Dispelling Myths? (fwh, Step Mashing & Aeration)

[WildaYeast]

Hi All,

Was doing a bit of browsing on the BeerTools site, contemplating purchase of BeerTools pro. Came across the above article. I don't think it has been discussed here yet -- it appears to have been posted about a month ago.

I won't quote the article, you can read it youself (link below). In summary, he suggests three views that run counter to 'proven wisdom':

1) Don't first wort hop -- First addition no sooner than after 10 mins vigorous boil

2) Step mashing -- For todays highly modified malts, a 20 min mash is probably sufficient (and less is more)

3) Don't aerate your wort -- OK for yeast starters, but go easy

I found it an interesting read and thought it was worth a post. Might generate some interesting discussion...

Cheers, Brian

http://www.beertools.com/html/articles.php?view=245

 

[Ash in Perth]

1) I dunno

2) not really, B-amylase (creates maltose) is completely gone after about 30min at 66DegC, a-amylase(randomly splits sugar molecules) lasts up to 90min at 70DegC. if you jsut want a fermentable wort then most of this will come from a 30min mash, but a higher efficiency and greater body and probably malt flavour would come with longer mashing.

3) Dont aerate if: you want a long lag time to generate different esters. Other than that aeration helps the yeast get going and ensures a good ferment, aswell as having effects on flavour.

 

[peas_and_corn]

I agree with Ash, especially on the aeration part. For my first few Ag's, I wasn't aerating properly- for my most recent one, I aerated it a lot, and it went off like a rocket, and has had some great attenuation because of it!

 

[berapnopod]

3) Don't aerate your wort -- OK for yeast starters, but go easy

This article was discussed at length a while ago on HBD. See this post and later ones for detail

My personal observations:

1. FWH does give a significant difference, but in my experiment it was not worth the effort and depended on how old the beer was as to which one I preferred.

2. Possible, but I am still too chicken to test it out - 20 min mash that is. I have noticed with some wheat beers show a significant difference in an iodine test between the 60 and 90 minute marks.

3. I think this one comes about from a big brewery perspective and doesn't necessarily apply on a homebrew scale. It requires that you make a big enough starter so that there is no need for the yeast to multiply. All they do is ferment. Then the oxygen requirements are much lower, so less oxygen = less oxidation.

But the amount of yeast you would have to make for a starter means its probably not worthwhile for the homebrewer, unless you're repitching onto a fresh yeast cake. But then you ahve to make sure you're wort that made the yeast cake was around 1.030 etc etc etc blah blah blah.

Berp.

 

[andrewg]

Here's my 2cents worth:
1) my results with FWH have been variable
2) could be true, but a 90min mash & no iodine test is my SOP
3) this might be true if you are using a fresh yeast cake, but in most home brewing situations the tendency is to under pitch so aeration is essential IMHO

 

[user 384]

1) Don't first wort hop -- First addition no sooner than after 10 mins vigorous boil

My personal view is that I get more consistent results following traditional schedules and not FWH. I agree with the assertion of the article that you can achieve smooth bittering, the purpose for FWH, simply through hop selection. Low alpha nobles have proven over a long period of time to provide very fine bittering.

2) Step mashing -- For todays highly modified malts, a 20 min mash is probably sufficient (and less is more)
His comments are perfectly valid, IF you are using commercially specified malts designed for high adjunct brewing. The suggestion to use a quick, 20 min, and hot, 68C-70C, mash would be fine if you were using a high % of adjuncts like rice or kettle sugars. However this would result in a less than desireable wort for our purposes of craft brewing that usually avoid high % of adjuncts. It is likely to produce a very dextrinous wort with poor fermentability, hence the need for adjuncts. The stated reason for such a mashing schedule is that it reduces contact time with the husks that can lead to the extraction of tannins (astringency) and lipids (poor head retention). If you are not experiencing such problems, then I don't see the advantages in this approach. It's been said a lot of times before, that starch conversion is not the end of the process, producing a wort with the right balance of fermentable and unfermentable sugars is the goal. After, 20 mins you might have starch conversion, but I doubt you will have the balance required for the majority of beers.

3) Don't aerate your wort -- OK for yeast starters, but go easy

This is based on the idea that it's yeast that need oxygen, not your wort and that oxygen is detremential to your wort as it can lead to staling and reduced stability. If you pre-load the yeast with plenty of oxygen, they will be able to perform perfectly well in fermenting your wort and at the end of the fermentation, when it no longer matters, they will have used up all their reserves. For HBers it's easier and more consistent to add oxygen to the wort for the yeast to use. Aerating your wort is not ideal, but it is a practical approach for HBers. If you haven't had any problems with the staling effects of oxygen, then there is no reason to change your practices and even if you had, then I would suggest you look at other factors first.

This guy has learnt some new approaches that commercial brewers are relying on to make small % gains in quality. They are not neccessarily applicable on our small scales, and there are probably other areas of improvement for us that will make significant changes to the quality of our beer, before we worry about these fine tuning approaches.

