hey Maria, if you have some kind of dirt-floored or concrete-floored storage shed you can try that. Also maybe try getting cheap tarps from the dollar store, the kind that are blue on one side and silver on the other. Put it over the storage container silver side up to help deflect heat/any sunlight. Any shady area not too close to the house in particular as houses give off heat.
Usually it's easy to tell if sap has gone off. It'll often go cloudy and smell off. But sometimes it stays deceptively clear and smells ok. Best thing is to take a small saucepan of the sap, bring it to the boil. If it smells like you're boiling frogs, or just like swamp water on a late summer day, ditch it. Unless you want to make a novelty batch of swamp water-flavoured maple syrup lol :-) Good luck!
Been tapping since 2008.
2018 - 17 taps/7 trees...819l sap, approx 28l syrup
2019 - 18 taps/8 trees...585l sap, 28l syrup...21:1 ratio
2020 - 18 taps/8 trees...890.04l sap...gave away about 170l, 30l snafu'd....23l total for me from approx 690l
2021 - 18 taps/8 trees...395l sap, 12 l syrup
2022 - 18 taps/8 trees....7 sugars 1 red due to #2 having surgery so had the season off....582l sap, 18.5l syrup
2023 - 18 taps/8 trees...all sugars again. 807l sap, so far approx 14l syrup