liquid to grain ratio and mash temperature

Post #1 made 8 years ago
i have now some 6 BIAB's under the belt and i'm getting the funny feeling that mash temperatures are working differently than with my previous 3v system.

i made an ordinary bitter 4 brews ago and had horrible time getting it to ferment out. ended in some 60% fermentation. i wanted full body and mashed at 69/70. my last two beers had similar problems. a stout that just plain stopped in 40% fermentation using 1084 yeast, and a blonde ale using 1007 german ale yeast stopped in some 45% fermentation. i ended up having to spike'em with sugar to get some alcohol in it.

2 days ago i made some american pale ale, mashed at 64/65 and it is fermenting like crazy now.

i'm still using the mash temperatures i was used to in my old system. the main change now is of course the liquid to grain ratio, which is much much thinner now. does that effect the mash and if so how so i can adjust?

Post #2 made 8 years ago
Hi kristfin, I can't help you with a technical answer, but I can tell you about my experience.

When I first started BIAB (I've never 3v) I was mashing at 66-67°C and while the beers were nice they were very sweet (under attenuating).

I found the sweet spot for my set up to be 64°C. I get a full bodied beer that ferments down to 1012 - 1008 (generally from 1050). Some beers still have a small amount of residual sweetness but I don't want to mash any lower for fear of having thin beers.

I brew with 37 litres of water for 27 litres post boil.

So all in all, I'd suggest mashing lower than you're used to until you find what works for your system.
"It's beer Jim, but not as we know it."

Post #4 made 8 years ago
I'm with hashie, for my TTL- inspired ales 64C is a sweet spot, sufficient body without an overt residual sweetness ferments to 1.010, 3-5% or more of spec grain is helpful of course (crystal, usually Caramalt or Caraaroma or both). That's at Maxi-BIAB L:G too, so around 3 or 3.5:1.

kristfin, I'd also check and/ or verify your thermometer, it could be reading a bit low perhaps.
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Post #5 made 8 years ago
Hi there kristfin,

This post here should help you out. (The link given in the second sentence of that post is worth a read.)

I haven't heard of anyone's fermentations stopping by simply changing to BIAB. Given this and the above my first step would be to look for another source of the problem such as a thermometer as Ralph mentioned. Digital thermometers and bimetal thermometers can often get out of whack.

Not much fun having fermentations stop half way :angry:.
Last edited by PistolPatch on 10 Feb 2011, 19:05, edited 5 times in total.
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Post #6 made 8 years ago
thanks. this was just what i was looking for. my googling needs improvement obviously. from the text i deduct that thinner mash should give better extraction of the sugars if anything. i'm going to focus on the calcium, ph, time and temperature for now.

i know that for the stout that stopped in 40% i was mashing around 70°c, but i forgot my water treatment, which means the mash ph was around 5,4 according to ez water and calcium around 5ppm.

for the next few brews i'm going to experiment with the temperature. perhaps its just easier to find the temperature sweet spot for my system and then control the residual sweetness through specialty malts, instead of messing with the temperature.

one is always learning (hopefully)

Post #7 made 8 years ago
:peace: kf,

Glad to hear the links were helpful. I have really enjoyed following your thread here and my apologies for not having the time to say, "thanks for the great read" in that thread. (I am not a very efficient forum poster :P)

What's worrying me is that, as far as I can see, you have been doing many changes to your system in a short period of time. What's worrying me, a lot more, is that you might be exactly the same as me! You don't want to be like me :lol:.

It took me three years to find a fault in my kegs. Brand new, 'top of the range' kegs so what could go wrong there? :lol:

What I know now, after a tremendous amount of pain :roll:, is that as soon as you have a problem, you need to slow down - dramatically - preferably reverse.

If your beers attenuated fully when you brewed traditionally, there is no reason why they should not do the same with BIAB. Think on this....

So, we get back to basics. Do you have a mercury or alcohol thermometer you use as a calibration thermometer? I hope so as mashing at 69 C / 70 C needs this. What thermometer are you currently using? What equipment have you added?

