Hey everyone... Im not sure where else to post this so I figured this should be a safe spot.

I have a very simple buttercream recipe that involves confectioners sugar, butter, shortening and a little bit of raw (pasteurized) egg.

100% conf sugar
67% butter
33% shortening
1 or 2 eggs (depending)

My question is on the safety of leaving this at room temperature on a cake. Im under the assumption that sugar can be a preservative, but I have not found any information on the ratio of sugar with regards to the other ingredients that can keep the frosting safe.

Can someone fill me in on some additional information? Thanks in advance!

I honestly am not quite maybe you could use a egg substitute? I stick to BC with no eggs

Food safety says to err on the side of caution. You get a maximum of two hours above 40 degrees for that frosting. That includes decorating, transportation and display. Not much of a window. You might want to look for substitutes like meringue powder.

Ok, for the sake of argument... lets say I remove the eggs. Does that change things at all?

Without the eggs it could sit out for a week or more.

So it appears that the butter is fine, just the eggs is the problem in this recipe?

Is there a substitute for eggs that would help with the richness/creaminess of this frosting without the need for refrigeration on a cake?

Thanks for all the info everyone!

are you using pasteurized shell eggs or egg whites from a carton?

I was using an egg that I pasteurized myself (put it in a pot of water kept above 145 deg for 5 to 7 minutes).

Well, to me it doesn't sound much different from IMBC or SMBC, as far as egg safety.

I don't really see much of a difference. Maybe the fact that you pasteurize it yourself, I would maybe use a cartoned egg white. I think pastuerizing eggs at home is shunned....though most cartoned eggs are now considered pasteurized already.

I leave out IMBC with pastuerized egg whites for one or two days. Most decorators that use it....Duff, Margaret Braun, etc...HAVE to leave it out.

Granted, most people that make the kind of buttercream you are talking about use meringue powder or powdered egg whites.

I'm no expert, but if you are talking about truly pasteurized eggs I don't see what the problem leaving it out one or two days would be?

This is where I need to find some science behind it... the only thing I seem to find is opinions one way or the other...

Where is Shirley Corriher's book when I need it...

Someone one here....Mike or Doug (I think it was a man)
talked once about the water content/vs sugar content and that is what makes the difference when it comes to spoilage.



Maybe one will see this and clarify.

If you leave out the eggs and use a meringue powder you should be just fine, if you loose the eggs and butter and go to a shortening based BC you could leave that out for a ridiculous amount of time. It also has the advantage of not softening at a low temp so you don't have to worry about the icing sliding off the cake at room temp even if it gets somewhat warm

I've honestly never seen eggs used in a confectioner's sugar+shortening buttercream...........

I use ultra-pastureized heavy whipping cream in my BC (about 36% fat), and it holds up for days unrefrigerated. It's very creamy and I've had people mistake it for an egg based meringue buttercream.

Rae

hmmm... what does the heavy cream do? Would it help to accomplish the same end result as the egg yolk? I don't have any on hand to try but sounds like an interesting substitution.

Hey - Man here - and it is a bizarre relationship that these frosting have with microbes. Microbes want water to live in and a little sugar to eat. A lot of sugar screws things up for the microbes and literally pulls water out of the critters causing them to die.

Keep moisture away so that the critters don't have a place to start. The more sugar the better, for preservation purposes. the egg relationship is the whole salmonella thing which is highly exaggerated.

However, I'm no microbiologist and can't give you exact advice. There was another website out there that hired a microbiologist to actually test specific recipes. The results were very much in our favor. However, I can't find the site. It wasn't 911. Any help out there? It was good info...

Most American b/c's are shelf stable, even when milk or cream are used as the liquid.

Sugar is hygroscopic, or moisture absorbing.
The powdered sugar in American b/c's controls the water activity in the butter/margarine and/or milk or cream in the mixture. (Butter and margarine are both 80% fat and 20% water, while shortening is 100% fat.)

Water activity & microbial growth:
(Prolonging Bakery Product Life.)

http://tinyurl.com/6fbkcz

WJ Scott in 1953 first established that it was water activity, not water content that correlated with bacterial growth:

http://tinyurl.com/bmsato

Formulating for increased shelf life:
(Decreasing water activity results in hostile environment for bacteria.)

http://tinyurl.com/csu2b9

HTH

P.S. Just like BlakesCakes, I use heavy whipping or at least half-half in my b/c recipes to add richness.