Mash time/temperature, possible to pre-determine fermentability?

[slash22000]

G'day all,

So we all know that a higher temperature results in a less fermentable wort, and we know that a longer mash results in a more fermentable wort, but is there any way to determine exactly what the effects will be? Some software out there? Or is it just trial/error?

I normally brew dry, hoppy concoctions so I usually go for a dry beer, mashing low and long (66ºC, 90 minutes) and it's been working well (usually >80% efficiency). I'm looking into making some malty beers that need to finish sweeter, however I like the 90 minute mash for the sake of efficiency.

The recipe I'm looking at (oatmeal brown ale) recommends mashing at 68ºC for 60 minutes. Mashing for 90 minutes will end up with a drier beer. Looks like this test jumps from ~84% attenuation to about ~87% attenuation mashing for 90 minutes rather than 60, which is a pretty big difference.

Should I increase the mash temperature to facilitate the efficiency of a 90 minute mash without increasing fermentability, or just swallow whatever drop in efficiency and mash for 60 minutes at the recommended temperature? :unsure:

 

[Liam_snorkel]

G'day all,

So we all know that a higher temperature results in a less fermentable wort, and we know that a longer mash results in a more fermentable wort, but is there any way to determine exactly what the effects will be? Some software out there? Or is it just trial/error?

Ianh's BIAB spreadsheet includes an adjustment for mash temperature, but I'm pretty sure there was some trial & error in it's formulation. There might be some info in the corresponding thread on how he came up with it.

 

[slash22000]

Thanks Liam. Looks like every +1ºC mash temperature corresponds to ~1 extra point of FG to the recipe I'm looking at, but mash time doesn't seem to be changing anything. Will have to investigate further.

 

[JDW81]

however I like the 90 minute mash for the sake of efficiency.

Why are you reluctant to have a slight drop in efficiency?

 

[bum]

Why are you reluctant to have a slight drop in efficiency?

Higher efficiency == better beer.

Duh.

 

[slash22000]

It's more that I'm reluctant to drop efficiency if I do not have to. If I could achieve the same result with higher efficiency, it's obviously what I would want. It seems like it's probably not possible to pre-determine though, so I will probably end up sticking with the 60 minute mash and seeing how we go.

 

[Adr_0]

Don't think there is, and don't know how accurate Beersmith etc. is for predicting your FG based on mash temperature(s). The Hochkurz is meant to allow you to govern the balance of fermentability and mouthfeel, by essentially having a separate mash step for each peak of beta- and alpha-amylase activity.

The only way to really understand the fermentability of your wort is to do a fast-ferment test, and record your results as best as possible (times, temps, volumes, tasting notes).

Check out Braukaiser for both.

 

[Liam_snorkel]

I found these threads with a bit of discussion relating to that:
http://aussiehomebrewer.com/topic/43419-a-25-minute-mash-at-70c/
http://aussiehomebrewer.com/topic/66967-experiment-time/

 

[Bribie G]

I had a brief conversation a couple of years ago with Rob of BrewMate fame about whether this feature would be available and, after also skimming some learned treatises on the subject, it became apparent that it was - as Ian found - pretty much trial and error and examination of Bulls' entrails to see what the Gods had in mind for the mash, seems to depend on a complex set of variables apart from temperature and mash lengths. Add adjuncts to the mix and it might be a useful project for Einstein, if he were still with us. I seem to remember he put the bubbles in beer???

 

[JDW81]

might be a useful project for Einstein, if he were still with us. I seem to remember he put the bubbles in beer???

He had an awesome guitar too.

It's more that I'm reluctant to drop efficiency if I do not have to.

Fair enough.

Although IMHO a drop in efficiency isn't an insult to one's manhood, it is just something that can occur when we use different processes/aim for a different result. If it means you achieve what you are after (Maltier and sweeter beer) then maybe a small drop in efficiency is a small price to pay?

Have you thought about a step mash? It could help get you the maltiness you're after without a hit to efficiency.

JD

 

[slash22000]

I've never tried a step mash, but I can't imagine it would be difficult, I BIAB in an urn and can raise the temperature whenever I want (bag is raised off the element with a colander). I've done some reading on the subject of figuring out a step mash schedule but I think I might need a PHD or something first. h34r:

 

[Bribie G]

An excellent one is the German Hochkurz mash - 40 mins at around 63 - 40 mins at around 72 then raise to a mashout at 78.

Dead easy in an urn with BIAB and just involves re-wrapping the urn for the second step. Apart from that it comes at no cost as you are going to run the urn temperature up anyway to achieve the boil. Helps to have a big paint stirrer shaped like a potato masher, from the Dulux shops.

 

[slash22000]

An excellent one is the German Hochkurz mash - 40 mins at around 63 - 40 mins at around 72 then raise to a mashout at 78.

Dead easy in an urn with BIAB and just involves re-wrapping the urn for the second step. Apart from that it comes at no cost as you are going to run the urn temperature up anyway to achieve the boil. Helps to have a big paint stirrer shaped like a potato masher, from the Dulux shops.

Would this be appropriate for a sweet, malty beer? It is an English brown with oats, aiming for a smooth mouthfeel and relatively sweet. I don't suppose there is a list someplace with appropriate step mash profiles by style?

Good tip with the paint stirrer, I only just bought one and used it with my last BIAB, 500x easier to stir the mash than with the spoon I was using before.

