Stop Trying to Ripen the Avocado and Let Time Do the Trick.
Look, I’m obviously a big fan of labels, but if there’s one thing that we, as a society, need to give up, it’s the accelerated ripening of avocados. It’s not just my opinion, man; Cook’s Illustrated feels the same way.
Hard, unripe avocados are very annoying, and it’s natural to want to get them to an edible place as quickly as possible, but time is your best tool in this case. You may have noticed a few “tricks” about how to do this by swimming, the most popular of which is to put it in the oven for a while. To see if you can make an avocado worthy of toast, Cook’s Illustrated tested this tip by placing a few unripe fruits in a 200-degree oven.
Result? Slightly softer but slimy avocado. While heating does help stimulate the production of ethylene gas, which CI says “triggers enzymes in the fruit that convert starches into sugars and soften cell walls,” you end up cooking the fruit before it ripens:
Although heat stimulates the production of ethylene gas, there is a limit to both the rate at which it forms and the maturation reactions it induces — you can only speed up the process as much as possible. Placing the avocado in a 200-degree oven doesn’t actually produce more ethylene or cause the fruit to ripen – it just cooks it, so our avocado is slimy and not softened like a truly ripe fruit.
So skip the oven and let these things ripen on the counter, or maybe toss them in a paper banana bag (which gives off a lot of ethylene). It will take a few days, but at least your avocado will be soft and flowing rather than warm and slimy.
Oven-ripe avocados? | Illustrated chef