Ah, yes, bottled apple cider. A delicious fall favorite for many, especially in the United Kingdom! Cider has been produced in the UK for several hundred years and, while the process has changed, it’s still essentially the same.
So what does apple cider have to do with cleanrooms and particle counting?
Well, clean rooms play an important role in food processing and manufacturing! We want to know that what we eat and drink is produced in clean spaces that prevent particles from contaminating the process. There is also a science element to bottling food that we often forget about.
So how exactly is bottled apple cider made?
First things first, you have to prepare the apples! With over 300 apple varieties commonly used for ciders to choose from, it is quite a task to pick which apples you want to use. You should consider the sugar, acid, and tannins when choosing your apples to be used for ciders. More sugar will mean a sweeter cider, while more acid will make the cider tarter. The tannins can make the cider drier. So once you decide on your cider profile, choose suitable apples!
You’ll then have to receive the apples and sort them. You will want ripe apples that haven’t turned yet. If they’re spoiled, throw them out. At the same time, if they are not ripe yet, they can make the cider taste stale.
Then you’ll want to wash them well. In an industrial setting, generally, a pressure washer is used before you start crushing them.
To get the most out of juicing your apples, core them, then cube them before crushing. From there, you can work the juice out. In industrial settings, manufacturers will use a fruit press on the pulp that has been milled. But at home, you can use a muslin sack or jelly bag.
While this might seem like a simple process for home-brewed apple cider, manufacturers want to make sure everything is perfect, safe, and matching. So after they get the juice from the apples, they take it into a cleanroom to analyze it.
Why use a cleanroom? They want to make sure they are getting an honest reading of the juice without any contamination. The cleanroom is not only used to evaluate the juice but also to clean the equipment used on the juice.
When evaluating the juice, they typically measure pH, titratable acidity, sulfites, and sugar (which will determine how alcoholic it is). Each of these can be adjusted through various measures if they are off and affect different parts of the end product. It might be taste, bitterness, alcohol level, or safety.
Manufacturers allow the juice to settle for 24 hours after adjusting it and then siphon it into a new container, leaving behind pulp and debris. Now it’s time for fermentation!
At this point, you have apple juice. While a delicious treat, we are going for something a little different. So it’s time to ferment! The juice should be stored at 72°F in clean containers topped with cotton (pressure builds during fermentation, which can cause a jar with a regular lid to explode). If you keep it at a lower temperature, the final product might be more fruity and flavorful, but it will take longer.
In a few days, you will see fermentation bubbles rising and sediment settling at the bottom. If you prefer a sweet and mild cider, now is the time to start “racking off” the cider. This process involves removing the clear liquid from the sediment.
If making cider at home, put a 3 foot long, clean straw or plastic tube into the clear liquid and suck on it like a straw until you just taste the juice. Pinch off the straw and put the end into a clean jar.
But if you really want to ferment the cider to get the bite of hard cider and higher alcohol content, leave the juice fermenting for around ten days. Instead of using cotton, use several layers of muslin or an airlock on the bottles containing the juice. This will produce a dry, hard cider.
In a commercial setting - and sometimes at home - yeast is often used to speed the process along or create a higher alcohol content, amongst other aspects. For those who use yeast, they also have to add other nutrients to manage the yeast response.
Once fermented, it needs to rest and mature for 2-6 months. It should be kept just above freezing to no higher than 60°F. This process enhances flavor, but you need to watch for oxidization. Cider can be more susceptible to oxidization than wine.
Once matured, this is considered base cider. To really intensify the flavors and finish the process, manufacturers will often barrel the wine for another three months. They might also carbonate (although this can be done after bottling, too). They will use this time to sweeten and filter the cider, as well.
Next, you want to pasteurize the cider. This kills the germs that could cause illness, like E. Coli or Salmonella. To pasteurize the apple cider, manufacturers heat the liquid to at least 160°F but not higher than 185°F to avoid the taste of being cooked.
Once pasteurized, transfer the cider into clean jars and refrigerate immediately. If you’re making your own and want it to last longer, you can freeze it. If you freeze the cider, let it cool completely in the refrigerator before putting it in a glass jar with some space left at the top for it to expand.
Similar to bottled water, apple cider is often bottled in a cleanroom to prevent contamination. To further prevent contamination, many manufacturers pasteurize in the bottle. This kills any germs that might have found their way into the cider or the bottle!
While we might want to make this tasty treat at home (and we can!), manufacturers have to follow a different set of regulations and guidelines to keep us safe. This involves using a cleanroom at fundamental parts of the process to make sure there is no contamination.
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