Sticking at 1.020

[Hoppopotamus]

I've now done 4 all-grain brews. The first two were largely based on Marris Otter (e.g. Styrian Stunner) and they worked out fine. However the most recent two used larger amounts of speciality grains and neither got below 1.020 - the two beers in question were:

-Lazy Brew Ordinary Stout - see viewtopic.php?t=10614
-Bramling Beauty - see viewtopic.php?t=4936

I suspect that I'm doing something wrong in my mashing technique which is preventing the enzymes from breaking down the starches in the speciality grains. But what mistakes are likely to lead to this problem? E.g. should I be looking at mash pH?

All the mashes were between 67 and 69 celsius and none lost more than about 2 degrees over 90 minutes.

All brews were pitched with Safale 04 after being thoroughly shaken in the fermenter. All brews, including the ones that stuck at 1.020 tasted really good, so to some extent I could say that it doesn't really matter. However, I'd still like to know what I'm doing wrong.

[brewzone]

HPPM:

There's nothing wrong with Your technique!

Mashing above 65C will produce a beer/lager with a higher final gravity.

Lower than 65C will produce a more alcoholic beer/lager

For a pretty well balanced beer I usually mash at 65C +- 1C

/BZ

[prolix]

seems strange for safale 04 not to romp right through that lot. What is your water like? If you have really soft water it may be ph too acidic with all the dark malts.

I generally mash at 68 and saf goes down around 10 even with porters. you could try a longer mash with the darker beers but yours is no catnap atm anyway.

[mr bond]

HPPM:



For a pretty well balanced beer I usually mash at 65C +- 1C

/BZ

"Ditto"

Don't sweat it if it tastes good anyway, just try the next one with a lower mash temp and run that past your taste buds.

[Hoppopotamus]

Thanks for the replies. I will try mashing at 65C next time.

My water is not especially soft, and I have been adding 1 teaspoon of gypsum to my mash water anyway just to make sure. I will buy some pH papers and measure my pH on my next brew. At what level of acidity does pH start to have a detrimental effect on conversion?

[hoppingMad]

I would have expected them to finish a bit lower than 1.020 from the recipe I saw. 69 C is at the upper limit of what I mash at for an FG around 1.014 to 1.016 I did one recently at this temp which finished at 1.017, which is where I wanted to end up.
If you find the beer a bit sweet when drinking, try chilling the bottles (keg)a bit colder before serving, it helps to hide the sweetness to some extent.

Also you might want to check both your thermometer and hydrometer are acurate.

[MARMITE]

This has happened to me on several occasions for no apparent reason.Two recent examples.
1 Thomas Hardy Ale
OG 1093 mashed at 66 C pitched with 2 sachets of wine yeast.(Dave Line's receipe) When vigorous activity abated I quietly racked into demis and tested gravity 1065!! although very little activity.Intended to reairate and repitch per advice given on forum but only 1 sachet of yeast left and as it was a sunday I could'nt get any more .After 36 hours it suddenly started up again and has been bubbling away merrily for the last 10 days.
2Mild
OG1043 mashed at 66 C pitched with a sapale 04 starter made per Daab,s instructions and after 5 days no activity wort cleared and gravity at 1015.
Both worts well airated.
I know others on the forum say sapale 04 always gets down to quarter gravity stage and quickly but it does not always do it for me and I am left in the quandary of whether to bottle straight away or risk infection.

[Frenchie Laurence]

also happenned to me and the forum reassured me. I had used quite a bit of specialty grains too. I bottled it and it was fine, no explosion! nice and full taste. Less alcohol, more calories!