70 deg mash temp more unfermentable sugars?

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phoenixdigital

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So I fell down a knowledge rabbit hole last weekend and was reading up how enzymes work in the mash tun at different temperatures. The rabbit hole got deeper and led me further into a wide range of topics such as how the human body processes starches (similar). Fun fact did you know your liver has stores of vitamin A (1–2 years' supply), vitamin D (1–4 months' supply) vitamin B12 (1–3 years' supply)... I digress... I will put my findings on mash temps which I posted my brewing mate into a second post.

So with my newfound "knowledge" I decided to mash my ginger beer I was about to make at about 70 deg in order to increase the amount of unfermentable sugars and make a sweeter beer.

However something went completely wrong and I ended up with an OG of 47 and a FG of 8?

Most of our beers finish on FG of 12. What happened here? Why so low? This was the exact opposite result of what I expected.

I did pitch a partially washed fresh yeast cake from another beer on top which was Safale-05

Anyone know why I didn't get these unfermentable sugars mashing at this higher temp?

I didn't taste any infection when I kegged it so I dont think an infection took hold.

Recipe below

Souless Ginja


Recipe Specs
----------------
Batch Size (L): 24.0
Total Grain (kg): 4.800
Total Hops (g): 55.00
Original Gravity (OG): 1.048 (°P): 11.9
Final Gravity (FG): 1.010 (°P): 2.6
Alcohol by Volume (ABV): 4.92 %
Colour (SRM): 7.0 (EBC): 13.8
Bitterness (IBU): 19.8 (Average)
Brewhouse Efficiency (%): 75
Boil Time (Minutes): 60

Grain Bill
----------------
3.500 kg Pilsner (72.92%)
0.500 kg Honey (10.42%)
0.300 kg Munich II (6.25%)
0.300 kg Wheat Malt (6.25%)
0.200 kg Crystal 90 (4.17%)

Hop Bill
----------------
20.0 g B Saaz Pellet (6.8% Alpha) @ 60 Minutes (Boil) (0.8 g/L)
15.0 g B Saaz Pellet (6.8% Alpha) @ 10 Minutes (Boil) (0.6 g/L)
20.0 g Saaz Pellet (3.6% Alpha) @ 0 Minutes (Boil) (0.8 g/L)

Misc Bill
----------------
200.0 g Ginger Root @ 5 Minutes (Boil)
10.0 g Lemon Rind @ 0 Minutes (Boil)
50.0 g Ginger Root @ 0 Days (Primary)
50.0 g Lemon Juice @ 0 Days (Primary)
200g of silced Ginger Root @ 0 Days (in keg)

Single step Infusion at 70°C for 60 Minutes.
Fermented at 18°C with Safale US-05

Recipe Generated with BrewMate
 
Below is what I posted my brewing mate. But based on the experience I had mashing at higher temps this is all wrong?
----------------------------------
Better simple explanation in a video
http://www.dnatube.com/video/639/Amylase

No need to follow any links below just read explanations.


There are two basic forms of sugar Monosaccharides = http://en.wikipedia.org/wiki/Monosaccharides
  1. Dextrose/Glucose = http://en.wikipedia.org/wiki/Glucose
  2. Fructose = http://en.wikipedia.org/wiki/Fructose
Table sugar is a dextrose and a fructose molecule joined

Starch is a whole heap of glucose molecules joined together in a straight line or like a tree = http://en.wikipedia.org/wiki/Starch

The enzymes in our mash are the following (funnily enough our mouth has similar enzymes)

beta amylase = lower temps
alpha amylase = higher temps

They break them down like video above into

1 unit of glucose = Dextrose http://en.wikipedia.org/wiki/Glucose
2 units of glucose = Maltose http://en.wikipedia.org/wiki/Maltose
3 units of glucose = Maltotriose = http://en.wikipedia.org/wiki/Maltotriose
4-10 units of glucose = Oligosaccharide http://en.wikipedia.org/wiki/Oligosaccharide
etc....

Yeast can generally only eat Dextrose, Maltose and Fructose so all the more complex sugars are left behind to give your beer a sweetness.
http://en.wikipedia.org/wiki/Yeast#Nutrition_and_growth

So mashing at higher temps should give you more complex sugars that the yeast can't eat.
 
Do you add honey to your brews that usually finish higher?
Honey can take a FG lower
 
Your understanding of the theory is basically correct - a higher mash should leave a more dextrinous wort, leaving a fuller bodied beer at a higher FG.

