Hop Utilisation figure in BeerEngine for specific boiler?

[WishboneBrewery]

Is there any way to work out the Hop Utilisation factor of my stock pot boiler?

In BeerEngine the Base utilisation is 39.75% What bearing does this have on the calculations?

The general consensus at work is that my beers aren't as bitter as my BeerEngine Recipes state, so 44IBU might be closer to 34IBU etc

Cheers

[Graham]

It is not possible to work out the utilisation of your boiler without a fully equipped laboratory. Maybe a stock pot would have a lower utilisation if it is on a hob and the hob is struggling to keep up a rolling boil.

The Base utilisation is set to 39.75 to match the Tinseth numbers. I do have issues with the thinking behind the Tinseth formula, even more so after listening to a podcast in which he appeared not to know how alpha-acid is measured, yet claims to have personally measured dozens of samples. It is included because lots of people use it, and it is better than most of the other formulas anyway.

If you lower the 39.75 number the quantity of hops will increase and hence the bitterness of the beers. The shape of the curves will remain the same as Tinseth, just that the maximum level will be lower.

[WishboneBrewery]

No straight answer then, just mess with the % numbers until someone else's comprehension of what 35IBU tastes like matches the figures in BeerEngine

My Stockpot sits across 2 Gas jets on the hob at the moment and I do get a good rolling boil. Eventually I'll have the boiler on its own Large Gas burner or fitted with the 3kW element I have. If I get it on a large burner I may have to make a baffle so as to leave one side of the Stock Pot a bit cooler to increase the rolling action.

Cheers

I wonder if bitterness could be measured in the Scoville Heat sense like with Chillies http://en.wikipedia.org/wiki/Scoville_scale yet it would still be very subjective.

[nobby]

From what I have read and my experiance there are several other things that can effect Bitterness

1. Your Water. Diffrent waters effect the final bitterness.
2. Diffrent Yeasts. WLP002 will mask the hops more than say WLP005. DIffrent Yeast give a diffrent final gravity. The high the more it will mask the Bitterness.
3. The length of times its been matured. Beweries dont mature their beer that long. The longer its matured the less bitter the beer.
4. Inconsitances in the Hops alpha-acid. We only use very small amounts and they only measure samples. So it could be very easy for the hops in your packet to be a completly diffrent strength.

[WishboneBrewery]

Fair points, though I've not had a yeast reduce the bitterness but I've had them suck out hop flavour and aroma.

[boingy]

I've always suspected that the AA of any particular bag of hops can be quite different from the number printed on the packet. The number is not amazingly accurate to start with and then there is the variation in storage and processing that the hops experience before we get them. Microbreweries probably get a more consistent quality of hops than we do, simply because the hops have travelled via less middlemen. I'm also not sure that my tastebuds are capable of judging the IBU of a finished beer with any great consistency from day to day.

[WishboneBrewery]

The sheer volume of hops used will also average out any differences in AA throughout the bale of hops I suppose too.
I'm tempted to set my BeerEngine utilisation to 30% and see how things go... Or... just ignore it and keep brewing good beer without actually bothering about the technicalities

[nobby]

just ignore it and keep brewing good beer without actually bothering about the technicalities

You have hit the nail on the head. Too many people take it too seriously on here. If you like it drink it and brew it again

[Bloozrocker]

Totally Agree Been brewing for thirty years now without the need of a Lab Coat.

[nobby]

Totally Agree Been brewing for thirty years now without the need of a Lab Coat.

That is a really good way of putting it "Lab Coat" I like it. Yes too like to "top trump" you all the time.

[boingy]

I actually quite enjoy the variation I get between batches. It would make me a terrible commercial brewer but I mostly brew for me and I like the fact that each batch of the same recipe is a bit different. Um, does that make me weird?

[WishboneBrewery]

its evolution

[mysterio]

I use Tinseth because it's the most robust I reckon, nowhere near perfect though. I agree it does tend to overestimate bitterness slightly. I just accept the first time I brew a recipe it's not going to be 100% how I planned. The second time I can adjust accordingly. Most of the time I'm just going for a middle of the road bitterness though and Tinseth works fine for that. Just don't put in lots of high alpha hops at 0 minutes

The length of times its been matured. Beweries dont mature their beer that long. The longer its matured the less bitter the beer.

Even finings pull out bitterness (isinglass, gelatine), quite a substantial amount when I use them.