How to Make Proper Preserves the Tessa Kiros Way
I have spent years making small batches of jam at home, and honestly, most of what you find online is overcomplicated nonsense. Tessa Kiros has a very specific approach to preserves that cuts right through the usual advice about pectin tests and fancy jars. It is simpler than you might think and it relies on quality fruit rather than additives. Her method centres on using ripe but firm fruit and letting the natural sugars and acidity do the work. The key insight that most beginners miss is that the type of sugar matters enormously. White granulated sugar gives a clean bright flavour and sets reliably because it is pure sucrose. Brown sugars or unrefined options introduce moisture and impurities that throw off the gel point. If you are making something like quince or medlar, which Kiros frequently works with, she recommends a heavier hand with sugar and a longer, slower boil to break down the tannins naturally present in those fruits. Here is the practical process. Start with fruit that is just past peak ripeness — slightly soft but not mushy. Hull and prepare it, then layer it in a preserving pan with roughly 400 grams of sugar per kilogram of fruit. Let it sit for an hour or two until the sugar draws out all that juice. That waiting period is non-negotiable if you want even cooking without burning the bottom. Once the sugar has dissolved into the liquid, bring it to a rolling boil over medium heat. Do not stir excessively once it reaches the boil or you risk crystallisation. A gentle agitation every now and then is enough.
The set test is straightforward. Drop a small spoonful onto a cold plate that you have kept in the freezer for ten minutes. Push it with your finger. If it wrinkles cleanly, you are done. If it runs, keep boiling and test again in three to four minutes. This usually takes between twelve and twenty minutes total depending on the fruit and your pan size. I once tried to rush a batch of fig jam by cranking the heat too high and ended up with a thick syrup that never gelled properly because the high temperature scorched the sugars before the pectin had a chance to activate. The workaround was starting the batch over with fresh fruit and a wider pan that allowed faster evaporation without charring. Pack the hot jam straight into sterilised jars while it is still bubbling. Wipe the rims quickly with a damp cloth to remove any stickiness that would prevent a proper seal. Turn the jars upside down for thirty seconds to create a vacuum, then return them upright. This old-school technique works reliably for jams and preserves that will keep for a year or more without refrigeration. Kiros tends to favour smaller jars because the contents get used quickly and the flavour stays brighter when the seal is fresh. One counter-intuitive detail worth noting: adding a splash of acid like lemon juice is not always necessary. Fruits such as strawberries and raspberries have plenty of natural acid for setting. Over-acidifying can actually prevent the pectin network from forming correctly and leave you with runny jam. Only add lemon juice if you are working with low-acid fruits like peaches or certain varieties of plum.
The whole process from start to finish, including prep and packing, typically takes about forty-five minutes for a two-kilogram batch. The result should be glossy and spreadable with a flavour that tastes distinctly of the fruit itself rather than just sweet jam. That is the whole point of doing it this way.
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