 

[Bribie G]

English ales only need a single infusion mash followed by a mashout if you like. The idea of the German decoction mashes and stepped mashes was to "coax" the enzymes in the rather poor Continental malts whereas the "better" British malts would work fine in a single infusion.
Nowadays with modern agriculture the German and Euro malts are a lot better, which is why they no longer go in for decoction much in the big breweries, and have abandoned the acid rest and the protein rest, going straight into low 60s for the sacch. rest.

I'd go for a 68 mash for your brown and heaps of crystals.

 

[Bizier]

There are also factors such as the various parameters of the malt specifications.
Here is a decent little article on malt specs.
Plus there is the effect of your water and water adjustment additions, and the effect of the ratio of liquor to grist.
AND all effects affect each other, so it becomes immensely complicated.

Extreme example for illustration:
Thin mash of 4:1 LG using only Munich malt in very soft water
Stiff mash of 2:1 of high DP domestic pils malt in an appropriately buffered water with an ideal amount of calcium

I think you could come up with some "rule of thumb" numbers for average accepted good practice parameters, but it still will come down to individual circumstances and idiosyncrasies of equipment such as mill type and mash tun thermal mass, plus the heating capacity for mash tun rise times. If I brew a triple batch, I know my HERMS is a lot less reactive compared to say a multi-zone steam jacketed mash tun with an agitator.

 

[tanukibrewer]

Some good points to consider for my next brew

 

[MartinOC]

Ah, Slash! Welcome to the wonderful world of AG brewing! There's no "right" or "wrong" answer - it's all about what's right for YOU.

There are too many variables involved to make a definitive, catch-all response to your query & even if there WAS one now, it would change with next year's batch of malt, just to keep you on your toes & perpetually chasing the nirvana you seek.

Don't worry about extract/brewhouse efficiency. If you lose a couple of percentage points in efficiency & make a superb beer anyway, just what you were aiming-for, would you still call it a failure, or pat yourself on the back for nailing your target beer? I disagree with BUM on this one & wholeheartedly agree with JD.

The important thing is that you've already got a handle on your ingredients & know how to manipulate the variables to achieve a target h34r: . You might not nail it first time, but you'll still make good beer (I Hope!!) & can adjust your water chemistry/ingredients/adjuncts/mash regime/hopping schedule/fermentation schedule/packaging/storage/carbonation/serving variables accordingly... :unsure: NEXT time!

This is bucket-chemistry, not rocket-science!

Look on the bright side, mate - beer is (usually-there's another variable!) much quicker to mature than wine to know if you've hit the jackpot or not & make adjustments for the next batch.

Geez! I hope I haven't scared-off any newbie AG-brewers with this post!!!!

 

[manticle]

G'day all,

So we all know that a higher temperature results in a less fermentable wort, and we know that a longer mash results in a more fermentable wort, but is there any way to determine exactly what the effects will be? Some software out there? Or is it just trial/error?

I normally brew dry, hoppy concoctions so I usually go for a dry beer, mashing low and long (66ºC, 90 minutes) and it's been working well (usually >80% efficiency). I'm looking into making some malty beers that need to finish sweeter, however I like the 90 minute mash for the sake of efficiency.

The recipe I'm looking at (oatmeal brown ale) recommends mashing at 68ºC for 60 minutes. Mashing for 90 minutes will end up with a drier beer. Looks like this test jumps from ~84% attenuation to about ~87% attenuation mashing for 90 minutes rather than 60, which is a pretty big difference.

Should I increase the mash temperature to facilitate the efficiency of a 90 minute mash without increasing fermentability, or just swallow whatever drop in efficiency and mash for 60 minutes at the recommended temperature? :unsure:

What efficiency are you measuring? Brewhouse efficiency? Mash efficiency?

Generally it's one of the last numbers I would worry about apart from being able to read your system and work out recipes or adjust other recipes to your system. As long as it's not stupidly low, I'd concentrate on consistent efficiency rather than high efficiency. The difference between 84 and 87 on a home system is probably 100g of grain.

66 is not actually low although if it's giving you the results you want then great. You could get a beer as attenuative with a lower mash and less time - try 64 or 62 for 60. Mash efficiency might drop mildly (I doubt by much, if anything) but it's efficient use of your time.

For maltier, fuller bodied beers you can be even more efficient with time and mash at 69 or 70 for only 30 minutes.

What you are chasing is a complicated formula that will be dependent on grain type, liquor to grist ratio, mash pH and mineral content and so on.

If you're in it for the nerd points, keep searching and maybe try a few controlled tests of your own. If you're in it to make good beer, just trial and error and don't sweat 3 points of some kind of efficiency.

 

[Bribie G]

Actually it is possible to accurately control all aspects of your brewhouse and predict within a few hundredths of a percent what the finished beer is going to be like, its gravity, IBUs, SRMs, efficiencies etc.

To achieve this you will need to perform the following steps:

1. Purchase 18 hectares of greenfield site
2. Get consultants to design a 100 thousand hectolitre brewery
3. After planning permission granted, build the plant
4. Hire brewers, chemists, laboratory technicians, plant engineers, fork lift drivers etc
5. Sign contracts with suppliers of malt, hops, adjuncts....

........

.........

 

[pk.sax]

Just do it.

I remember someone telling me this, dunno who, prolly MHB in a thread on here, but basically, I tested with some iodophor at various stages of mash what was happening and deduced that there was full conversion showing at about the 20ish minute mark. However, what as pointed out was that at such time, there are still starches in the grain slowly dissolving out and also the sugar profile is under attack by enzymes and bing broken down.

If I were you, I'd mash high, recirculate or stir like mad and keep the mash short-ish.