Well maybe they aren't beers but this book should get you going if you were marooned. It has recipes for wines and meads made form all sorts of things. Unless you're unlucky your island should have some fruit on it. I've always wanted to make birch sap beer.
[url:iy6dszqu]http://www.amazon.com/gp/product/1580171826/ref=cm_cr_pr_product_top[/url:iy6dszqu]
This book has loads about how tribal people made beer with minimal santitation which might be useful on an island. It's got a chapter called Psychotropic and highly inebriating beers which may help when stuck on the island.
[url:iy6dszqu]http://www.amazon.com/Sacred-Herbal-Healing-Beers-Fermentation/dp/0937381667/ref=pd_sim_b_2_img[/url:iy6dszqu]
Warning this book is Very hippy so avoid if you've an aversion to that sort of thing <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt="

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