I am interested in compiling a list of different step mash profiles. I would like to include an indication of the potential fermentability the mash leads to and the expected benefits of any odd steps (e.g. a ferulic acid rest at 110 to develope clove aroma in a hefe).
I think everyone is clear that, all else equal, a single infustion at 149 will yield a more fermentable wort then 155. But how would these two compare to a Hochkurz mash (picked this one up from Kai) with a 35 minute Maltose rest at 145 and a 45 minute dextrinization rest at 160. When I look at this profile I have no idea what the fermentability will be like. Would this step mash yield fermentatbility more towards the 155 end of single infusion or the 149… Is there any rule of thumb you guys use?
(obviosly I am comfortable with single infusion mash results so I think about this in terms of the single infusion fermentibility being the scale that I am trying to fit step mashes to.)
James, I don’t think you’ll be able to make that conversion table. Because I had the same questions I have looked into mashing and how it works quite extensively. I have to tell you that there are too many factors involved which makes developing a prediction model for mashing difficult. Mash pH on the other hand tends to be much more predictable.
What you need is a history of past brews that you can rely on to get to your targeted wort fermentability. Once I was there I became more consistent with getting what I wanted from the mash.
What I do is to test the wort fermentability with a fast ferment test for every batch. This cuts out the effects of fermentation and I get a number for the actual fermentability of the wort. When I then plan a new beer I would look though my notes on similar grists with similar mashing profiles to see how long of a maltose rest, for example, I want to hold.
Recently I brewed a single infusion vs. Hochkurz experiment where the single infusion was done first. Once I had the fermentability of that wort I also had an idea about the length of the maltose rest in the Hochkurz mash by using past data. With the 2nd beer I was able to get within 1% of the fermentability of the first beer.
I can only make qualitative statements when it comes to the effects of mash conditions on the fermentability:
Any lower temp rests will give you better fermentability. This includes ferulic acid rests and protein rests.
more highly kilned malts will lower fermentability but that doesn’t go linear with color.
decoctions tend to give better fermentability at the same sacc rest temp than a single infusion mash. This is because there has been a lower temp rest and b/c the decoction will add a lot of gelatinized and dextrinized (I’m not sure if this is actually a wort) starch to the mash which provides much more substrate to the b-amylase while it is still active. Decoctions also lower the enzymatic strength with counteracts this effect a little.
pH also affects attenuation. But for our discussion we can assume that it remains constant.
However, It has been my experience that a wort fermentability difference of a few % is pretty much undetectable as long as the attenuation to attenuation limit difference of the beers is about the same. This is why I don’t worry if I target a fermentability of 82% and get only 80%.
all good points, but in speaking in a broad and generalized manner, I am sure that some people on this forum have certain step mash profiles that they use to achieve certain desired results. I’d still be interested to hear some of these examples.
(This is about the time when Denny steps in to tell me there really is no difference, it’s all a waste of time :P)
What I have done is graph the results of my brewing. If you have enough data points, especially the same yeast and similar beers, and you are consistent in your process, you should be able to see the relationship between mash profile and attenuation ON YOUR SYSTEM. At least enough for you to be able to predict FG.
The consistent includes on a single system and assumes very little changes. As Kai said, there are too many factors to be able to calculate.
I’ve used a version of Kai’s documented Hochkurz method for a few brews. I’d say that the Fermentability and Mash Efficiency are improved. I haven’t done side-by-side tests but know in comparison to other single infusion brews the numbers are better. Accident? Maybe, but I tend to think the modified double decoction makes a difference. If for nothing else to justify my time & effort. ;). For example. A recent Weissbier produced 90.4% BHE and the WPL380 took it from 1.052 to 1.008, ~85% Apparent Attenuation. I generally run in the ~82% BHE range for ~1.050 beers and the AA varies with the yeast.
Just last weekend I did a Doppelbock/Bock Partigyle utilizing a modified double decoction. Both are fermenting right now with slurries of 34/70. I don’t have the AA yet obviously but the BHE for the batch was ~85% which is way over what I expected for 33 lbs. of grains & 10 gallons of beer where the Doppelbock OG was 1.100 & the Bock OG was 1.076 after blending the worts.
It’s not scientific by any means but in comparison with similar brews, the modified double decoctions have been more efficient, and tasty I might add. The results have had their rewards. A Weissbier was Honorable Mention at the 2010 NHC Finals and a Strong Scotch Ale won BOS at the Nebraska State Fair and BOS runner up at our County Fair. Coincidence? Maybe, but I plan to continue to invest the time & effort into the brews that lend themselves to decoction mashes. Cheers!!!
I had to look up Hochkurz method, I had not heard of it before. I’ll frequently do a decoction on my big beers looking for a 146-148 to a 153-154, trying to maximize the attenuation of the beer. I have not done a side by side but I felt that I got a few points out of it. A few points on a 15% beer can make a noticeable difference
Yes, because it is a more intensive mashing schedule, a decoction mash has the potential to be more efficient than a single infusion mash. How much more efficient depends mainly on how inefficient the single infusion mash was.
I saw this old thread after seeking out some mash profiles. I add this so I can find it.
ORVAL
Mash schedule
142°F (61°C) for 15 minutes
154°F (68°C) for 25 minutes
162°F (72°C) for 30 minutes
and 170°F (77°C) for 10 minutes before sparging at 170°F (77°C)
IBUs: 38
Carbonation: 5.0 volumes
CHOUFFE HOUBLON DOBBELEN IPA TRIPEL
Mash schedule
127°F (53°C) for 20 minutes
145°F (63°C) for 20 minutes
154°F (68°C) for 10 minutes
and ramp to 176°F (80°C) for sparging
IBUs: 53
Carbonation: 4.3 volumes
SAISON DUPONT
Mash schedule
113°F (45°C) mash-in, gradually raised to 162°F (72°C) over more than 90 minutes