This is due to the conditions that favour alpha activity being optimised. However the function of enzymes is influenced by other factors as well - time and pH are two of those. Optimised alpha will convert starches quite quickly.
How convinced are you that your measuring equipment is corrct? Thermometer? Hydrometer?

Next time try a 20-30 min mash at 70.
 
In the natural world there is always a reason!

1. When doughing in did you heat up or cool down to reach mash temp.

2. 10.42% of your fermentables were monosaccharides, fructose and glucose which needed no conversion from starch. Take the fermentable sugars produced during the mash and add the simple sugar adjunct and more than 10.42% of total fermentables were provided by simple sugars, maybe as high as 15% or more. Calculating predicted FG would be very difficult, you could assume a total of 20% fermentables would be totally fermentable with the remainder being variable through the range Maltotriose - Oligosaccharide

As with all thing brewing - What you got, was what you got! However the average attenuation of your fermentation 82% is not uncommon for US-05 in good nick.

Screwy
 
Dan2 said:
Do you add honey to your brews that usually finish higher?
Honey can take a FG lower
Ah yes we normally dont use honey for the 12 FG beers. So that would definitely be one of the reasons. Based on Screwtops post the yeast just would have gobbled the honey right up and left nothing behind.

I knew there would be a benefit to post in the recipe as well.


manticle said:
How convinced are you that your measuring equipment is corrct? Thermometer? Hydrometer?

Next time try a 20-30 min mash at 70.
The equipment hasn't changed since previous brews but yes I am not 100% sure of the accuracy of thermometers. I know that the 4 thermometers I have all show a range of temps + or - 4 deg.
Digital, Analogue and infared thermometers.

Ah yes a shorter mash time might be in order to minimise the work the enzymes can do. Does this run the risk of a starchy beer?

Screwtop said:
1. When doughing in did you heat up or cool down to reach mash temp.

2. 10.42% of your fermentables were monosaccharides, fructose and glucose which needed no conversion from starch. Take the fermentable sugars produced during the mash and add the simple sugar adjunct and more than 10.42% of total fermentables were provided by simple sugars, maybe as high as 15% or more. Calculating predicted FG would be very difficult, you could assume a total of 20% fermentables would be totally fermentable with the remainder being variable through the range Maltotriose - Oligosaccharide

As with all thing brewing - What you got, was what you got! However the average attenuation of your fermentation 82% is not uncommon for US-05 in good nick.
Temperature was about 76 before I put the grain in from recollection.

Yes I see your point about the honey that was probably the cause of the lower gravity.

Thanks for the responses guys glad I am still on the right track. Next time I might try mash towards the higher end of the alpha amylase temperature range and for a shorter period of time. I really want to get a much sweeter ginger beer.
 
No risk of starchy beer in my experience. I mash milds and some bitters at 69-70 for 30 mins to hit 1016 from low FG
 
On further reading about Honey
http://en.wikipedia.org/wiki/Honey#Nutrition

Typical honey analysis:
Reading that it looks like 77.9% will be eaten by yeast. 17.2 % is water leaving 4.9% of the honey remaining in the final beer. Which considering I only used 10% honey in the wort means 0.5% of the final beer is made up of the remnants of honey.

Makes me think honey would be barely noticeable when used in beer.
 
This is exactly the same reasoning I followed when I did this today http://aussiehomebrewer.com/topic/74807-all-grain-ginger-beer/

Basically, trying to find a nice way of adding a little residual sweetness to a ginger beer without using lactose, artificial sweeteners, or postmixing. So, what's the consensus? Despite the higher temps, we may have ended up with a bit of non-optimised beta conversion, hence a more fermentable wort than expected?

My method was a bit different, so I guess I may get different results - for better or for worse.

2Kg Pilsner mashed at ~72 C for 90 mins. Mashout at 80 C.
Added 1.2Kg sugar along with lime zest and juice, cinnamon stick and ginger just before the boil started.
30 min boil, then cubed. Will pitch WLP530 tomorrow, and make a couple of raw ginger additions to the fermenter before it's done.

If I can stop this one getting down to 1.005 like all the others I've done with US-05, I'll be happy. And if that doesn't work, looks like a shorter mash is the go? Anything else we can try?
 
Mashing for 90 will work against what you wish to achieve. Shorten that to 30 mins and you should get the effect you want
 
Thanks, manticle. I wish I'd seen this thread this morning. Would have been enough time to change my plans... only just. I'll just have to see how it goes this time, and adjust for next time. Surely this can't turn out any drier than any of the other gingers I've done.
 
