Beersmith 2 Calculation - Please Explain

[spiderwrangler]

So it really doesn't add anything to the calculations of your IBU's but allows you to put it in so that you remember to do it if you're following your brew day sheet...

[Buttwidget]

To clarify, when you specify "aroma" for the hops addion, it moves it to the end of your brew sheet and treats it as a whirlpool addition with no effect on calculated IBUs.

You should select "boil" for the hops additions that occur right up until flameout (it doesn't matter if you are calling them flavoring or aroma additions, specify "boil") and it will calculate how many IBUs will be added to the wort.

So this leads to a process question as I don't fully understand the hops isomerization process. Knowing what was stated above, when adding hops at flameout, should I select "boil" with a time of 0 or "aroma" with a time equivalent to the length of time spent chilling the wort?

Its so easy to make great beer, but man there are so many rabbit holes involved in understanding how you did it!

~widget

[CRBrewHound]

What is your chilling method?

I think if you are using an immersion chiller then I would use the aroma method as you will be chilling the volume in the kettle as a whole down to moderate temperatures fairly quickly and not converting the end addition to IBU's as readily.

If you use a counterflow chiller then the kettle volumes would maintain near boiling temps for a much longer time and will be utilizing those hop addions and adding a lot more IBU's as the volume of wort waits to get through the chiller.

[Buttwidget]

Good point. I use an immersion/whirlpool chiller and get down to about 140 degrees in 2 minutes. I haven't plotted the temp over time, but that might be a good way to see how long it takes to get below isomerization temperature. Then I can determine how I want to calculate it it out.

Happen to know at what temp the hops quit adding bitterness?

~widget

[anday6]

As it was discussed on a recent show and off and on for a while, whirlpool utilization and isomerisation is not yet defined. But as temperature decreases from boiling, your rate of isomerisation will decrease as well. Is this linear? Nobody knows if that experiment has been done yet. Also, the agitation of a whirlpool will affect that rate as well.

The current theory is to calculate an extended whirlpool as a late boil addition (10-20 mins) to get some idea of the actual bitterness. However this is just an approximation of wort IBUs and doesn't account for how many IBUs actually go into solution because calculated and tested IBUs always differ.

It's different for everybody. Learn what X number IBUs taste like on your system and that is the number you use as a benchmark.

[Buttwidget]

Yep. My current goal is to understand more exactly what the numbers are an how to control them more tightly throughout the process (if it can't be measured it can't be managed).

Those things that can't be measured will have to be controlled for. I'll concern myself with that aspect next.

Thanks for the great conversation BN Army.

~widget