14 replies to this topic

[shaggaroo]

OK, so any one have a degradation rate for me? I'm interested in how much alpha acid is lost over time as maybe a function of temperature, though I keep my hops in the kitchen freezer. I think promash calculates this but I don't use promash as I'm on a mac. So any equation would be helpful then I can just throw it into Excel.Thanks,Jeff

[DaBearSox]

OK, so any one have a degradation rate for me? I'm interested in how much alpha acid is lost over time as maybe a function of temperature, though I keep my hops in the kitchen freezer. I think promash calculates this but I don't use promash as I'm on a mac. So any equation would be helpful then I can just throw it into Excel.Thanks,Jeff

i always use promash but I think different types of hops have different rates of degradation

[shaggaroo]

i always use promash but I think different types of hops have different rates of degradation

So in promash do you then put in what hop it is to look at the degradation?

[DaBearSox]

So in promash do you then put in what hop it is to look at the degradation?

exactly if you tell me what your using i can look in radical brewing and it gives a 1-4 rating of their stability

[shaggaroo]

I have a copy of Radical Brewing, I'll have to look in there... does the rating associate a certain % degradation with each rating?

[gnef]

In my mind, equations only give you a ball park, and you have to figure it out based on your experience. You don't know how the hops were stored before they got to you. Do you keep them vacuum sealed in the freezer? That can be an influence.I'd recommend using them in a test batch to see if the IBUs match to what you expected for that beer, and adjust accordingly.

[shaggaroo]

Yeah, I'm just trying to get a ball park compared to what they were in the past. I do keep them vacuum sealed in the freezer, so I'm hoping there isn't a ton of degradation.

[dondewey]

I think New Lager Brewing has a degredation schedule for a variety of hops (I think they vary a lot). Is there one in particular you are interested in?

[shaggaroo]

I was wondering about magnum and perle.

[dondewey]

Perle is supposedly one of the best keeping hops - 85% AA after 6 months at 20C. Nothing on magnum in the table, looks like 60% is average.

[chuck_d]

https://dieseldrafts...html#hopsscroll down past the IBU calcs for formulas and links about hops deterioration.

[shaggaroo]

Thanks Chuck! Just what I was looking for. Looks like a first-order decay, as I thought it would be.Prost!

[chuck_d]

Interesting piece of info, only homebrewers really care about different utilization factors based on time of addition. Probrewers use the same utilization factor for all kettle additions. So there is no Rager vs Tinseth debate, at least not as we were taught a couple weeks ago. The reason for this is probrewers might go up to 120 minutes from the end of the boil to chilled wort, while homebrewers might only take 15 minutes from flameout to pitching temp. So in the pro setting, even your 5 minute addition gets utilized. However, the 5 minute addition isn't subjected to an intense rolling boil for 60 minutes, so its aromatics don't get blown off like the 60 minute additions. Perhaps unfortunately for me, there weren't any recipe formulation questions on Friday's quiz.

[MyaCullen]

Perle is supposedly one of the best keeping hops - 85% AA after 6 months at 20C. Nothing on magnum in the table, looks like 60% is average.

ProMash gives Magnum 75% FWIW

[shaggaroo]

Thanks!