensitive to spoilage, it can be meat and dairy
based ; and both have moderate to high water activity as the low to
moderate amount of sugar but low salt and the usual absence of
humectants( which binds water) does not decrease water activity much
and therefore don't prevent osmophilic bacteria ,molds and yeast
from attacking it causing it to spoil....Once fermentation sets in the
water activity values can increase due to the breakdown of food
structure increasing the water content of the spoiled food leading to
other microbes ( including pathogen to attack it)..This chain reaction
can led to a food hazards in many cases and people that are highly
sensitive can be the first to fall ill.
Even this so called jam fillings which can have water activity values
IIRC of 0.60-0.70 is still not immune to these hardy organism....And
certain people that are allergic to certain mold toxins are the first
to succumb to it.
Even your pickles with higher water activity can still be attacked by
halophilic ( salt loving ) bacteria ....However as of now I have not
heard of any body that is allergic to these salt loving bacteria ( or I
may not be aware of it happening elsewhere ) .The fermentation by
products can make food unpalatable....and a spoiled pickle can then
taste awful...
Many kitchen personnels may find these water activityAw, equilibrium
relative humidity (ERH ) terminology as too academic ..and useless in
practical situation but they are wrong!
...

I had been in the food processing industry for decades and although in
baking,patisserie and confectionery are my field....I still exercise
care when preparing food for institutions and have to remind myself
often....water activity is ubiquitous in the food industry

Sorry Bob ...we may differ in our opinions regarding the relevance of
water activity in the general food processing...