Explain It To Nick: Mash Thickness

Okay, I see it now.... your 2 gallons (8 quarts) is including both permanent absorption of water in the grains AND losses in the bottom of the mash tun. Looks like the breakdown is about 1.2 gallons permanently soaked and 3.5 quarts not being drained out of the mash tun. Okay, I can help you. Give me a couple more minutes......

 

Okay, here you go.... if you strike with 6 gallons water at 163 F, you'll hit about 145 F desired, then can sparge with 1.6 gallons water at about 207 F to hit about 168 F mashout temp.

Doing this will result in a slight loss of efficiency because you're striking with too much volume and not sparging enough. For maximum efficiency, try instead striking with 5.25 gallons at 164 F at a ratio of 1.8 qt/lb, then sparge with 3.25 gallons at 206 F. You should see an efficiency bump of maybe ~3% from this, ballpark estimate.

 

I understand that. Just pointing out that by simply changing the ratio to 1.8 qt/lb, your efficiency will increase towards 70%-ish.

 

Not exactly. I'm saying that a 50/50 split of first runnings and sparge volumes will maximize efficiency regardless of the ratio, and that you can use science & math to purposefully change the qt/lb ratio to anything you want to maximize efficiency, IF you care about doing that at all. Some people care about efficiency, some don't. The efficiency guru will recognize that there simply is NOT any magic ratio like 1.25 or 2.0 or whatever that is always right for every situation; the best ratio to use varies, and it's based in part on the 50/50 volume thing.

I honestly don't care all that much about efficiency, because a couple percent here & there isn't that big of a deal, and I'm getting 80-90% all the time. But if you're only getting low 60s percent efficiency, that's kind of crummy, to be honest. Aiming for 50/50 split of first running volume and sparge volume would help kick it up a notch. That's really all I'm doing. You might also want to mill your grains a bit more, IF you care about efficiency. Maybe you don't.

Just stuff to think about. Don't be locked into any particular volumes or ratios if efficiency matters to you. But if it doesn't matter, then I don't care either, do whatever you want. You'll make great beer either way honestly.

 

Do you know if there's proven science on this. If you mash at 160, will 8 more degrees really deactivate enzymes or was this done during the mash. I know the hotter water thins the sugars more but i often wonder about the mashout temps.
BTW i always use 2.0 qts/pound or even more if i have to raise the temp.

 

Yes, just send me your email address in a private message.

 

0.035 is not very fine. Try at least 0.030. Only back off if it gets stuck, otherwise don't be afraid to crank down even more.

2 qt/lb might improve efficiency but I doubt it. Crush matters more than anything else. If your crush sucks, your efficiency will suck, regardless of the ratio.

 

There is, but it's so commonly understood that I can't think of a paper on it, offhand. The hotter the temperature, the faster they are denatured. OTOH, if you mash for long enough at 160 (or any temp), they will all denature anyway. (But then you haven't locked in a (non)fermentability.) Basically it's a race between conversion of starches/sugars and denaturing of the enzymes. Normal mash temps favor the former. Mashout temps favor the latter.

I should also have mentioned before that increasing the temperature decreases the viscosity of the wort, so it will flow a little easier, helping to prevent stuck runoffs, and very slightly increasing efficiency. (There are various degrees of "stuck.")

 

So, this is somewhat brewery/process dependent, but the value I use (and BrewCipher's default) is 0.025 gallons of wort loss per ounce of pellet hops. And when you lose wort volume, you need more total water, which means more grains to get the same gravity. This is among the reasons why I highly recommend software. Standalone calculators can be good, but they don't talk to each other. And rules of thumb are great, but they typically are derived under a limited set of circumstances that don't always work under other circumstances.

 

I use the orange igloos. My last mash batch was 12-1/2 lbs with 7-1/4 gals(i added more to raise the temp) and it wasn't at the top.

 

That would also be interesting to learn about since i read some malts only take 15 mins to convert.

 

It's possible to have full conversion (or close to it) in 15 minutes. But full conversion only means that all of the starches have been converted to fermentable and unfermentable sugars and dextrins. Beyond full conversion, the longer the enzymes work, the more fermentable the wort becomes, as longer chains are chopped into shorter chains. If you want to read up on the concepts, read the All Grain chapter at www.howtobrew.com. If you want to see some data, Kai Troester ran some experiments about the impact of various mash factors (including time) and the writeup is on the web. Also, Greg Doss (Wyeast) published a powerpoint brief on similar measurements he did. It's available (or at least used to be) to AHA members on the AHA site.

Ironically, "How to Brew" (at least the old version) more or less encouraged brewers to use iodine to check for full conversion, which really ignores the purpose of manipulating mash conditions to get the wort you want. I know a guy who in his noob days read that, went to the LHBS, and asked for an "iodine test kit" (instead of just going to the drug store to buy iodine). As luck would have it, the LHBS was apparently just as clueless, because they indeed did have "iodine test kits" in stock, i.e. chemical(s) that tested for the presence of iodine itself. Anyway, I don't see the value in doing a test for full conversion, except maybe as part of troubleshooting very low efficiency or something like that.