How important is temperature accuracy during mashing?

[zarniwoop]

Ok so this is a bit of a back to basics question but I know the theory and I wanted some experiences from AHB members.

My BIAB setup is a large aluminium pot with a valve which I heat using an over the side element supplemented by the electric stove, it works well and is simple to use and clean. When I mash I wil heat to 2-3C above my target temp then add the grain and stir to break up, at this point it's usually within 0.5C of the target, if it's low I add a bit of heat if not I just put the lid on and wrap in a blanket. I monitor the temp with a probe on a wire and when it drops to <1C below mash temp (all single step mashing here) I add some heat with the element whilst stirring, the only downside is since I'm not a PID controller I often overshoot and end up with the mash going 1-5C to 2C over, I then have to leave the lid off and cool for a bit. Rinse and repeat about every half an hour.

So basically the mash temp is good for the first 30 minutes and it then bounces by say +/- 2C (worst case) for the next 60 minutes. Question is would improving the stability of my mash temp make a big difference?

So far my beers are tasty and all concerned are happy with them, I don't know how they'd go down to someone with a more experienced palate than mine but I'm generally happy.

There are obviously a number of ways to improve this situation and I have the skills to implement them but it's going to be time, effort and money that I don't really want to spend unless I'm going to see a big difference.

So any comments regarding how much this may be affecting my beers and if going to a more controlled system would improve things?


Cheers

Zarniwoop

 

[Ducatiboy stu]

Your first 20-30 mins are the most important as most of the conversion is done in this time.

 

[spryzie]

I just go for the slow ramp up from 50'ish mash in to 60'ish (rest an hour) to 70'ish (rest an hour) continue through to boil (boil and hour).

I have always managed to produce beer this way.

When I had problems I was mashing in my single target of say 67 degrees and resting an hour and trying really hard to maintain that temperature.

Now I don't care. 50, 60, 70, boil. Simple

Of course, I don't make award winning beer.

 

[Jkpentreath]

If u can't taste what your missing? You could put a second layer on insulate around the pot and sit it on a styro box first. Before u go spending money. Because everyone on here can tell u , it s like venturing down the rabbit hole, where to stop, and it's a big step from brew in a bag to something u would get the same results from. Biab can make some real good beers. Seen blokes that line there pot with aluminium insulation, I'm only just starting so take what u want out of that.

 

[Yob]

The only reason to change process is if you are unhappy with the outcomes or simply wish to refine, having a controlled mash temp is the primary reason I went a HERMS type setup
... That and crystal clear runnings (not that it makes a big difference bur is sure is nice)

 

[booargy]

crystal clear

:icon_vomit:
no offence intended to you Yob

 

[contrarian]

I could be wrong but I would imagine most home brew set ups have at least a few degrees variance during the mash.

I know with my BIAB setup that there is and a mates 3V has a decent amount if variation too. A recirculating system will probably get you the closest but for me it is more cost in terms of money and time for the benefit. That may change over time.

My guess would be that the biggest factor in stable mash temp is volume due to the high specific heat capacity of water. Insulation will help a bit, recirculating with temp control will help more but I have no idea whether or not an average punter could pick the difference in a side by side tasting.

 

[manticle]

Saccharification is the result of two types of amylase enzymes. They both have different optimum temperature ranges as well as other, different optimum conditions including pH. It's not really as simple as a single temperature. While both sets have optimum ranges, there is crossover between and both will work, to a point, outside those ranges.
Simply put, temperature is super important in terms of what is happening inside the grain but you fussing over a degree or so drop over the course of the mash is probably not necessary unless your results are not as you would like. I deliberately target both sets to get results I want (body vs attenuation and finish) but it is all about the preferred, finished beer.

Below a certain temp, enzymes either won't work or will be very slow, above and they start denaturing. The higher the temp, the more rapidly they denature.

 

[mje1980]

Exactly, and seriously, 2-3 degrees isn't that much, as long as that 2-3 degrees is still in the temp range of the enzyme you're targeting. So, if you're targeting beta, and you vary between say 60-64, it'll be fine, and for alpha, 66-70, same thing. As manticle says, they work outside those temps as well, just not as optimal.

It's one of the main reasons I've kept my setup so simple. If 1/2c difference over the time of the mash was the difference between beer and vinegar I'd worry, but really If you're within the range, you're good to go.


And if you can notice a difference between a beer mashed at 64 and a beer mashed at 66 I take my hat off to you, you have very highly tuned taste buds. Mine aren't so fancy

 

[Bribie G]

Good point about thermal mass of a larger mash volume, say when doing a full volume mash in an urn. I usually hit desired temperature straight away then lose around one and a half degrees with the urn insulated with sleeping bag and metallized foam sheet.

I was round at a fellow BIABer's last weekend and wondered what lagging he was going to use. He simply up-ended the box the Birko urn had come in and dropped it over the urn. 60 mins later, half a degree lost :blink: :blink: :blink:

So simple, if you think about it, air is the best insulator (other than a giant thermos bottle) so by wrapping my urn in stuff that is admittedly an insulating material, the contact between the urn wall and the material is obviously leaching heat out of the urn, whereas just dropping a box over the top the heat has nowhere to go except for the small amount lost to radiant heat.

I'm thinking of doing a big styrofoam version. Edit and flushing the box with very hot air from swmbo's hair dryer first. Arrghhhh brain be still. :wacko:

Back on topic, as Manticle says most conversion in the first half hour.

 

[manticle]

Actually stu said that but the majority of alpha conversion happens very quickly when optimised with most modern malts. Beta is slower but still an hour is very generous for starch conversion.

 

[Ducatiboy stu]

If you wanted to try something different, then split your grain and mash half low & half high, then mix runnings in kettle..

Bit of stuffing around..but hey....who cares when you have time and beers.

 

[Yob]

If you wanted to try something different, then split your grain and mash half low & half high, then mix runnings in kettle..

Bit of stuffing around..but hey....who cares when you have time and beers.

were going to do this for the Vic Swap Brew Day.. 3 mash tuns, 3 different temperatures

 

[Ducatiboy stu]

were going to do this for the Vic Swap Brew Day.. 3 mash tuns, 3 different temperatures

Nice.

Be interested to see how this comes out.

 

[Bribie G]

I did that with a double batch a long time ago. Turned out very nice (ESB type brew as I recall). I seem to remember that I did one lot at 63 and the other at 71 or something. The idea was to have an easy drinking beer with body. The idea that high mashing gives a sweet beer is an urban myth. Body yes, but dextrins aren't sweet. Try a spoonful of maltodex.

 

[manticle]

I think it's because maltose is sweet so underattenuated beer may be sweet due to unfermented maltose. Dextrins are a group of longer chain sugars with varying but generally low levels of sweetness. A beer with high gravity may be sweet (maltose) if underattenuated but if dextrinous, then it shouldn't be super sweet - just full bodied

 

[zarniwoop]

Thanks that makes me feel a little better.

I've read through Palmer on conversion ranges etc but he tends to be both brief and complex, can anyone recommend some further reading for the beginner on this area?