Most pits/seeds have small amounts of cyanide in them - not a problem tho since an acid environment will eliminate the toxic effects.
Are you sure beer is acidic enough Susan? I remember that strong acids will react with nitriles, but o-chem was a while ago . . .
Hi Tom, You got me thinking - so perhaps my reasoning is a little wrong - is this myth or not? I couldn't find the exact reaction of how the cyanide in the pits of stone fruits reacted in the stomach or in beer (alcohol) but here is what I did find: - The short of this is that the cyanohydrin - mandelonitrile - found in the pits of cherries, apples, etc is very nonreactive and would not be a problem - the cyanohydrin - glycolonitrile - a glycoside, C20H27NO11, commonly found in seeds and other plant parts of many members of the rose family, such as kernels of the apricot, peach, and bitter almond, which breaks down into hydrocyanic acid, benzaldehyde, and glucose can be very toxic under certain circumstances. This glycoside is also found in low levels in cherry pit and so if concentrated could be a problem in some circumstances - but would require quite a bit of concentration - I am still looking for how these would react with an Alcohol - I suspect that the -OH would bind with the H+ and thus eliminate any cyanide gas formation which would be what causes toxic effects - but have not found this in easy research yet.
Thus, my opinion would be that leaving the cherry pits in is safe and that you would probably end up falling down drunk and not being able to consume any more long before any toxic effects from the cyanide in the pits would take effect. There is also some discussion on both of these cyanohydrins having some use against cancer but nothing has been proven (or really disproven) on this.
From Wikipedia - for background info.In humans, cyanohydrins are important metabolites in cyanide detoxification processes.
Some cyanohydrins are: mandelonitrile and glycolonitrile.Mandelonitrile have a structural formula of C6H5CH(OH)CN and occur in pits of some fruits.
Mandelonitrile is broken down into cyanide and benzaldehyde by the enzyme mandelonitrile lyase.
A cyanide is any chemical compound that contains the cyano group (C≡N), which consists of a carbon atom triple-bonded to a nitrogen atom.  Inorganic cyanides are generally salts of the anion CN−. Of the many kinds of cyanide compounds, some are gases; others are solids or liquids. Those that can release the cyanide ion CN− are highly toxic.
In IUPAC nomenclature, organic compounds that have a –C≡N functional group are called nitriles. Nitriles, on the contrary, are never inorganic compounds.   An example of a nitrile is CH3CN, acetonitrile, also known as methyl cyanide. Nitriles usually do not release cyanide ions.
A functional group with a hydroxyl and cyanide bonded to the same carbon is called cyanohydrin, and cyanohydridins are hydrolyzed into hydrogen cyanide and a carbonyl compound (ketone or aldehyde).
Many cyanide-containing compounds are highly toxic, but some are not. Nitriles (which do not release cyanide ions) and hexacyanoferrates (ferrocyanide and ferricyanide, where the cyanide is already tightly bound to an iron ion) have low toxicities,
while most other cyanides are deadly poisonous.