Maris Otter

[chickypad]

This confuses me. Everything I have read is that MO has a DP of 120. That is pretty high. How can your higher than expected FG be caused by low DP? The enzymes convert starches to sugars, if there are not enough enzymes then your OG would be low, not a high FG. Are you saying that a lack of enzymes causes less fermentable sugars to be produced?

I suspect that is in WK units, which would be a DP of about 40 L.
Crisp is listed at 50 L.
I happen to like single malt APA's with MO, as I think it is a great base for highlighting American hops without being sweet. I haven't had issues with attenuation. Last one I did was one of my house beers (Simarillo Otter - single malt/2 hop), it was 1.057 to 1.010 mashed at 151 and fermented with 1056. This was with Crisp MO.

 

[Qhrumphf]

While there's some process variation and some variation between cultivars for sure, the more kilning and higher color, the more enzymes are destroyed, at least amongst the same species of grain. It would be very unusual to have a highly (relative) kilned base malt like Maris Otter be more enzymatic than lesser-kilned 2-row or pilsner. Wheat and 6 row are a different story since they're fundamentally different plants, but the heirarchy I usually see in terms of DP is 6 row>wheat/pilsner (depends on maltster)>2 row>pale ale malt/Maris Otter>Mild Malt>Vienna>Munich>Amber/Aromatic/Brown/Biscuit/Victory/etc (the last grouping all maybe possibly but not always having a shred of diastatic power but nowhere near enough to convert anything).

50-60 Lintner is what I'm used to seeing with Maris Otter. As in, enough to self convert and to convert a small bit of adjunct grain, but in a heavy adjunct grain bill it's definitely going to need help. Only when I get to Vienna and Munich would I be worried about them not properly converting any other grains without help (although able to self-convert), and with that last group I just assume them to be non-diastatic and needs a proper base malt.

 

[NatureOfTheYeast]

Oops, sorry to cause some confusion. Let me clarify a thing or 2 about my post.

The diastatic power measurement I'm using comes from the batch code on the bags at the LHBS. Below I've listed the 2-Row and MO malts that I use and the only 2 sets of numbers I have immediate access to right this moment. These measurements will certainly differ from maltster to maltster.

Crisp Maris Otter
Rahr Standard 2-Row

Qhrumphf covered DP of grains above very well, and summed up with an excellent hierarchy that's really good to keep on hand or in mind when developing recipes. Sure, MO and Munich, Vienna, etc will self convert without issue. The problem is when you start putting other grains into the mix, especially when you're used to developing a recipe that uses 2-Row as the base. Low adjunct/crystal/roast malt beers won't suffer as greatly when subbing MO directly for Standard 2-Row, and some won't suffer at all.

Another thing is that the amount of enzymes is not in relative proportion to the type of enzymes. Some malts have higher Alpha Amylase, some have more Beta Amylase, and this will affect the OG and FG respectively. In response to laredo7mm's question, yes MO will have a slightly higher amount of unfermentables due to the nature of its kilning. Another thing to consider is that Beta Amylase, which creates the shorter chain and highly fermentable sugars, is denatured at a lower temperature. That means that either the higher kilning temperature or longer length of kilning of MO depletes the Beta Amylase at a higher rate than the lower temp/time kilning of 2-Row. It also follows that the longer kilning time/higher temp will denature more enzymes overall. There are also crop year and varietal-specific amounts of each enzyme that are unique to each strain, farm, maltster, etc.

Hope that cleared things up!

 

[Qhrumphf]

With most barley specialty malts, there's little to no starch left to convert. Any of your crystal malts or roasted malts have already either had their starches converted into something else or essentially destroyed. With these, I don't worry too much about the influence of base malt, as the only thing the enzymatic action might do is increase yield slightly (I don't recall the chemistry off the top of my head and don't care to look it up at this hour, but I'm assuming enzymes breaking down some of the grain matrix making sugars more accessible). It's the starchy specialty malts (basically those in that last grouping) that will need a little enzymatic help, but those seldom make up a significant portion of the grain bill as their primary purpose is character, not fermentable extract. The issue is using starchy adjunct grains like corn, which IS added for fermentable extract (and the use of flaked maize is certainly not out of place in English brewing where MO would be used). Many of my English ales will use Maris Otter as a base, a bit of specialty grains, and something like flaked oats, flaked barley, or flaked wheat, and I never have issue achieving full conversion (98-99% conversion efficiency without exception). I've never tried using 60% Maris Otter and 40% flaked maize though. And that is where you're going to run into an issue. The beers where I HAVE used that much corn I'm usually 40% Pils malt, 20% 6 row, and 40% flaked maize, and that provides the enzymatic oomph necessary.

 

[Qhrumphf]

Another thing is that the amount of enzymes is not in relative proportion to the type of enzymes. Some malts have higher Alpha Amylase, some have more Beta Amylase, and this will affect the OG and FG respectively. In response to laredo7mm's question, yes MO will have a slightly higher amount of unfermentables due to the nature of its kilning. Another thing to consider is that Beta Amylase, which creates the shorter chain and highly fermentable sugars, is denatured at a lower temperature. That means that either the higher kilning temperature or longer length of kilning of MO depletes the Beta Amylase at a higher rate than the lower temp/time kilning of 2-Row. It also follows that the longer kilning time/higher temp will denature more enzymes overall. There are also crop year and varietal-specific amounts of each enzyme that are unique to each strain, farm, maltster, etc.

Hope that cleared things up!

While this is a valid point, it doesn't inherently impact OG and FG. It simply means that modification to the mash process may be needed. At the same mash temperature, Maris Otter may produce a slightly less fermentable wort than a standard American 2 row, as well as slightly lower yield. The yield though I'd say has more to do with modification of the grain than the enzymes (although they're related). But as you said, Maris Otter may have a slightly lower relative portion of B amylase as opposed to the 2 row, and as such may have it denature more quickly. But adjusting the mash temp to accommodate might yield the same result.

Unfortunately I'm not aware of any maltsers that specifically list the breakdown.

I'd say at the end of the day it comes down to knowing your grains in the real world and how they'll behave.

For anyone who attended NHC this year, a gent from Briess gave a great talk on sensory evaluation of wort. But the real gem in there was a (slightly less effective and consistent than a lab) home process for conducting a congress mash. I plan on playing with the technique extensively in the future. If you want to know everything about how a grain is going to behave, that's how you're going to learn it.

 

[NatureOfTheYeast]

While this is a valid point, it doesn't inherently impact OG and FG. It simply means that modification to the mash process may be needed. At the same mash temperature, Maris Otter may produce a slightly less fermentable wort than a standard American 2 row, as well as slightly lower yield. The yield though I'd say has more to do with modification of the grain than the enzymes (although they're related). But as you said, Maris Otter may have a slightly lower relative portion of B amylase as opposed to the 2 row, and as such may have it denature more quickly. But adjusting the mash temp to accommodate might yield the same result.

Oh, great point! I forgot to mention that mash temperature can also play a role at maximizing your B amylase activity, and I also forgot about modification. Let's also not open the huge can of worms that is mash pH, too!

Just goes to show that malt is perhaps the most complex brewing ingredient, and so much consideration goes into determining its use. No one has all the answers, and it's on the brewer's shoulders to research as much as possible in order to understand the nuances and subtleties.