Since I began looking into ways of being frugal in west London I've spent time with survival experts, made fires without matches or lighters, scoured the blackberry hedges for fruit and caught fish for dinner.

However, trying to extract a tasty beverage from the humble acorn was to prove my greatest challenge yet.

Free food is a relative phrase. If you suffer for your grub, you're paying out in pain and even lost friendships.

In Richmond and Bushy parks, productive oak trees were surprisingly few and far between.

Eventually, I found four oak trees beside Hampton open air pool and within half an hour I had a couple of kilos of the nuts. Of course, I used a sledgehammer to crack them.

It is believed the Arapaho Indians actually peeled their nuts before crushing them, a task which would take them many days. Unfortunately, time wasn''t on my side, and so I wrapped the nuts in a cloth, to avoid losing anything, before bashing them with the sledgehammer.

Once smashed, I picked the bits of shell out.

It is also thought the Indians then made a kind of sieve out of a mound of sand scooped out at the top, put the crushed nuts in, and poured water on them.

"This would be to leach the heavy tanin out of the nuts," said survival expert Enrich Cucarella, who I met last month for my feature on the Crane Valley.

Again, impatience got the better of me, and although I ran some water through my crushed acorns, it was probably not long enough.

The next stage is to take your crushed nuts and bake them on a tray, in a medium oven, for 15 minutes. Some nuts caught light, but the rest had what I thought was a rich aroma.

This is how they made a kind of fake coffee in the last war, so I felt confident something good would happen when I poured out the brew for my colleagues after adding boiling water.

However, nothing prepared me for the reaction from my Informer colleagues, one of whom said she would rather eat gravel than drink any more of this 'disgusting' liquid.

For me, it was a good wake-up drink. I agree there was the sourness of tanin as an aftertaste, but millions of squirrels can't be wrong.

Helen Clarke's tasting notes:
"I don't know how to spell this, but 'MURRRGH-AARH'. I don't want to be too unkind though. It did become a lot smoother in taste after a while. I admire the ingenuity of making it, but I won't be queuing up for more."

Patsy Duffy's tasting notes:
"No matter how hard times may get, I will never, ever, resort to drinking coffee brewed out of acorns. It was sharp and bitter with not a hint of coffee taste."