Mash Temperature Drop?

[alkos]

Is it ok to let the mash temperature drop, i.e. from 69C to 63C, within lets say 1 hour, and expect results as if it has been mashed at 66C? Or do enzymes working in the lower range are dentaurated already at the higher one (~ 70deg?)

 

[leiothrix]

it will still work fine. the main problem with such a wide swing is that you wont really be able to predict the body/sweetness of the beer as it will change markedly with the ambient temperature.

wrap your pot up with some cut up camping mat, old towels, blankets or whatever you have. Or maybe check the temp and give it a burst of heat every 15 minutes or so.

rob.

 

[Nick JD]

Because you started at 69C, 90% of the conversion will happen within the first 20 minutes, when it's probably dropped to about 67C.

The next 20 minutes it'll be at 67-65C ... and another 5% of your conversion will have happened.

Basically, if you're mashing at 69C and are getting your base malt cheap - there's not much point leaving it in there for longer than about 20 minutes.

If you are going for efficiency records then by all means leave it in there. Taking 40 minutes off your brewing schedule for $0.60c of malt is a win-win situation in my books.

If you start at 69C what you end at is moot. If you start at 63C ... that's another issue altogether - if you can't maintain that temp them you'll have ver bad efficnency. The big thing here is that you can't aim for 66C by starting high and ending low because your initial temp is the one that counts if it's high.

You'll get a very "heavy body" beer starting at 69C.

 

[bconnery]

I can't comment for certain on the chemistry of it all but my understanding is that the great majority of conversion occurs within the first 20-30 minutes so your temperature within that time frame is probably the most important.
Obviously the more consistent you can keep your mash temp the better however but I'm not sure of the overall effects of such a temperature drop.

Edit: as Nick JD said, but he had more to actually say than my perhaps maybe type of post...

 

[Tony]

Im no expert on the mash enzyme function over time relative to temperature but personaly i would say..... no.

I find when i infuse up from my protein rest at 52 to the mash rest in the 60's (63 to 67 usually in my setup) the mash is sweet within 30 seconds from stiring in the infusion water.

If you look at the specs for most good malts, they convert in 10 to 15 min. We mash for longer to ensure we have it all converted as most of us dont have a mash tun thats constantly being turned over and raked like a comercial unit.

Thirsty?

 

[alkos]

Because you started at 69C, 90% of the conversion will happen within the first 20 minutes, when it's probably dropped to about 67C. The next 20 minutes it'll be at 67-65C ... and another 5% of your conversion will have happened. You'll get a very "heavy body" beer starting at 69C.

the great majority of conversion occurs within the first 20-30 minutes

I find when i infuse up from my protein rest at 52 to the mash rest in the 60's (63 to 67 usually in my setup) the mash is sweet within 30 seconds from stiring in the infusion water.

Thanks guys! That answers the question better than enough.

Thirsty?

Hell yeah :icon_drunk:
(it's 11am in Ireland...)

 

[bconnery]

Thanks guys! That answers the question better than enough.

Thirsty

Hell yeah :icon_drunk:
(it's 11am in Ireland...)

In which case you should be drinking, that's way past beer o'clock in Ireland... but what I am guessing Tony was referring to was directing the question to ThirstyBoy who uses a lot of commercial malt and knows about how large scale commercial breweries operate for some reason...

 

[manticle]

Basically, if you're mashing at 69C and are getting your base malt cheap - there's not much point leaving it in there for longer than about 20 minutes.

Actually there is a [possible] point. I'm not experienced enough to give you the exact science but I've been playing recently with high mash temps and long mash times and I believe it does something different to low mash temp and usual mash time.

You end up with a good malty beer that still has a dry finish and attenuates well. I don't know how much is just my perception so someone with a bit more science may be able to explain it (or tell me I'm a moron - whichever suits).

Mashing high and long is done a lot with some English and some belgian beers so it's not completely baseless.

 

[boybrewer]

What are you using for a mash tun ?

 

[alkos]

In which case you should be drinking, that's way past beer o'clock in Ireland...

I would be. Its my job that stops me. <_<

but what I am guessing Tony was referring to was directing the question to ThirstyBoy who uses a lot of commercial malt and knows about how large scale commercial breweries operate for some reason...

Ha! :icon_cheers:

Mashing high and long is done a lot with some English and some belgian beers so it's not completely baseless.

I'm planning my first AG to be a Northern English Brownie, a really malty one. I'll try to keep 68-69 then... Or better not?

 

[alkos]

What are you using for a mash tun ?

Nothing yet, I'm buying a 40L urn for BIAB in a few days. Its stainless steel, I will insulate it with foam mat and measure the temp drop.

 

[Nick JD]

Mashing high and long is done a lot with some English and some belgian beers so it's not completely baseless.

If you can maintain the temperature, for sure. If it's rapidly dropping then you're looking at an enzymatic war with unpredictable results.

 

[Bribie G]

I get 1.5 degree drop, typically, using my 40L urn and double lagging it with a kids sized sleeping bag slipped over the top then the whole thing swaddled in a feather duvet and strapped. (link to article) So if I'm doing a 65 degree mash I'll start at 65.5 and let it drop to 64 with the idea being that the conversion mostly happens in the first part of the mash.

 

[felten]

Bubble wrap is a good insulator, throw a towel on there, bubble wrap, then a blanket or a cheap doona and you're set.

