IBU & HOP'S
opinion on IBU and hops.
(sorry my english)
I often find myself in a brewery working with young people who come from brewery productions. this phenomenon called BEER FIRM in Italy is very well known and now many guys try their hand at these activities.
There are several aspects that unfortunately are not included when one is a HomeBrewer but one above all is the calculation of the IBU and the different uses of the hops.
often I'm asked to throw hops to zero minutes with the belief that such aromatic waste does not release bitter (IBU). in the housewarming concept, a zero-minute throw is carried out by means of a bag which is immersed in the flame-out must and removed immediately as if it were a tea bag, with times below one minute.
in brewery this does not happen and the hopping process is substantially very different. let's analyze why:
we assume that the isomerization of the alpha acids occurs at temperatures above 80 ° C, this means that any hop inserted in the must also with a short time releases a bitter amount related to the time and to the alpha acids of the hop itself. the hops throw at ZERO MINUTES do not RETURN ZERO IBU !!!
the key factors to keep in mind are:
liters
must density
alpha acids of the hop
time
in brewery production the boiling time varies from 60 minutes to 120 minutes (depending on what is being produced), but at the end of this time do not take the hop bags out at home !!! the hops are thrown free in the must and after the boiling time the process called WHIRLPOOL begins with an approximate time of 15 minutes. at the end of the whirlpool the must must be stopped in order to convey the hops to the center and usually (as far as my experience is concerned) I have to wait another 15 minutes before I can start to cool the must.
the temperature during the whirlpool is ALWAYS OVER 95 ° C ALTHOUGH WE ARE IN A FLAME OUT SITUATION.
so the calculation of IBUs as you understand well does not follow the timing of housewives !! and the same recipes must be revised.
if you want to have a beer that is as similar as possible to the one made in a brewery, start hopping without a bag and at the end of boiling time, run a whirlpool using a small pump or stirring the must with a spatula to create a voritce ... this point wait for it to stop and wait as I said 15 to 30 minutes before starting to cool.
in this way you will have a more truthful timing on the hopping and the extraction of the alpha acids.
rely on the brewer who will make your recipe, give him a taste of your homemade product and see the recipe together. explain how you built it this way and how to adapt it to your production facility.