This is a great thread. I did 5 AG batches in the past 2 weeks, and got about 40% efficiency on all of them. I think I’m beginning to figure out why. (I ended up supplimenting with LME or collecting only 3 gallons of wort to end up in the right gravity range.)
just curious what your ideal mash ratio is for higher gravity beers. i’m doing Denny’s RIPA this weekend and for equal runnings it’s about 1.3 qt/lb on my system in this weather. i was thinking about doing 1.5ish qt/lb and having slightly unequal runnings.[/quote]
I also prefer thinner mashes, for the same reasons Shadetree does. But I don’t typically try to set my ratio for anything other than to get roughly equal runnings. I will mash as low as 1.25 qt/lb, and as high as 2.25 qt/lb. Depends on the OG for the beer I’m brewing. With a typical efficiency of 80%, I’ll usually end up with around 2 qt/lb for an average strength beer.
Revisiting this about 4 months later, I wish I had better news to share. I suppose I’ve learned alot, but my brewhouse efficiencies are still in the 65-70% range, with 67% being the most common & frequent.
Improvements & things tried:
- I've checked & refined my mill gap spacing with a feeler gauge. Now at 0.028 to 0.030", and crushing conditioned malt (0.25 oz water/lb).
Collecting (sparging / draining) mash run-off in two equal volumes, making sure the mash tun is as drained as possible.
Using at least 50% RO water, sometimes more (mostly to cut my high-bicarb water down to normal, and to reach desirable pH with only 2-3 grams of gypsum or CaCl additions).
Brewed Today: NB’s Belgian Dubbel recipe
, +1 pound base malt. Mashed at 1.5 qt/lb. pH at 5.25 (confirmed by calibrated meter; at 111 F, though meter has ATC). Temperature 153-154 during 75 minute mash (using thermapen). After first runnings+sparge was 1.064 OG (converted from RO-calibrated Refractometer). Preboil OG was 1.047; preboil volume was 7.1 gal…
I still suspect there are nuances to the batch sparge I’m missing. Suppose I need to add 0.5 gal before the first sparge, and then another 4’ish gallons for the second sparge (like I did to for the dubbel). Should I ensure the sparge water is close to boiling temperatur, or is 180-190 ok? Should I stir it like a madman, and if so for how long? Should I wait 5-10 minutes after adding the sparge water before draining?
I think I’ve eliminated most or all equipment-related measuring errors (though I suppose my refractometer could be off at the higher-end, but I’m not sure how to check it). However, on the topic of equipment, I suspect that there may be a relationship between grain bed surface area and efficiency, such that if I had 12 pounds of grain mashing in a cylindrical 10 gallon cooler (as I am doing), that I may see lower efficiency than if I had that same 12 pounds of grain mashing in a rectangular, 20 gallon cooler. This could also be interpreted as an inverse relationship between grain depth and efficiency. Any thoughts?
[quote=“Silentknyght”] Mashed at 1.5 qt/lb. pH at 5.25 (confirmed by calibrated meter; at 111 F, though meter has ATC). [/quote]Only thing that jumps out at me, but I’ve been drinking for a couple of hours… ATC means that it reads the pH correctly at an elevated temp, so if you’re at 5.25 at 111F, you’re probably 5.0-5.1 at mash temp. I’ve read that low pH can negatively impact the mash.
Edit: And after looking at my spreadsheet, I see a couple of batches where I noted low pH (5.0 - 5.1) and a resulting lower than expected efficiency.
Hmm. That’d mean I’ve been consistently mashing with low to depressingly-low pH… at least that’d explain the consistently low efficiencies. I’m shooting for a room-temp (68 deg F) mash pH target of… 5.4? 5.5?
I’ll have to take a closer look at the Bru’n’water spreadsheet, too, as–if this is true–its calculated additions are apparently making my pH too low… or my water profile has changed. Bleh.
[quote=“Silentknyght”]I’m shooting for a room-temp (68 deg F) mash pH target of… 5.4? 5.5?[/quote]5.5 - 5.8 is the range at room temp. The pH that bru’nwater is calculating is for room-temp and it’s spot-on every time for me.
You are measuring your gravity after the boil (and cooling), right?
I’d also ditch the refractometer (for now) and use a hydrometer instead. You should also check your hydrometer at 60F in distilled water. I have two hydrometers and both are a little off in the opposite direction.
One thing I have taken to doing is taking volume and gravity measurements after my first runoff. This will tell you if you have problems with conversion efficency. Kai has a batch sparge calculator that is very helpful for this. I consistently get 47+% brewhouse eff. with just my first runoff. The sparge puts me around 70-72% total, and that’s with a concentrated boil (4.5g for a 5.5g batch)
This is a good point: while you are trying to figure out what is going on, take as much data as you can in the hopes that something will jump out at you. When I was working on my efficiency (in an effort to make it consistent, not nessasarily to make it higher), I took exact gravity and volume measurements after each sparge. That allowed me to calculate that for a two sparge mash, 76% of the sugar I got out came in the first sparge. Very useful info for later when I was planning how to seperate runnings for different beers.
Hmm. Well, I’ll try to shoot for 5.6 at 68 deg F, then, but you’ll have to tell me where you found those numbers. Nothing I’ve read suggests a target pH that high…
[quote=“BcuzI’minUT”]You are measuring your gravity after the boil (and cooling), right?
I’d also ditch the refractometer (for now) and use a hydrometer instead. You should also check your hydrometer at 60F in distilled water. I have two hydrometers and both are a little off in the opposite direction.[/quote]
Yes, measuring OG after chilling, before pitching yeast. Why ditch the refractometer? Just superstition? It’s easier to use than my hydrometers.
I’m starting to do this, now. I’ll process the data in a couple days and see what it says.
