Mash Temp And Fg

[hockadays]

Hi guys ,


Up to around my 5th AG and still learning heaps every time. This time while making an Irish Red ale I mashed at 68degC for one hour then mashed out at 72deg for 10mins and then batch sparged at 75deg letting it rest for 30mins before running off.

The OG was 1.049 in the fermenter and after its fermented and I racked it to secondary it looks like its going to finish up at around 1.017. Seems a little high for me but is this cause I mashed at 68degC. I used S04 for the yeast as I could not find a wyeast suitable. I tasted it and it dosen't taste sweet. Has anyone had the same sort of result when mashing at this temp.
Also could the crush have anything to do with it. Crush seemed a little course.

matt :unsure:

 

[enoch]

I had a couple brews with an old thermometer as I couldn't find the usual. Diddn't check the accuracy until I had two ~1050->1020 brews in a row. Checked thermometer and it was a few degrees low so the 65 I thought I was at was more like 68-69.

New Thermometer and mashing at 63-64 has given me 1050 plus -> 1010 last couple brews.

Mash thickness can also be an issue can't remember which direction though!) but 68C will give you a very full bodied brew.

Enoch

 

[KoNG]

if i mashed at 68*C on my system i would expect an FG of around 16 or 17. It's amazing what difference even 0.5*C makes....
Did you also use much crystal or cara-pils.?

 

[hockadays]

I might have to do a check on my thermometer but I think it's good.
My mash was a start of 2.6l/kg and up to 3l/kg at mash out..Maybe that has something to do with it as well. I only mashed for 60mins as well should I have mashed for say 90min..

I also used around 200g of crystal 135L
250g of wheat
100g munich
4kg pale
50g roast barley

matt

 

[KoNG]

Matt, as i said you could expect around that FG.. so dont be too concerned (if it tatses good, be happy.. most people would brew an irish red and be bummed it went all the way down to 1.010). Also i have noted that S-04 has a tendency to drop out of sol'n and form a brick in the bottom of the ferm, a slight swirl, shake or stir might aid in you getting a few more points if you can keep it in suspension. Fermentation temperature at this time of year might also be worth looking at.

 

[Darren]

I might have to do a check on my thermometer but I think it's good.
My mash was a start of 2.6l/kg and up to 3l/kg at mash out..Maybe that has something to do with it as well. I only mashed for 60mins as well should I have mashed for say 90min..

I also used around 200g of crystal 135L
250g of wheat
100g munich
4kg pale
50g roast barley

matt

[post="129391"][/post]​

Hey Hockadays,
Not sure where you are situated? If you are about the go into "winter" then it could be your overnight temperature that made it stop. I don't think it is your mash regime, more likely a yeast problem.

cheers

Darren

cheers
Darren

 

[hockadays]

thanks guys,,

I'm in brissy..
There was a bit of a cold snap that went through the other night. It was brewing at 20deg and didn't get below 18degc in the fridge it's in. The yeast did drop out real quick so I gave it a stir and racked and raised the temp up to 24deg to see if it would go again and it dropped a few more points to 1.018. Tasting it just now and there is a little residual sweetness there. Don't know if it would be worth putting more yeast in to get a couple more points. I was aiming for it to finish around 1.014..

matt

 

[Darren]

What time frame are you talking, days, weeks?

cheers
Darren

 

[stephen]

When mashing you have two enzymes at work: Alpha and Beta amylase. These emzymes work optimally at different temps and produce different results. I can't remember which works at what temp at this point, but if you mash at 60 deg then you will produce more fermentable sugars and end up with a lower FG reslting in a drier beer with higher alcohol content but somewhat lacking body.

Conversely if you mashed at 70 deg you will produce a lot more unfermentable sugars (maltodextrine) that will result in a higher FG with a sweeter or cloying taste, lower alcohol and more body.

Hence you will often see mashing temps around the 65 degree mark.

This is from the decaying grey matter.

Guess I'll have another beer,

Steve

 

[Darren]

Hey all,
And that is why you should add water to grain not grain to water.

cheers

Darren

 

[Hogan]

Darren

You have said this previously. I would appreciate knowing what you base this on before I go adding water to grain or grain to water. Seems that grain to water may give a harsher temperature introduction for the grain but water to grain could produce an inconsistant mix and pockets of varying temp.

Cheers, Hogan

 

[hockadays]

darren
time frame for fermentation was 4 days till I racked.

I know it's only a couple of points and it's within the style but I like to know why things don't happen as planned. I first thought yeast problems but then thought maybe mash. May be a combination of both...

Do you think dropping a yeast at this stage is too late. Its been in secondary for 2 days now.

 

[MHB]

These are the critical temperatures for mash brewing.

I have lifted this from a book but if you want to have control of the mash process these temperature steps are worth committing to memory.

40C A temperature stepped mash is sometimes started at this temperature, particularly if cooked cereals are to be added to the mash which would raise its temperature close to the optimum for proteolysis. Some German brewers stand the mash at this temperature for 24-48 hours to encourage lactic acid bacteria to grow and acidify the mash.

50C Optimum temperature for the protein rest, where (122F) proteolysis and some amylosysis takes place. Most temperature stepped mashes are started at this temperature. It is very tolerant, anywhere between 45C and 55C will give satisfactory results. Standing period can be anything from 15 minutes to one hour depending upon quantity of starchy adjuncts in the grist.

