How long to cook at turkey for at low temperature in a convection oven?
I've never cooked anything that low and slow in a convection oven.
But a cursory lookabout led me to this Sysco chart,
https://impacweb.cbord.com/reportsets/~common/Cooking%20Times%20For%20Convection%20Oven.pdf
There is a section for whole turkey 16 to 20lbs, 275-300F, for 4-5 hours.
But more importantly a note at the bottom states,
&quot;For menu items not listed, use recommended time and temperature for conventional oven but reduce the temperature setting by 25-50 degrees F and reduce the total bake/roast time by approximately 10 to 15 percent.&quot;
So if I were you using that recipe, I'd do 420F for 40 minutes, then 140F for 45m/lb, adjusting the time and temp by intermittent temperature checks.
Looking at a couple more sites and conversions those numbers from Sysco appear to fall in line. That's if the oven goes that low I'd imagine, 140F is pretty low.