So, I’m hearing that pH may (still) be a concern, but otherwise perhaps my other speculations on batch sparging may be less relevant.
[quote=“Silentknyght”][quote=“Shadetree”]5.5 - 5.8 is the range at room temp. The pH that bru’nwater is calculating is for room-temp and it’s spot-on every time for me.[/quote]Hmm. Well, I’ll try to shoot for 5.6 at 68 deg F, then, but you’ll have to tell me where you found those numbers. Nothing I’ve read suggests a target pH that high.[/quote]These are the textbook room-temp pH values - at mash temp, you’d be at 5.2 - 5.5 (0.3 pH lower at higher temp). Look at the comment in cell G27 on page 4 of bru’nwater for a reference (the quoted value is 5.3-5.5 optimum at mash temp).
I don’t interpret that comment as you do; do you have the 1981 version of Malting and Brewing Science? I have assumed that sentence is a supporting reference for the 5.2 to 5.8 range he cites, especially since that second sentence doesn’t explicitly state “at room temperature” or “at mash temperature.”
Anyhow, given a 5.2 to 5.8 range cited in Bru’n’water, why would you recommend 5.5 to 5.8? Is that what your experience has shown?
I was just reading Kai’s mash pH info (http://braukaiser.com/blog/blog/2011/03 … mperature/) where he suggests a room temp pH of 5.3 to 5.5 for light styles, or a room temp pH of 5.4 to 5.6 for dark styles. If I had a pH of 5.25 at 111F, that would be (by my estimation) a pH around 5.4 at room temp. That would suggest that pH is not an issue in my mashing/batch sparging efficiency.
I guess i’m back to being stumped.
[quote=“Silentknyght”]I don’t interpret that comment as you do; do you have the 1981 version of Malting and Brewing Science? I have assumed that sentence is a supporting reference for the 5.2 to 5.8 range he cites, especially since that second sentence doesn’t explicitly state “at room temperature” or “at mash temperature.”[/quote]Here’s the comment from the cell: “The acceptable pH range is 5.2 to 5.8 when measured at room temperature. The optimum mash pH range is reportedly 5.3 to 5.5 (Malting and Brewing Science, 1981).” The second part says “mash pH” so I assume that means at mash temp, thus the optimum room-temp pH is 5.6-5.8. Kai’s pH info leans towards the lower end of the range, but IME, pH lower than 5.1 reduces the efficiency (and this would only happen to me when making a darker beer, so perhaps Kai’s suggestion for lower pH with lighter beers works but I haven’t done it myself). As further anecdotal evidence, I’ve worked with two pro brewers recently who both wanted a mash pH of 5.4 and wort at 5.2 going into the fermenter.
Really though, the info you posted was solid and the only thing that I could find that might be a problem was the pH. Try shooting a little higher next time and see if it helps, but I wouldn’t bet money on it fixing anything, just would be good to check it out.
[quote=“Shadetree”]
Really though, the info you posted was solid and the only thing that I could find that might be a problem was the pH. Try shooting a little higher next time and see if it helps, but I wouldn’t bet money on it fixing anything, just would be good to check it out.[/quote]
Thanks for your thoughts, Shadetree. I will definitely try for a pH 0.2 units higher next time. I’ve also been gathering data to plug into Kai’s spreadsheet to analyze where I may be losing efficiency. The values suggest I’m not converting all the sugars I could be–maybe off by 15%–so it’s the best guess I’ve got.
Thanks, again.
Kai states repeatedly on his site that pH values in literature and on his site are, in general, measured at room temperature. Otherwise you also need a temperature reference for the pH quoted to be meaningful. In the scientific and academic world, pH measurements are always done at room temp (with a few rare explicit situations). I’ll point to his conclusion in the ‘how pH effects brewing’ article:
[quote=“http://braukaiser.com/wiki/index.php?title=How_pH_affects_brewing#conclusion”]Mash pH numbers are given for room temperature (20-25 C/ 70-80 F) mash samples
Any mash pH between 5.3 and 5.8 should be sufficient for most mashes
A mash pH between 5.2 and 5.5 is well suited for infusion mashes with enzymatic strong malts
A mash pH above 5.4 should be used for decoction mashes and/or enzymatic weak mashes (i.e. large amounts of Munich malt or adjuncts)
[/quote]
So, basically, sticking a colorpHast strip in my mash was meaningless. Awesome! 
Next time I do all grain, I’ll cool a sample, test it, then adjust based on that reading, pull another sample, repeat. Once I get it in range, can I test that mash’s pH at mash temps and rely on that going forward (i.e., so I don’t have to cool a sample to know if I’m in range)?
Are you measuring the mash gravity? This is the single best indicator of problems in the mash, you should be able to get close to 100% of the lab value with a mill gap of .028" (I do consistently with a .025" gap). After conversion, all your losses are purely due to volume and dead space.
[quote=“nyakavt”]Kai states repeatedly on his site that pH values in literature and on his site are, in general, measured at room temperature.[/quote]Thanks for pointing this out - even that simple two-sentence quote from bru’nwater is easy to misinterpret since he says “room temp” in the first part and not in the second. But assuming that all pH readings are at room temp unless otherwise stated makes sense given that most brewers are cooling the wort. I realize now that it’s likely that the brewers were talking about room temp readings as well and I just did the conversion in my head because I think in terms of mash-temp pH since up until recently I measured in the MT.
Hilariously, the colorpHast litmus reaction changes in such a way to counteract the natural decrease in mash pH at elevated temperatures. So with the colorpHast strips, they seem to read the same at room temp and mash temp, and will always provide the ‘room temp’ mash pH (if you remember to account for the 0.3 offset).
Great to hear! I did remember to account for the .3 offset.
