Expiration date is a hot topic in the production of chocolate sweets. How long can candy be stored? How topreserve the taste, shape, texture, proper microbiology and slow down a plenty of chemical processes thatreduce the quality of sweets during storage are the main problems that will always face the chocolatier.
Why?
Mistakes are costly. Finding good flavor combinations, market research, target audience research,advertising campaigns — all this will be a waste of time if your loyal customer finds a fungus after bitinga truffle. And there can be many reasons for its sudden appearance.
The expiration dates of candies depend not only on the certain ingredients ratio in the recipe, but also onthe manufacturing technology, compliance with sanitary and hygienic standards and rules in the workshop,regardless of the scale of your production, whether it is a large factory or home cooking.
The bad news is that we do not give clear formulas that will help you accurately calculate the shelf lifefor any recipe in this material — such formulas simply do not exist. The good news is that some things canbe measured and planned. Therefore, today we will talk about what data helps to predict expiration dates,what factors lead to sweets spoilage and how you can reduce or completely avoid their influence.
What can happen to sweets during storage?
Let's start horror stories with microbiological spoilage — the most basic and most dangerous factor for thehuman body, which can be accompanied by the formation of toxins and the development of pathogenic bacteria.Favorable conditions for the development of bacteria, fungus and yeast are water, air, a comfortabletemperature and a source of nutrition. In our case — the candy itself.
White plaque is fungus. Ugh…
The most obvious sign that the candy has gone bad is mildew. Many mistakenly believe that if the truffle isnot covered with mold, then you should not worry, and everything is good with it. And there are even moredesperate optimists who simply cut off a piece covered with fungus and think that from now on the product issafe. Unfortunately, such optimism can lead to poisoning, since the mold lives not only on the surface, butalso penetrates into the product.
Violation of microbiology is not always accompanied by signs visible to the eye. In addition tomicrobiological spoilage, there are a number of other degradation processes that are invisible. For example,chemical processes are different types of oxidation more associated with fats. Outwardly, such damage, as arule, doesn’t show itself in any way, but you can feel a rancid or simply unpleasant aftertaste that is notcharacteristic of the product. Surely there are not so many of you who are ready to give a second chance tonut butter or a rancid nut-flavored chocolate bar. You won’t go to the FDA with a complaint, but obviouslyyou won’t buy the products from such a manufacturer anymore.
Spoilage can also occur as a result of a number of physical influences: mechanical damage, deformation orloss of integrity. Sounds harmless compared to the types of spoilage described above, but it’s important tonote that physical processes can lead to chemical or microbiological processes easily and without warning.
The result of the fat bloom of chocolate.
BTW deformation is not always the result of mechanical damage — the candy can also be deformed as a resultof drying out. Wet fillings tend to dry out, due to which its consistency begins to change, grains of sugarappear, it loses its silkiness, becomes rough and the candy changes appearance itself. In this case, voidsappear between the filling and the layer of chocolate, which create excellent conditions for the growth ofmicroorganisms — the «elements» mentioned above: air, temperature and water. The influence of air can bereduced by glazing the filling in chocolate, which will serve as a protective layer for it (which is whyit’s important that the layer is intact, without cracks and holes). At the same time, the filling itselfshould also be inside without air bubbles, which can form when whipping ganache with a blender. This can beavoided by keeping the blender immersed in the mass while whipping. Of course, the most reliable protectionagainst air is a vacuum, but let's face it: few people will vacuum candy after opening the package, so it'sbetter to proceed from reality and protect the product in other ways. The temperature is even easier — itneeds to be lowered, ideally, by storing sweets in the refrigerator so as not to allow microorganisms tofeel good and grow quickly. But what about the last «element»? Let's figure out...
How to extend the shelf life of sweets containing water?
Yep, unfortunately, the presence of water in the filling composition is the main factor that significantlyreduces the shelf life of the candy. Therefore, emulsion fillings spoil the fastest, that is, our dearlybeloved ganache on cream, fruit puree, juice or just water. And the more water, the shorter the shelf life.
Factory-made sweets can lie on the store shelves without any special temperature regimes for a long time —from 6 months to 1 year, and some types in general up to three years. What’s the secret? The fact that themain ingredients of factory sweets are sugar and fat. This composition ensures that there are no problemswith microbiology, since there is no water in the composition, and with the right ratio of ingredients andthe addition of antioxidants, chemical processes can be slowed down as much as possible.
The composition of factory sweets is not so good.
But don’t rush to «pump out» the water from the composition of your sweets! Water provides such a delicate,smooth, melting consistency of the filling, which cannot be created from sugars and fats. By reducing theamount of water and increasing the content of sugar and fat in the composition, we certainly increase theshelf life, but as a result, the craft product loses its attractiveness, which appears in a special texture,balance of taste and aroma, moderate sugar content and approaches mass- market.
As part of the filling, we are not worried about all the water, but only the so-called «free», which is notassociated with other substances. From here, pardon the pun, the concept of «water activity» flows, denotedby the abbreviation aW (water activity). The more free, unbound water, the more opportunities for thedevelopment of various kinds of bacteria, yeast and mold, which means that the shelf life of the fillingbecomes shorter.
Water activity is measurable. There are special devices — water analyzers (aW-meters). They allow you tocalculate the free water in the filling. Expressed as aW in numbers ranging from 0 to 1, where water wouldhave an activity value of 1 and the driest product would tend to a value of 0. To calculate the active waterin the fillings you can use a special program Pro-Choc or Ganache Solution diagrams.
Why do you need to know all these numbers? In order to predict the shelf life of the candy. So, for example,a candy with aW 0.7-0.75 is more likely to retain all its properties for 60 days under certain conditions:storage temperature 10-13ºC, relative humidity about 70-75%, in a tightly closed package away from heatsources, light and strong odors.
There is another important water nuance that concerns the storage of sweets: active water is closely relatedto the concept of equilibrium moisture content. This means that the filling will give or take moisture untilits aW-level is in equilibrium with the environment. In a room that is too humid, the filling will begin toabsorb moisture, which will lead to the formation of free water, which will disrupt the stability of thefilling and serve as a favorable base for the growth of microorganisms. In a room that is too dry, thefilling will give off moisture and dry out, and its consistency will become rough due to sugarcrystallization, as we wrote earlier. Sugar dissolved in water tends to crystallize back. Surely, many ofyou have come across this during the preparation of syrup: after complete dissolution in water, at somepoint, sugar begins to actively collect into crystals, which by no means want to dissolve. This is due tothe fact that during boiling, the moisture evaporates so much that it isn’t enough to keep the sugar inmixture-form. To avoid reverse crystallization, glucose syrup, which has anti-crystallization properties, isadded to fillings, syrups and other substances where there are sugars. If the room has a relative humiditylevel of 65-70%, then the filling with aW of about 0.7 will be stored as well as possible, since themoisture inside and outside is in balance, drying and sugaring, or vice versa, an increase in humidity willnot occur.
A logical question arises: how to reduce water activity? To bind and neutralize so that it doesn’t become acondition for the development of microorganisms. To do this, various types of sugars are added to theemulsion fillings, which have hygroscopicity, the ability to retain moisture, prevent crystallization andother properties.
Let's get to know them better.
