Clean wood ash (SM1)

Hi neighbors,
Since it's the right season I wanted to check if anyone happened to have some clean wood ash (so burned using only wood, maybe a bit of other natural materials like some straw, paper, etc but no lighter fluid, petrol, plastics or other pollutants) going spare after a bonfire? I'm looking to grow some mushrooms in the garden, and they're a type that is best kickstarted in a firepit or similar environment with ash present. Would be looking for around 2 buckets' worth, ideally cool enough to transport in bags or plastic buckets.
Thanks in advance!