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Post by blondce on Dec 29, 2006 13:56:56 GMT -5
I have been making truffles for about 10 years and have had a new problem. Some of my truffles (not all batches) develop a thin layer of mold between the ganache and the shell. The truffles are only about a month old!
I had this happen once when I messed with the recipe and added gelatin to the ganache to try to get a firmer center.
I am using a simple ganche recipe of Cream and Chocolate. Some truffle have liquor for flavoring and they seem to not be as likely to get moldy as the ones without liquor.
Could I be doing something wrong when I scald the milk? Too hot? Not hot enough? I have always stored my chocolate at room temperature, which I thought I could.
Any help would be greatly appreciated! People are starting to get leery of my chocolates!
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Post by chocdoc on Dec 29, 2006 16:15:32 GMT -5
Can you give us the proportions of ingredients you used to help us figure this out?
It's all about available water. If you have simply chocolate and cream you have a lot of water available to molds and bacteria to help with their growth. If you replace some of the cream with butter (which is less % water) you decrease the available water. You can decrease AW by adding some glucose, some invert sugar or alcohol.
The liquor is helping prevent the mold by decreasing the available water. I believe the amount you need to add for best preservation is 17% of liquid, so if you have 1000 grams of cream you should be adding 170 grams of liquor.
The bible for helping figure this out is Jean Pierre Wybauw, Fine Chocolates, Great experience. It's a wonderful book and explains how to improve shelf life.
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Post by blondce on Dec 29, 2006 20:23:31 GMT -5
We use 1 lb dark chocolate 1 cup heavy cream 6 tbls liquor (champagne cognac, grand mariner, etc.)
So when I don't se alchohol (for some friends) I should replace 17% of the cream with butter?
I will look into the book you mentioned.
Susan
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Post by chocdoc on Dec 29, 2006 22:19:52 GMT -5
Not quite sure if the butter would replace quite the same way, but with the alcohol for that recipe you have about 250 grams of cream so 17% is about 42 grams of alcohol, which is around 3 tbsp, so you clearly have enough alcohol.
I don't have my Wybauw here right now, so I can't look up the butter info, but I'd probably start by decreasing my cream to 200 grams and adding about 50 grams of butter.
You said you haven't had problems before (except when you added gelatin). Has anything else changed? New type of chocolate, change in type of cream?
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Post by Brad on Dec 29, 2006 23:20:55 GMT -5
I'm no expert here, but I have taken a lot of advice from experts and the unanimous consensus is as follows:
If you are using perishable items in your chocolates, such as cream and butter, ALWAYS ALWAYS ALWAYS refrigerate them and use them within a couple of weeks, unless you add a preservative.
Alchohol is NOT a preservative. In fact it aids in curdling milk. Think about any time you make a "foo foo" drink with alchohol and cream. The cream ALWAYS curdles eventually.
In fact, the small amount of alchohol used will most likely evaporate as you are mixing the ingredients anyway. It does so VERY quickly.
One successful chocolatier I know, actually makes his truffles and then freezes them until they are ready to be sold. This will allow the truffle to be stored for a couple of months quite easily.
Brad.
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Post by sugaralchemy on Dec 30, 2006 17:05:12 GMT -5
First, when you are working with your filling, do your best to keep things clean and sanitized. If you can have fewer mold spores and microbes in your filling, it can slightly slow their growth. Potassium sorbate would be an extremely effective ingredient to fight mold growth. Use no more than 0.1% (the maximum amount allowed by the FDA) for some decent preservation effects. The pH must be 6.5 or lower for it to work, and lower pH values are better. Don't worry, most truffle fillings made with regular (non-alkalized) chocolate will be fairly low. I believe food grade potassium sorbate can be purchased on eBay often. Sorbate occurs naturally in the form of sorbic acid in the berries of Sorbus aucuparia if I recall properly. I don't see any safety concerns with it. In fact, it is found in many 'health foods' and one particular health food vendor has a small write-up on it targeted at those concerned about safety: www.soybean.com/ps.htmIt won't replace the need for you to test the shelf life and still take precautions - it doesn't mean your chocolates will last forever, simply that they will last longer. Potassium sorbate is more effective at lower pHs. Get a little citric acid in dry form and see if you can't use a little bit more in your fillings, which will lower the pH. Obviously not so much to destroy the flavor, but every bit helps, and you might find some flavors are enhanced by the citric acid. Aside from preservatives and pH, you can lower the water activity ( en.wikipedia.org/wiki/Water_activity ) by: -Using less water (remember, cream is mostly water) -Incorporating invert sugar (sucrose that has been broken down into glucose and fructose - smaller molecular weight = more effective at reducing water activity) -Adding more salt (though the maximum amount you can practically add is very limited in many things, every bit helps and some flavors like peanut butter might take salt well) There's no single way to nail the issue of food preservation, but if you combine a lot of different techniques as appropriate for each formulation, you can really improve the situation. Formulation changes (less water, more salt, acid, sugars), incorporating a preservative, working with clean/cooked ingredients and storing the product frozen/cold can all contribute to good shelf life. Hope this helps.
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Post by chocodisiac on Feb 19, 2007 21:33:26 GMT -5
I'd like to just weigh in here and say that:
1. To me, personally, gelatin in truffles sounds just disgusting!
2. Likewise, potasium sorbate, a preservative, keep that sort of thing for the large-scale mass producers. If you pride yourself on being any sort of artisanal chocolatier, in distinction to the former, use fresh, natural (by which I mean minimally messed with--I realize that moniker is heavily abused) ingredients, and, as Brad said above, refrigerate the product for heaven's sakes (they are/should be made with heavy cream after all), and consume them within 2-3 weeks! Truffles really should be considered a fresh food, and shouldn't be hanging around for a month (unless they are frozen).
Having said that, some of the suggestions above concerning the amounts of liquid /alcohol and sugar could prove interesting. Myself, I use nearly a 1-2 ratio by weight heavy cream to (very dark) chocolate, and a healthy dollop of alcohol or alcohol-based vanilla, as well.
Hope this is helpful!
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Post by chocoaddict on Mar 9, 2007 21:42:28 GMT -5
I'm new to this forum but have been experiencing a similar problem as "blondce" after my supplier stopped carrying a particular brand of heavy cream, and replaced it with a cream higher in fat content. With the new brand, my chocolates now only have a shelf-life of 1 week when before they had a 3 week shelf life. I store them in 55 degrees temp in rather low humidity but the mold still comes. I am so stumbled by this problem. Similar to "blondce" I don't add any additional sugar or butter to the recipe. I don't add gelatin.
I guess my question is why does a change in fat contant of heavy cream change the shelf life and what can I do.
Thank you.
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Post by sugaralchemy on Mar 15, 2007 13:38:09 GMT -5
It's possible the cream is lying and is actually lower in fat content. It's also possible that the cream is not as "clean" microbiologically - meaning it has more mold spores in it, which help accelerate their growth. Or perhaps the cream contains a strain of mold that is particularly adept at growing in that environment. Depending on where you live, there might even be some additives (declared on the label or perhaps not!) in the old cream that were inhibiting mold growth.
I'd also encourage you to consider that something may have changed in your handling of the chocolate. So many nuances affect the process as well - be careful to control them.
If you want to test the microbiological status of things, try heating the cream to about 165° F and holding for about 1 minute. Allow to cool (if necessary) in the same container and avoid as much cross-contaimination as possible, using in your truffles immediately.
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