Suppose that you have some avocados, and that the avocados are under-ripe and hard.
Suppose that we leave the peel on, so that the green flesh of the avocado does not oxidize and turn brown.
Can you soften hard avocados by freezing them, and then de-frosting them afterwards?
Most vegetables turn mushy after they freeze and thaw back out again.
Is freezing and thawing a viable way to make soft avocado for making guacamole?
Yes, you can soften hard avocados by freezing/defrosting, but it won't ripen them and make them taste good. Avocado's have a high water content, and like many fruits/vegetables with a high water content this water will crystallize as it freezes, breaking cell walls, and resulting in something more mushy/spongy when thawed. If you're not interested in ripe avocado, just soft: A blender is also an option that's even faster than freezing/thawing, and will directly result in something green resembling unripe avocado guacamole.
Again: freezing won't ripen an avocado, so it'll taste different (I'd say bad but tastes differ). There's a difference between 'ripe' and 'soft'. The only reliable 'faster ripening' trick for avocados I know of is putting it together with other fruits that release ethylene gas (like bananas, apples, or mangoes), the kinds of fruits you're not supposed to store together unless you want them to get ripe fast. If you want to speed it up a little, you can use a paper bag and perhaps a slightly warmer spot (e.g. if your kitchen doesn't have heating and the living room does, a fruit bowl on the living room table).
