2/ Skim the oil as often as you can
Whenever you use your fryer, the food you cook in it will leave bits behind: bits of batter, breadcrumbs or even chips can get left in the fryer.
If you can (and I know how hectic lunch or dinner service can be) try and skim the oil of any debris immediately. The key is not to let the debris sink to the bottom of the fryer, next to the elements or burners in a gas fryer. This is because this debris will then sit there and slowly darken and, in the case of bread or potato based products, caramelise as the starch they contain breaks down into sugars.
These items do two things: 1/ they change the taste of the oil and, 2/ they make it less efficient at heating and cooking, as they soak up heat energy meant for heating the oil.
This can make a drastic difference to cooking times. Chips that would have taken 4 minutes are taking 6, fish that would have cooked in 3 taking four and a half. This means that you will be producing food more slowly and that will hit your bottom line and your customer satisfaction.
3/ Take time to keep the fryer clean with a quick spruce up
Before you change your oil, I’d advise taking a break between sessions to drain your oil and clean out your fryer with paper towel. This will allow you to clear the debris from the bottom of the machine and freshen up your oil by sieving it.
Although this won’t save really old oil, it will help to keep two-or three day-old oil fresher and reduce the influence of taste build up within the oil itself
4/ Have a regular schedule to change your oil
Whatever you are doing in between oil changes, if you have a busy business I’d recommend changing your oil every five days at least. That, for me, is good housekeeping and will ensure you have oil in the best possible condition.
But don’t take that as gospel – you have to judge when your oil needs changing by its colour – the darker the worse its state. I’d recommend changing it when you start to see a dark tinge to the oil, rather like a weak cup of tea. You should always be able to clearly see the bottom of the fryer.