MCHammo said:
Thanks, manticle. I wish I'd seen this thread this morning. Would have been enough time to change my plans... only just. I'll just have to see how it goes this time, and adjust for next time. Surely this can't turn out any drier than any of the other gingers I've done.
Looks like we are both trying to achieve the exact same result here MCHammo. I think if this doesn't work out too well I might start experimenting with smaller 5L batches until I crack it.

I want a sweet super zingy (not too beery) ginger beer.

I was hesitant to add hops but found some recipes which seemed to indicate it was still required. Looks like we both need a much shorter mash time too.

Keep me posted to how yours goes.
 
Yeah, pretty much exactly what I'm aiming for. I don't want mine super sweet (like Swedish ciders, for example), but just a normal (but very zingy) ginger beer that hasn't fermented out to complete dryness.

I still haven't added hops to mine, I never needed to with straight gingers. Ginger is supposed to be a decent antibacterial agent and preservative, so I see it as more of a replacement for hops than an addition. 6 batches of ginger beer to date without infection (and much lower sanitation standards than I now keep).

Will definitely keep you posted. I feel a collaboration coming on.
 
phoenixdigital said:
On further reading about Honey
http://en.wikipedia.org/wiki/Honey#Nutrition

Typical honey analysis:
Reading that it looks like 77.9% will be eaten by yeast. 17.2 % is water leaving 4.9% of the honey remaining in the final beer. Which considering I only used 10% honey in the wort means 0.5% of the final beer is made up of the remnants of honey.

Makes me think honey would be barely noticeable when used in beer.
I think where people get confused about honey being 100% fermentable is that technically its not as per the above description but when calculating a recipe all the gravity points honey brings (which I have in a book as 35 points per 1lb in 1 usgal) will pretty much ferment out given time and as such adjuncts such as honey should not be included when trying to calculate over all mash efficiency.
 
Now this is very interesting. I raised this exact point of mashing at higher temps to achieve a sweeter finish ginger beer in this thread a while back.

Parks replied there that:

"Mashing high doesn't add sweetness as dextrins aren't sweet. You will get maltiness from, well, malt and extra body at those temps."

I did a little experiment and mashed a few kilos of pilsner, some carapils and a bit of munich at 70C for an hour, boiled up with a LOT of ginger (400g in 12L) and no hops, fermented with US-05... the result?

A dry, sour ginger ale, which to my palate was less thin than other hombrewed ginger beers I'd tried. Similarly I added honey to my boil but found no appreciable honey flavour with all that ginger in there. I'll have to look up the FG when I get home but from memory may have been 1.008 as well (FG of 1.046).

I'd love to know for sure whether a higher mash temp does add sweetness - or do the extra points in the FG represent only the extra body? Are the dextrins/eznymes produced with a higher mash temp actually sweet? My experiment would say no. My science isn't up to scratch to comment.
 
From experience, I notice very little if any difference in mouthfeel between a beer of FG 1.014 which was mashed at say 70C and another of the same finishing gravity which was mashed lower at say 66C, when all other things are equal. If dextrinous malts are used to increase mouthfeel AND the mash temp is higher to promote a more dextrinous wort AND a less agressive yeast is used..........then I can notice quite a difference. Things are not so one dimensional in brewing!!

Screwy
 
My understanding is that it is just not as simple as more sugar = more sweet. Fuller mouthfeel will add to a perception of sweetness (or conversely dry finish will be less likely to be perceived as sweet). Also various sugars have different sweetness levels. I don't think it's correct to say dextrins aren't sweet as dextrins covers a range of sugars with varying levels of sweetness - however a dextrinous wort will not necessarily be super sweet.

What Screwy is suggesting is that there is more than one factor at work - so high temp, low time, lower attenuating yeast will all come into play. As has been found - not accounting for all of these has led to a result different than expected.
 
Just to add to the mash temperature discussion:

http://woodlandbrew.blogspot.com.au/2013/01/measured-mash-temperature-effects.html

This bloke did a test on mash temperature and found that final attenuation decreased by approximately 1% for every degree Fahrenheit above 152ºF (66.7ºC), tested up to 160ºF (71.1ºC). According to those findings, for example, if you start with a yeast with 80% attenuation, mashing at 70ºC (158ºF) would result in ~74% attenuation not taking into account any other factors.

Of course mash temperature isn't the only factor in play, but it's something to keep in mind for future brews.
 
A higher mash temp won't result in a sweeter beer. It will increase body and alter mouthfeel. As said above higher weight dextrins are not particularly sweet, buy some pure maltodextrin powder and have a taste. If you want a sweet beer you have to leave some residual sweet sugars in it (by not fully fermenting out), or add an unfermentable sweet ingredient like lactose or artificial sweeteners.
 

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