Ibu's From Non-hop Sources

[Benchish]

In ye olde days many beers were brewed without hops using other herbs for bittering, flavour and other properties (medicinal or recreational)

So 2 main questions:

1. Im assuming that most of these herbs/spices would contain a different bittering compound to iso alpha acid (hops) so could they be tested in the same way? (this one is more theoretical as getting solutions tested is probably out of my price range)

2. Has anyone seen/have any info on what levels of bitterness to expect from different herbs? i figure there would be seasonal variation as in hops but there should be some ball park numbers or ranges (i.e i haven't seen EKG hops at 11%AA)

I figure my best bet for calculating bitterness ranges would be to do test batches taking samples at different boil times. Then taste testing them against iso-hop solutions at a known bitterness. That should give me a rough guide but it will still leave many variables like efficiency in different gravity.

 

[Muscovy_333]

Industrially the food industry would use GC or mass spec to quantify a known compund by molecular weight.

They also quite often use trained tasters and would basilcally compare with a reference sample as you suggest. (even better if it is a few tasters)
Your threshold for tasting will be different from the next person albeit consistent enough if for your own purposes.

On the topic, i have often wondered how much bitterness is contributed by certain garin types, particularly for high brewhouse efficiency batches where a lot of tannin is drawn through.
Other bittering compounds may not have the same preservative effects as the hop essential oils...something to consider, although i could not qualify this with any data.