BeerBorg

I thought I might relate my BIAB experience yesterday for other Newbie AG brewers out there.
Yesterday I mashed a recipe (a Red/Blonde Märzen) including 2 decoctions with primarily Vienna malt and about 27 % other grains that just wouldn't complete conversion in the 1 hour planned for the mash. I extended the rest @ 160 for first 10 min, then 20, then 30 and finally the iodine test proofed after 2 full hours. I was at a loss as to why the extra full hour. The final OG was right on target so I guess I lucked out.

After kicking this around with my local brew shop, they are used to my dumb questions by now, it probably was a PH problem, which we doubted as I used some acid malt, a procedure problem by doughing in @ 58F and missing my target rests, which I assured I hadn't, and lastly, a possible grain bill problem. It seems Vienna malt has barely enough enzymes to convert itself, and with 27 % of the recipe using carared, melanoidin and carafoam (lo to no enzymes), there just wasn't enough enzymatic strenth to do the conversion.

I was getting pretty cocky on my brewing proficiency and this was an eye opener. I will definitely pay more attention to the grain bill in the future. Hope this helps someone not make the same mistake.

Vienna should have a Diastatic power of 120-140 or so. Munich has more like 30-40 or so. Munich can self convert (and I mash Munich all the time), so you only need 30-40 to self convert. So Vienna has way more then enough to self convert and to convert other grains too.

But maybe 27% is too much. But I have done 10-20% with Vienna as my base malt without issues.

How long did you leave your mash at a saccharification rest temp? 160 is pushing the limits there, some of the enzymes are shut down at that temp - that's typically for the 3rd decoction which is more of a mash out, so you are not really doing a lot of conversion at those temps. It's possible you simply would need to extend the saccharification rest (more like 140-150 range) and it would have been done a lot sooner. You should be doing your iodine tests there IMHO, not after you bring it up to mash out temps.

I don't know if this will help u or not, but if u look at this chart, it tells you the recommended max % of each grain, etc. But then again, I could be missing your question totally.

http://www.beersmith.com/Grains/Grains/GrainList.htm

Based on Home Brewer's Companion by Charlie Papazian the Enzymatic value for German Vienna is 95 (72% of grain bill), Carared has none (14.3 %), melanoidin is very low, and carafoam is 33 and acid malt is also very low.
American Vienna has a greater Enzymatic of around 130 or so. I didn't use any Munich.

Per the German recipe I did a 30 min rest @ 145 and a 30 min @ 160 and a mash out for 10 @ 168, sparging @ 170.
I always do the iodine test before mash out.
I'm thinking that the mash just didn't have the enzymatic power to complete sooner. I may be wrong.

Thanks for the chart FrozenInTime... I will bookmark it.

FYI, Briess uses 6-row to make their Munich/Vienna base malts. They use 2-row for their specialty Munich (aromatic/bonelander, etc.) . German Munich/Vienna is made from 2-row. That's why they have different enzymatic power.

Good to know..
Since it was a German recipe I attempted to stick to German grains. I hope to eventually brew some very authentic German lagers and am improving but still have a lot to learn on the process. My German guinea pigs tell me I'm getting close.
My mistake was veering from the original recipe adding low enzymatic malts to up color without considering how it affected the proportions for a good mash.
Also hope I haven't bored everyone to death relating my mistakes, but thought some of the newer brewers like myself not make the same mistakes.
It's bubbling away as I speak and I hit my targets so it can't be all bad.

Texas Dan wrote:Also hope I haven't bored everyone to death relating my mistakes, but thought some of the newer brewers like myself not make the same mistakes.

Not at all. I'm sure the wealth of knowledge people have gained through me posting my mistakes has been HUGE. And I haven't bored anyone to death......Hello, hello...is this mic on.

Texas Dan wrote:It's bubbling away as I speak and I hit my targets so it can't be all bad.

See, in the end it WILL be beer.

After starting out with Mr. Beer a little over a year and a half ago... I have learned invaluable knowledge on brewing great beer from all of you experienced brewers... I know we don't say it enough, but this board wouldn't be as successful without you..
Thanks.