We usually stock on sugar and salt when there is a promo especially if the discount is huge. However, we live in a tropical country where humidity can ruin the quality of sugar and salt that’s why it is advised not to stock on it. When the salt grains become sticky, it is irritating when you cannot extract salt from the shaker. At least with the sugar, you can use a spoon even if the sugar becomes sticky. But the best is not to stock a huge volume of sugar and salt.
I think it depends on the temperature of the room that you store it. I noticed that our kitchen is not directly hit by sunlight, unlike my dad's bedroom, so the items in the kitchen isn't as vulnerable as compared to the items in the bedroom. For example, my brother's charger that was placed in the tray for a long time since it wasn't being used got smeared and had that "melting" feel to the rubber wire because of the intense heat. So luckily, our kitchen is safe and you can store food and condiments safely there.
I always store my sugar and salt in the fridge and it lasts quite long. I also live in a humid area and I think the refrigerator keeps the humidity out. I always stock up on sugar and salt and I just did today. They usually sell one kilogram of sugar for 3 dollars and today, it was only a dollar. I purchased 10 kilograms and I stores it in my fridge. You need a larger fridge, though.
Fridge is a good place to store even spices provided they are kept in air tight containers. I stock sugar and salt as well because here in a mart we get free 1 kg sugar packets over a certain amount of purchase limit. I stock them in pantry and even during the hottest summer or humidity it hasn't gone sticky.
I come from another premise altogether. I rarely use sugar and also planning to limit my salt intake due to health reasons. In any case, I would explore another alternative which is a natural form of sugar derived from a plant called stevia which can be easily grown in gardens in the tropics where I come from. Its cheap and can be safely used by diabetics besides being many times sweeter than ordinary sugar.
I also store my sugar and salt in the fridge to prevent it from getting sticky as for the sugar it is also great since ants dont get in them. I also live in a humid place where I feel most things get ruined but we must always find ways around those problems.
When we are buying salt and sugar, we also buy in large quantity. However, in my experience and observation if we have stock of any thing, we will be consuming more. Let me exemplify. You have one kg sugar in your home, if you want to make sherbet, you may postpone because you don't have enough stock. However, if you have enough stock you will make sherbet. You will be consuming more.
I am from the sugar area where it is available round the year so we do not have to stock it in larger quantities. I buy 5 kg at a time which is enough for 2-3 months for two of us. Besides the rates of sugar is less than 50-60 cents throughout the year which makes it needless to stock it. We are one of the major producers of salt which is available @25 cents or less packed by best companies in the business and available at every grocery store.
