Just to revive this thread, I've just done a brew today and discovered that my Hanna thermometer reads about 4C lower at mash temperatures than another (cheap Ikea) digital thermometer and my spirit thermometer. Going by the law of averages, it's the Hanna one that's out.
So this means that the last few brews I've done have probably been mashed about 4C hotter than I expected - somewhere around 70C most likely....
Although the underpitching discussed earlier in this thread is probably the main factor, I'm still likley to have ended up with more dextrins in the wort than I though, right? Which could also be part of the problem...
Oh well. The Hanna is going off for a proper, certificated (and bloody expensive at £30) calibration tomorrow at the factory. I have no idea when it was last done, but 4C seems an awful big error for an instrument that's meant to be accurate to 0.1C. Maybe it's faulty.
Lucky I only paid £12 for it or I'd be seriously pissed off.
Mash Temp vs. Fermentability
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mysterio
Re: Mash Temp vs. Fermentability
Like you say it's probably played a part but the difference will only account for a couple of points of gravity - unless you were mashing completely out of the enzymatic range.
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adm
Re: Mash Temp vs. Fermentability
Life's a bitch isn't it. I'm just going to have make more beer for research purposes.....
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adm
Re: Mash Temp vs. Fermentability
Ah well.....just trying to justify my crap brewing techniques.Chris-x1 wrote:Even mashed at 70 I still wouldn't expect it to cause the porter to stop at 1020.
I've got all this less than perfect beer to get rid of as now it has to be replaced with nearer perfect beer in my continuing quest for the ultimate pint.
I don't know what I'll do with it.....
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martinr
Re: Mash Temp vs. Fermentability
Dear Adm,
I think a greater power is at work with this high final gravity malarky. I have always ended up on the high side over the past 18 years (1010-1015) but my last 4 brews have all stalled at 1020! My experiment was to try SO4, Windsor and Wyeast 1968, and all stopped of them stopped at this gravity, even with what appeared to be text book fermentations. The mash was conducted at 65-67C, 90mins, and my calculated efficiency was 81%, which is pretty good I think. Im wondering if its linked to one single sack of malt I have, although then why should my efficiency be telling me otherwise??
It's a free pint tothe fella who can figure this one out. Mr. Flack, you know who I am, what's the answer then??
Cheers
MartinR.
I think a greater power is at work with this high final gravity malarky. I have always ended up on the high side over the past 18 years (1010-1015) but my last 4 brews have all stalled at 1020! My experiment was to try SO4, Windsor and Wyeast 1968, and all stopped of them stopped at this gravity, even with what appeared to be text book fermentations. The mash was conducted at 65-67C, 90mins, and my calculated efficiency was 81%, which is pretty good I think. Im wondering if its linked to one single sack of malt I have, although then why should my efficiency be telling me otherwise??
It's a free pint tothe fella who can figure this one out. Mr. Flack, you know who I am, what's the answer then??
Cheers
MartinR.
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adm
Re: Mash Temp vs. Fermentability
Hmmmm.......
I'd pretty much put it down to underpitching yeast.....but now you mention it, the last few beers I've made have all fermented out beautifully and were made from a new sack of malt!
Maybe a combination of both, but happily it seems to be a problem that's in the past now (fingers crossed).
I'd pretty much put it down to underpitching yeast.....but now you mention it, the last few beers I've made have all fermented out beautifully and were made from a new sack of malt!
Maybe a combination of both, but happily it seems to be a problem that's in the past now (fingers crossed).
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Gurgeh
Re: Mash Temp vs. Fermentability
Hello Martin,martinr wrote:Dear Adm,
I think a greater power is at work with this high final gravity malarky. I have always ended up on the high side over the past 18 years (1010-1015) but my last 4 brews have all stalled at 1020! My experiment was to try SO4, Windsor and Wyeast 1968, and all stopped of them stopped at this gravity, even with what appeared to be text book fermentations. The mash was conducted at 65-67C, 90mins, and my calculated efficiency was 81%, which is pretty good I think. Im wondering if its linked to one single sack of malt I have, although then why should my efficiency be telling me otherwise??
It's a free pint tothe fella who can figure this one out. Mr. Flack, you know who I am, what's the answer then??
Cheers
MartinR.
I know who you are too!
Might I be impertinent enough to enquire about rousing, temperature (possible dips overnight) and whether your water occasionally comes from boreholes? Earlier in this thread it was mentioned that water chemistry can make yeast drop out quick.
Of course, what with several people noticing a problem with SO4 recently, could it be the yeast itself being of a poor quality.
would you get the same result using nottingham?
Pete G
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steve_flack
Re: Mash Temp vs. Fermentability
I've been wondering that as well. The two latest beers I've made containing some of a certain sack of pale I've got have all stopped early despite low lag-times, decent extracts etc. My last 1.037 bitter stopped at 1.020 (!!!!) - my other beers with other malts are fine. I'm thinking of ditching what's left of the sack....martinr wrote: Im wondering if its linked to one single sack of malt I have.
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Gurgeh
Re: Mash Temp vs. Fermentability
Wet summer.... risk of crops rotting.... fungicide???????
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steve_flack
Re: Mash Temp vs. Fermentability
I'm not sure - I've had the sack a while (since March) and I can't recall it being junk when I opened it. It's been kept dry and this summer was hardly warm so I'm surprised if it's turned. I'm checking my thermometers at the mo to see if there miles out. I doubt that though as other beers made with other base malts have been fine.