60C Optimum temperature for beta-amylase activity which converts starch into fermentable sugars. A beer mashed entirely at temperatures close to this would be fairly dry and relatively high in alcohol.

65C Optimum temperature for diastase activity which refers to alpha-amylase and beta-amylase working together synergistically. A beer mashed entirely at this temperature would have a well balanced ratio of fermentable to non fermentable sugars.

70C Optimum temperature for alpha-amylase activity which converts starch into non-fermentable dextrins. A beer mashed entirely at a temperature close to this value would be high in body and mouth-feel, but relatively low in alcohol.

76C Optimum temperature for liquefaction which reduces wort viscosity and aids mash tun run-off. Arrests beta-amylase activity but permits some alpha-amylase activity.

78C Typical sparge water temperature.


Good Brewing
MHB

 

[stephen]

MHB

That's what I was trying to say earlier in this thread.

steve

 

[Darren]

darren
time frame for fermentation was 4 days till I racked.

I know it's only a couple of points and it's within the style but I like to know why things don't happen as planned. I first thought yeast problems but then thought maybe mash. May be a combination of both...

Do you think dropping a yeast at this stage is too late. Its been in secondary for 2 days now.

[post="129423"][/post]​

Hockadays,
4 days is a bit quick for 1.050. You probably should have left it for a week before transfering to secondary. After all it allows some of the crap to drop as well as getting those final couple of points.
I think everything has gone exactly as it should have and will probably drop thise last couple of points over the next two weeks.

cheers
Darren

 

[Darren]

Darren

You have said this previously. I would appreciate knowing what you base this on before I go adding water to grain or grain to water. Seems that grain to water may give a harsher temperature introduction for the grain but water to grain could produce an inconsistant mix and pockets of varying temp.

Cheers, Hogan

[post="129419"][/post]​

Hogan,

I have posted this before and some have disageed with it so take it with a piece of salt.

You are right that adding grain to hot water will virtually kill all of the b-amylase (low temp enzyme converter) in the grain that hits the hot water first.

If you look at MHB's "grab" you will see that the what is quoted in the text are optimal, not critical enzyme temps. A "critical" enzyme temp would be described as one that irreversibly denatures the activity of that enzyme. Optimal is the one that the enzyme works its best.
If you hit the malt with hot water the B-amylase will be irreversibly "killed" as 73-75C is above its "critical" temp tolerance.

Adding the water from below the grain produces almost no clumps of grain and IMHO is gentler on the malt.


cheers

Darren

 

[Darren]

These are the critical temperatures for mash brewing.

I have lifted this from a book but if you want to have control of the mash process these temperature steps are worth committing to memory.

40C A temperature stepped mash is sometimes started at this temperature, particularly if cooked cereals are to be added to the mash which would raise its temperature close to the optimum for proteolysis. Some German brewers stand the mash at this temperature for 24-48 hours to encourage lactic acid bacteria to grow and acidify the mash.

50C Optimum temperature for the protein rest, where (122F) proteolysis and some amylosysis takes place. Most temperature stepped mashes are started at this temperature. It is very tolerant, anywhere between 45C and 55C will give satisfactory results. Standing period can be anything from 15 minutes to one hour depending upon quantity of starchy adjuncts in the grist.

60C Optimum temperature for beta-amylase activity which converts starch into fermentable sugars. A beer mashed entirely at temperatures close to this would be fairly dry and relatively high in alcohol.

65C Optimum temperature for diastase activity which refers to alpha-amylase and beta-amylase working together synergistically. A beer mashed entirely at this temperature would have a well balanced ratio of fermentable to non fermentable sugars.

70C Optimum temperature for alpha-amylase activity which converts starch into non-fermentable dextrins. A beer mashed entirely at a temperature close to this value would be high in body and mouth-feel, but relatively low in alcohol.

76C Optimum temperature for liquefaction which reduces wort viscosity and aids mash tun run-off. Arrests beta-amylase activity but permits some alpha-amylase activity.

78C Typical sparge water temperature.


Good Brewing
MHB

[post="129445"][/post]​

MHB,
Those temps are not critical! It all depends on the relative amounts of each of the enzymes present in particular batch of malt. Some malts will happily convert at 68-72 others will not convert above 66. The take home message should be, once you go above the inactivation temp of any enzyme it is irreversibly denatured (killed).

cheers
Darren

 

[wessmith]

Darren, you are attempting once again to rewrite many hundreds of years of brewing practice with your ill informed comments. The best thing you have said tonight is to "take it with a bit of salt" Sound advise, but PLEASE stop alarming the newer mash brewers witrh this pedantic enzyme denaturing nonsense of yours. It simply does not happen in practice. Go ask any pro or micro brewer.... Jeez!

Wes

 

[Hogan]

Darren

Can't see the difference in underletting and sprinkling (grain to water) - both methods will have water strike the first grains (either coming up through the bottom inlet or grains dropping down from the surface) Either way the first grains wetted will receive the higher temp and the addition of further grain will reduce the water temp just by its volume.

I did not say "adding grain to hot water will virtually kill all of the b-amylase (low temp enzyme converter) in the grain that hits the hot water first."

I dont have any expertise on low temp enzyme coversion. But I would think that pouring hot water onto a tun of grain would kill as much if not more b-amylase than underletting or sprinkling. IMO.

Thats my grain of salt FWIW.

Cheers, Hogan.

 

[Hogan]

On ya Wes.