Charge

Conservative is the upper literature value. It raises the flavour estimate and the cyanide together, because they come from the same molecule.
grams
kernels

Route

How much of the amygdalin the kernel's own enzyme converts during the 40–50 °C hold in water. The rest arrives intact and Brett finishes it in the bottle. Med-Low, unverified.
Benzaldehyde surviving in the beer after a Stage D addition, 0.8–1.0 (Med).

Batch and drinker

litres
mL
kg
per single sitting
mg/L benzaldehyde above which it reads as almond essence rather than marzipan.
 
 
 
What you gain
–
 
What it costs
–
 

Marzipan intensity in the finished beer

0.5 mg/L
threshold
2 mg/L
clear marzipan
ceiling
nothing gained detectable the band worth aiming at almond essence, cloying
Log scale, 0.1 to 20 mg/L benzaldehyde in the beer. Benzaldehyde is what marzipan smells of, and it is the co-product of the cyanide release, so this is the whole of the flavour you are buying with the charge below.
Marzipan per gram of kernel
–
mg/L per g
Bottles to one reference dose
–
in one sitting
Cyanide cost of flavour
–
mg HCN/L per mg/L benzaldehyde
One bottle
–
% of reference dose
Two bottles, one sitting
–
% of reference dose
Deferred to the bottle
–
% of the cyanide, unvented

Routes compared, same charge

Route Marzipan gained CN / bottle % ARfD Cost What it does

Backwards: the charge that fits

Charge for clear marzipan (2 mg/L)
–
g
Charge at the flavour ceiling
–
g
Charge at 50 % of one ARfD
–
g · the primer's warn line
Charge at one bottle = one ARfD
–
g

Cyanide: where one bottle lands

Reference dose
No-effect dose
0.105 mg/kg
Lowest fatal
0.56 mg/kg
Mean fatal
1.52 mg/kg
Log scale, mg cyanide per kg body weight from one bottle at one sitting, as on the calculator above.

A calculation aid for food-safety self-assessment, not a clinical or regulatory determination. Kernel content varies severalfold between cultivars and seasons; only an assay of the finished beer measures what is actually in a bottle.