Mash Temperature guesstimation

[Hoont]

I'm guessing this mash temperature is the root of my thin body problems. I mostly make session beers starting out at 1.039 to 1.046. The problem is they are finishing out at 1.006 to 1.009. I can't seem to keep much residual sugar. I attempt to mash high 154 to 156 but with the wild swinging temperatures, I may have cold spots that keep drying out my beers. I do some step mashes but typically I'm single infusion, batch sparge. I mash in a kettle on the stove top so I can add heat (by the way, I never seem to scorch; there is about a gallon of water under the false bottom).

So what if mash temp is not my thin body problems... what else would cause me to finish out really low consistently? I typically use wyeast american ale and london ale yeasts. I just made the mexican logger with White Labs Mexican Lager and that finished out at 1.006 as well. I did verify my hydrometer, refractometer and thermometer are calibrated. Just want to make sure I'm not missing something else...

[siwelwerd]

I typically use wyeast american ale and london ale yeasts.

1028 gets pretty good attenuation, I use 1968 in all of my bitters, milds, etc. to keep them from going too low.

[Ozwald]

What are you using for a mashtun & manifold?

[Hoont]

What are you using for a mashtun & manifold?

I am using a 9 gallon pot with a false bottom for my mash tun. Pretty much this setup here:http://www.homebrewing.org/2-Weld-9-Gallon-Stainless-Steel-Brew-Pot-_p_1684.html The pot,the false bottom, the thermometer and the valve.

[Ozwald]

First I wouldn't recommend firing your MLT unless you're recircing. Assuming you're stirring correctly & for long enough, you shouldn't have hot/cold spots, but heat loss could be an issue. A Reflectix jacket could help with that. Your grain bill could very likely be the issue. You can't take a higher gravity beer & scale down the exact recipe to make a session beer, you'll need to do some adjustments, such as adding CaraPils or any other number of things that are less fermentable. Conditioning your yeast is a pretty advanced technique, but it can help as well. If you're doing starters, don't pitch at high krausen. Fermentation temp/stability could also contribute.

I'd recommend picking a recipe & brewing it multiple times, since it sounds like you're still having trouble with your mash, whether it's the cause of the attenuation problem or not. I like blondes because they're cheap & don't mask the flaws you're trying to fix. Something as easy as 85% 2 Row, 10% Wheat Malt, 5% CaraPils, aim for 1.042 & 16 IBU's. Make sure you get a really good stir (look at the 2nd post in this thread) and write down the temp reading every 5 minutes for an hour. I like to plug that into a spreadsheet, so when you do it 4 more times, it's really easy to see any inconsistencies. Nothing wrong with stirring in the middle of the mash or even before every reading.

The main point is, if you know that your mash is solid & you're comfortable with it, you can rule it out as the cause of other problems. If you do the same with other steps in your process, you'll eventually rule out enough things & discover the problem... and possibly fix other problems along the way. Be methodical, take more notes than you think you'll need (my early recipe sheets had the weather report on them) & you'll get there.

[Hoont]

Thanks for all the great advice. Last week I stirred for a good 5 minutes making sure to get every inch of the kettle and still there was wide variety of temperature in the mash depending on where I put the probe. I think you are right, I'm dealing with heat loss. I'm going to look into building some sort of jacket to keep the heat in.

As far as temp stability during fermentation, I am using a dual stage controller in a fridge with a heat wrap so I think I got that covered. I make a starter 90% of the time and I might be pitching at high krausen (24-28 hrs) so that is definitely something I can try.

As far as recipes... I've listened to the Brew Strong show regarding Session beers over and over. I just about always use cara-pils, mash higher.. I've tried flaked barley and flaked wheat. I definitely try to add more variety of grains to 'fill the gaps' per-say. And the beers come out okay.. they are certainly not getting dumped.

Taking copious notes I'll definitely work at too. But brewing the same recipe, back to back, is tough. I do brew the same recipes but spread out over months. I'll get there... it just might take longer.

Thanks again!

[Ozwald]

Sounds like you're doing the right things with getting your mash set & running - I'd definitely look into doing a jacket. A roll of Reflectix is pretty cheap, add some velcro tape or some other cheap, easy fastener & you're done. It works pretty well. I think the hardest part is lining up the holes for valves/thermo, especially if you do a double-wrap.

Regarding yeast, try this for your next session beers. Do your starter 5-7 days in advance. When it's completely fermented out & you have your cell count, crash & rinse. Leave it in the fridge until you dough in, then just leave it on the counter until you're ready to pitch it.

