Brown Porter - What Went Wrong ?

[luckyeatwell]

Hi All,

I had a shot at brewing a Brown Porter a little over a week ago, this being my first attempt at AG with some new equipment (I'd previously borrowed a mates tun & kettle for my first 3 AG brews).

Due to an incorrect estimate at efficiency, my OG came out at 1060 rather than 1050. Not too stressed about this. Better efficiency can only be a good thing for the next brew, right !

My real problem however is that after a week in the fermenter maintaining between 19 and 22 degrees, the WLP-002 has done it's job and my FG is now sitting at 1011, maybe 1010.

Tasing the sample taken for FG reading, it tastes OK, but thin. A bit of fruityness from the WLP-002 but not overly alcoholic (well, it doesn't taste like its 6.4% !). It was a bit harsher (alcohol & bitterness) when I refrigerated the sample and tasted it chilled.

One of my questions is what did I do wrong to end up with 80% attenuation from a yeast that claims to deliver 70% at its best (according to White Labs) ???

The critical details here are:

mashed @ 68 Deg. C (dropped 1 degree over the 70 minute mash).
45L batch, estimated 75% efficiency

Recipe:
76% TF Marris Otter
13% Bairds Brown Malt
4% JW Chocolate Malt
4% CaraMunich 2
2% JW Amber Malt (in there just to be rid of it)
30IBU with additions of Challenger and Fuggles.

WLP-002. pitched from a starter equivalent of 3L of 1040 wort.

Batch Sparged with 3 x 15L volumes @ 80 Deg. C

Boiled down approx. 2L of the first runnings to a thick syrup to try gain an element of caramelisation.

I didn't mash-out as I thought that the combined med-high mash temp, 4% crystal and caramelisation would do the trick for me in keeping a bit of unfermentables in the wort. I thought wrong.

Any ideas toward retaining body for next time ?


Cheers,

Lucky.

 

[Stuster]

Yeasts can certainly attenuate more than the range the yeast companies give. You had a good amount of yeast there which can certainly mean a lower FG. From the tastes you describe, it doesn't sound like an infection which could certainly cause the final gravity to be lower. Next issue though is mash temperature. How sure are you that your thermometer is accurate?

 

[Maple]

WLP-002. pitched from a starter equivalent of 3L of 1040 wort.

How much of that starter was yeast? If it was a full 3L pitch of an ale yeast, wow... perhaps consult mrmalty.com for the pitching rates

 

[warrenlw63]

Tasty looking recipe Lucky... To be honest it's too easy to get hung up on numbers rather than flavour with attenuation. Give it a few weeks to round out and I'm picking you'll be doing that brew again.

Warren -

 

[crundle]

I would be trying to see how accurate the temperature is on your thermometer, and secondly how well you stirred the mash prior to taking your measurements.

Thirdly, it might be prudent to check the accuracy of your hydrometer by making up a suitable sugar solution at a 1.050 and 1.010 concentration. I will see if I can find the chart somewhere, but there was a topic on this on AHB somewhere!

Sounds like a great recipe nonetheless, I have recently made one using Jamil's recipe and found Brown Porter to be a perfect winter beer.

Crundle

 

[luckyeatwell]

Crundle,

Yep - I thought my hydrometer had something wrong with it, so I checked the FG again the next day with a different one, different test tube, same result though.

And yeah - my recipe is a variant of Jamils too. It looked awesome on the page. I just hope my 6.4% Beast Brown Porter hasn't lost the essence of what a good brown porter should be.

Warren,

I'm not put off by the taste out of the fermenter, and either way - It'll be consumed.... And then I'll just have to try another one.


Stu,

The thermometer was a good, scientific glass thermometer. My mate paid good $$ for it after we'd identified error in the cheap ones we were using. we've tested the calibration of the current one with a few "datums" and found it to be pretty spot on.


I guess I'm looking to try and avoid the mistake in the future so I can get the terminal gravity I'm after for the beer style being brewed.

Has any one had any sense of continued enzyme activity in the kettle, between sparges ? The idea being that the wort in the kettle is cycling between 60 and 70+ degrees as the various sparge additions accumulate (see above - 3 sparges). Thus the enzymes are allowed to continue to do their work, but over the full alpha and beta optimal temp ranges.
This is the only real idea we've got right now.

 

[Stuster]

Has any one had any sense of continued enzyme activity in the kettle, between sparges ? The idea being that the wort in the kettle is cycling between 60 and 70+ degrees as the various sparge additions accumulate (see above - 3 sparges). Thus the enzymes are allowed to continue to do their work, but over the full alpha and beta optimal temp ranges.
This is the only real idea we've got right now.

Yes, the enzymes will still keep working in the kettle. If it took a while to do those sparges and you didn't get the wort any hotter than about 70C then that might explain it.

Looks a good recipe though and should still be a tasty beer.