Cheers
MAH

 

[neonmeate]

one thing that nobody has discussed here - this guy claims that blind tastings with dextrin powder stirred into beer revealed that body is not related to dextrin content - hence (he argues) there is no need for adjusting mash temps at ALL.
i must say i think this is a heap of crap. i can tell underattenuated beer from overattenuated beer pretty easily.

on the other hand: i agree that FWH is a waste of time - he presents very good reasons for this: the "smoother bitterness" is only cause the FWH hops get caught in the hot break and are muted by the protein gunk).
i get more predictable and consistent hop flavour from kettle additions.

aeration: makes better beer. but isn't always necessary.

 

[Stuster]

I don't think that the difference in FWHing effects is just due to loss of hops with the protein gunk. George Fix's original article, here, did analysis on the IBU levels and analysis of the aroma characteristics through lab tests and the results showed differences in the make up of the aroma compared to 'normal' hopping.

I don't think he is saying there is no point in changing mash temps. He is arguing against step mashes to create dextrins. Apparently, lab tests show that dextrins are not responsible for mouthfeel, against the current orthodoxy. He just says that something else must be going on to cause the mouthfeel difference, even though we don't know what it it yet.

Ditto to MAH's explanation of the aeration comment. I think there was a poll and several AHB members said they only aerated their starters. As long as the yeast count is adequate, there should be no negatives from this, but if you are pitching less than optimal starters, the beer will suffer.

 

[neonmeate]

I don't think he is saying there is no point in changing mash temps. He is arguing against step mashes to create dextrins. Apparently, lab tests show that dextrins are not responsible for mouthfeel, against the current orthodoxy. He just says that something else must be going on to cause the mouthfeel difference, even though we don't know what it it yet.

Exactly, he is arguing against adjusting the dextrin content of the wort with mash schedules, cause [he says] it makes no difference to the body of the beer [presumably he never uses carapils either then]. right?
from my experience i don't think this is true.

 

[DJR]

I don't agree with his main problem with FWH, which is that it affects head retention. One of the best head retentions i had was from an FWH beer. But then again, i haven't honestly noticed much difference in hop "sharpness" between using FWH and a good 60m addition into a rolling boil with some low co-humulone hops. I think it helps for hoppy styles (ESBs/IPAs/APAs), but for the German beers he's talking about, there's probably not much point, plus the economics (since you would have to use more when FWHing) probably cancel the benefits out.

As for 20 minute mashes, 6-row does have more DP than 2-row, and it seems he is referring to the US malt varieties that could probably convert a house brick to maltose if you wanted it to. I've done a couple of 45 minute mashes and the difference was not much. 2-row malts we get here will still convert quickly - the lab-quoted Sacc time on most well-modified malts is given as 10-20 minutes, mashing longer would be necessary for highly attenuated styles such as dry lagers and Kolsch-style ales.

I'm not going to offer any guidance on dextrin profiles, all i will say is, that if maltodextrin is flavourless and makes a beer "slimy", then what is the difference between that and dextrins created in the mash. Most of a beer's body seems to come from residual sugars, proteins and long chain sugars, i'd be surprised if dextrins really create that much difference.

 

[MHB]

There is a rule in brewing that we can never forget:-

Everything you do affects the taste of the beer.

1/ he might be right about this one, I personally dont see the point. Longer boils and better hop choices can I thing give better outcomes, (but if it works for you - go for it!).

2/ jump mashing (an extreme version of step mashing) is a valid way to make low alcohol - high body beers.
At 20 minutes a very finely milled grist will be (nearly) all converted, there will be some residual starch, the coarser the grist the higher the chance of some getting into your finished product (starch haze).

3/ aeration of the wort is a well researched science, you can over do it, and under do it to. Every decent sized brewery uses dissolved Oxygen meters (DOM) to measure O2 at every stage in the brewing cycle, including in the wort.
The same applies to yeast, there is a right amount and all the other amounts, over and under pitching can both cause problems.
What the yeast eats as it is reproducing is important to the final product and plays a significant roll in head stability.

Shorter mashes are obviously a place to save time, and for breweries, money. 50 years ago Ale breweries routinely mashed for 90-120 minutes, and boiled for 2 - 4 hours, a 400 minute brewhouse cycle was a common target (mash in to cast wort ~6 1/2 hours).

A modern high speed brewery with mash-filters can bang out up to 14 worts a day (1 3/4 hours) some even faster, but do you want to drink their beer?

MHB

 

[DJR]

On the subject of 20 minute mashes, i also found this page

http://www.draymans.com/articles/arts/14.html

Interesting article that covers alot of ground, also dispels the decoction myth. No-sparge brewing seems to be the way to get better malt profiles along with addition of malts with high MRP (maillaird reaction products) eg. Vienna/Munich/Melanoidin. Perhaps this is due to the different action of mash enzymes in a thinner mash.

I remember reading about Kurz/Hoch somewhere but can't remember where, maybe it was Promash or something.