 

[Fourstar]

Just to throw another spanner into the works, having a falling mash starting at 69deg and falling to 63 over the hour might not be a bad thing. If anything it may increase the fermentability. let me explain.

At 69 deg you will have alot more alpha amylase activity chomping away at that starch matrix and breaking down 1-4 links. Why is this good? well beta amylase (the primary enzyme for maltose production) can only break down starches from the nonreducing end of the chain and has to stop once it gets close to a 1-6 link (fork/join in the chain). The alpha amylase, by breaking up the starch matrix "randomly", creates more non reducing ends for the beta amylase to bond to whcih are not connected to a 1-6 link, consequently more conversion to maltose occurs and fermentability increases.

Does this happen in a standard 65-69 deg mash anyway? Yes it does, but their might be some positive effects of allowing the amylases to work independently within their desired temperature ranges. The efficiencty of the enzymes may increase by encorporating this falling mash regieme.

Also, B Amylase doesnt just get annhilated once you exceed its temperature range, it has a falling off period before its fully denatured, although this happens quite fast above 70 deg.

The joys of learning stuff by studying cramming for the BJCP exam this Sunday! :icon_cheers:

 

[Bribie G]

Sort of like a step mash, but stepping backwards? Braden You'll cream them on Sunday :beerbang:

 

[Fourstar]

Sort of like a step mash, but stepping backwards? Braden You'll cream them on Sunday :beerbang:

yeah, kinda! a reversey step mash. :icon_chickcheers: Even better woudl be a slow raise, hold and fall. although i dont know if the B-amylse would deactivate by the time thats over.
:icon_offtopic:
Yeah its abit of hard work Bribie! The hardest thing will be regurgitating all the vital stats of styles. Who really remembers a Maibock has a OG range of 1.064-1.072 and a FG range of 1.011- 1.018?!?!

Atleast the hardest parts are over, i have 11 classic style example recipes pretty much memorised (including grain weights and hopping AAU/IBU figures) and majority of the intermediate malting and mashing techniques and 'sciency' technical information down. Tonight is onto classic regions and a commercial example/stlye from the region.

hard work is ahead of me!

 

[dr K]

Given the constraints that we work under "mash temperature" is not as important as some may say, given of course that we mash in the "range"(60-70C will do).
How do we determine our mash (starting) temperature, now whilst my thumb is an ok indicator I use a digital probe type thermometer (its out a fews points of a degree), now if even after a pretty decent dough-in my temp in the middle, measured at the top varies from that at the sides and if I drain some wort from the bottom (into an attemperated vessel) it different again, typically a few degrees lower, already throughout the mash tun I have a range of temperatures.
Even leaving that aside though are two often forgotten factors.
In order for the amalyse enzymes (beta or alpha) to work the starch first has to be gelatinized, good thing that barley starches gelatinize in the mash range, gelatinization continues throughout the mash, in fact full gelatinization is most likely not accomplished in a standard 60 minute infusion mash.
Secondly mashing (conversion) is an exothermic process.
From a practical homebrew point of view this probably means don't worry too much, sure a wort mashed at 69C may produce a maltier beer than one at 63C, but choice of grain bill, yeast, fermentation conditions, time and temperature in particular will have a far greater impact.
I suggest that an identical EBC and IBU beer mashed 60 minutes at 69C using Galaxy, light crystal and US-05 will not be as malty as a beer mashed 60 minutes at 63C using Munich 1, Melanoidan and say a WLP830 Oktoberfest.


K

 

[Fourstar]

From a practical homebrew point of view this probably means don't worry too much, sure a wort mashed at 69C may produce a maltier beer than one at 63C, but choice of grain bill, yeast, fermentation conditions, time and temperature in particular will have a far greater impact.
I suggest that an identical EBC and IBU beer mashed 60 minutes at 69C using Galaxy, light crystal and US-05 will not be as malty as a beer mashed 60 minutes at 63C using Munich 1, Melanoidan and say a WLP830 Oktoberfest.
K

Dr. K

Thats like comparing apples and organges.

One is the product of a higher dextrinous wort dependent on mash temperature, compared to one with a higher malt profile due to the degree of kilning on base and specialty malts. Thus, mash temperatures effect on 'maltiness' is irrelevant.

Flavour wise, what you put in is what you get out. The real effect is what the yeast has on the final product w/respect to attenuation and the amount of (body) dextrins left behind.

The only relationship they have is they are both affected by the app degree of attenuation due to the ratio of dextrins to fermentables depending on the mash regime decided upon.

Although i do get what you are saying, with majority of our setups there is alot of armwaving to how accurate our mash temperatures are. Unless of course you have a herms/rims setup and can assure yourself the temperatures are static throughout the entire mash regieme.

 

[Kai]

Two things here, Dr. K:

In order for the amalyse enzymes (beta or alpha) to work the starch first has to be gelatinized, good thing that barley starches gelatinize in the mash range, gelatinization continues throughout the mash, in fact full gelatinization is most likely not accomplished in a standard 60 minute infusion mash.

Are you saying a 60 minute mash may well leave starches behind?

From a practical homebrew point of view this probably means don't worry too much, sure a wort mashed at 69C may produce a maltier beer than one at 63C, ...

And I disagree with this. Wouldn't a higher mash temp leave greater residual body, not greater malt character? It's essentially like adding more dextrins and other complex sugars, not like adding the malty goodness that results from the malting process (And, to an arguably lesser extent, from the boil).