As for the same recipe over and over... yeah it gets boring after a while, but it's worth it. Think of it like homework. It may not be exactly what you want to be doing (but you're still brewing & drinking), but focus on the end result. Freshman year math classes may suck or be boring, but if you stay focused on getting that doctorate... and then when you finally get there, you can look back & appreciate them for what they were. They'll teach you a lot about your brewing style, give you plenty of opportunities to test different things with a methodical scientific process. I wouldn't know half the stuff I do now had I not gone that route... and now that I'm building a new system, I'm doing it all over again. Just about the only thing that's come out of my kegerator for months is blondes & browns. Boring, but I'm learning all over again. I just raid the cellar & buy commercial more frequently.

Regarding recipes, this is why I don't give out my recipes or even try to brew the ones given on the show - although I frequently plug them into ProMash & play around with them. There's nothing secret about my personal recipes, but there is one thing special about them. They're tailored to my system & my style. If I gave you my recipe, you won't brew my beer. If I brew my recipe on your system, it still won't be my beer. You can talk all sorts of different things that can be adjusted, like efficiencies, but there's some things like hop utilization that my recipe won't help with at all. Kettle geometry & materials. Burner style & distance from the bottom. The list goes on. That example I gave you in the last post is just a general guideline. Maybe you need 8% CaraPils to replicate what I get with 5%, it could be any number of things. The only way to really figure that kind of stuff out is to do your 'homework'.

Brewing a good session beer is tough. There's nowhere for flaws to hide. Attenuation differences of 1-2 points stand out way more than they would had your OG been bumped up 10 points. Of course all of this isn't necessary at all. Just like I tell people who are getting ready to brew their first batch, you can take this hobby as far as you want to. If someone is happy with the beer they're producing & don't feel like going through all the work to put that extra polish on it, by all means do what you're doing & enjoy it. There's certain techniques that I've tried & decided that they do indeed help, but weighing the amount of improvement against the amount of work, they're not my thing. If you are going to geek out & fine tune things, just remember scientific process. Be methodical. Change one thing at a time & look for repeatability. Back to the CaraPils example, trying 5% on one batch & bumping it to 8% for just the next batch doesn't tell you a damn thing. If you bump it to 8% & can repeat the results reliably (good or bad), now you've learned something. It's all about doing your 'homework'. And just like the doctorate analogy, it's only for a set period of time. You get to the point where your hypotheses get more solid & reliable, trying new things gets much, much easier. But there's always more to learn.

I'm not implying that you're not aware or knowledgeable of some of my points, but in trying to paint a more complete picture, giving the lurkers who may not & just generally being on a roll after not being able to sleep tonight... It is what it is. Cheers.

[EagleDude]

I'm guessing this mash temperature is the root of my thin body problems. I mostly make session beers starting out at 1.039 to 1.046. The problem is they are finishing out at 1.006 to 1.009. I can't seem to keep much residual sugar. I attempt to mash high 154 to 156 but with the wild swinging temperatures, I may have cold spots that keep drying out my beers. I do some step mashes but typically I'm single infusion, batch sparge. I mash in a kettle on the stove top so I can add heat (by the way, I never seem to scorch; there is about a gallon of water under the false bottom).

So what if mash temp is not my thin body problems... what else would cause me to finish out really low consistently? I typically use wyeast american ale and london ale yeasts. I just made the mexican logger with White Labs Mexican Lager and that finished out at 1.006 as well. I did verify my hydrometer, refractometer and thermometer are calibrated. Just want to make sure I'm not missing something else...

Good post and discussion here. As reading through it, the question just changed to finished beer body which is linked but a bit different than mash temp readings ... issues may go beyond just the mash. If you have a great mash held steady at 154 for the entire mash getting your wort to exactly the right place for fermentation, you can still "screw-up" the beer if that wort cools below 154 prior to denaturization of the enzymes. The mash temperature determines how active the different amylases will be which determines fermentability and body. As temperature changes, the activity levels of the amylases change accordingly. In order to stop this process, you have to raise temps to a level where they will denature. As such, if your wort drops from 154 into the low 150 and into the 140's, you just made yourself a highly fermentable wort that will dry out and have a likely thin body.

The fix is to be sure to conduct the mash-out step in one way or another. This can be done by raising the entire mash temp to ~168 and hold for ~15 minutes (many ways to do this depending on your system). Alternatively, you can be sure to maintain the mash at no less than 154 and be sure to heat the collected wort to above 168 as it is collected (i.e. sparge into a slowly heated boil kettle so that temps do not drop post-sparge/pre-boil and the enzymes get denatured in the wort instead of the mash.

As mentioned in prior posts, using dextrin or carapils malts will also increase body of the beer. Not sure if this is your issue or not, but it is a common problem with homebrewed all-grain beers.