What someone should have rammed down my throat as soon as I had problems is, "Get back to basics." No one did this and so I searched for answers on the net that "matched" my problem and adjusted my system and procedures to suit :roll:.


Brewing a great all-grain beer is not hard. My belief is that it is actually easier to brew a great all-grain beer earlier in your career than later. There is a bit of anecdotal evidence to support this belief.

Why? Because as most brewers progress, they are more likely to get some sort of infection, rely on 'fancier' measuring basics and actually trust them, or add more equipment that further reduces their cleanliness and measurement capabilities. Simultaneously they will read more advanced information and use this advanced information as, "the answer," that will solve all their problems on their next brew.

I hope the above post doesn't come across as disrespectful. I'm hoping that it comes across as how brewers, like myself, often add or change things to solve a problem instead of doing the opposite.

I've never written on this before in such detail but I really hope it helps :think: :pray:
Last edited by PistolPatch on 10 Feb 2011, 23:42, edited 5 times in total.
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Post #8 made 8 years ago
good points.

i have a digital thermometer which i recently calibrated. then i have one thermocouple in the pid and a different type of sensor in another pid i use for fermentation temperature controlling.

i always use the digital thermometer as a "master" and reconsider if there is some discrepancy between the 3.

i'm adjusting to many variables at the time. so i'm going back to basic. make sure the temperature is right, shoot for the middle in mash temp, don't go overboard in speciality grains, be humble and thankful.

my next beer is going to be german pils. 100% german pilsner malt, mash at 64°c for 90 minutes, boil for 90, pitch with plenty of 2124. stop worrying and brew more.

Post #9 made 8 years ago
kristfin wrote:good points.
stop worrying and brew more.
You've hit the nail on the head there kristfin :thumbs:
Last edited by hashie on 11 Feb 2011, 05:53, edited 5 times in total.
"It's beer Jim, but not as we know it."

Post #10 made 8 years ago
Good on you kf,

It wouldn't be unheard of to find that you had two of your three digital/electronic thermometers put 'out of whack' at the same time. I say this because your problem is weird so the solution is probably weird as well (like my kegs.)

Seriously consider buying one of these very cheap but accurate brewing thermometers. They are stable and nearly always within a degree at mash temps which is pretty hard to find. (Check the brass bands regularly though.)

Hope all gets sorted quickly. Maybe do some "fast" brews until you get this sorted? In other words, if possible, skip the pils and do a pale ale, a Schwartzbier (with ale yeast) or a "crisp" kolsch. That way, you should find the solution quicker I'm thinking.

Last edited by PistolPatch on 12 Feb 2011, 21:06, edited 5 times in total.
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Post #11 made 8 years ago

I'm still reasonably new at this so hope i'm not stating something obvious to more expereinced brewers as yourself.

I recently had a few beers with low attenuation. The lower alcohol didn't bother me as they tasted great and weren't overly sweet to my palate, however I was wondering why I could never hit my FG marks.

I discovered via some other reading that post boil dissolved oxygen levels were a likely culprit. I dont have an air stone and haven't really paid much attention to this previously until last brew.

I had a slow start on last brew decided to give it a razz up with a vigourous splashing stir using sterilised spoon at day 2 1/2. This seemed to get things moving and the yeast did their job right to my recipe's expected FG.

From what I have read the yeast will only keep going until they run out of dissolved oxygen. This had not been a problem for me previously as I used a fairly rough (and dangerous) transfer technique and a 60min boil, however once I started a 90 min boil and bought a syphon it seems to have become more important as I have driven out that bit more DO and have not reintroduced it at transfer to fermenter.

With my limited experience I reckon if you've gone from 60 to 90 min boil this could be something to look at.


Post #13 made 8 years ago
i've tried to just pour dry yeast directly into the fermenter and not shake or do anything. when i did that, the fermentation was a slow starter, but fermented fully.

if you underpitch (not enough yeast) and there is not enough oxigen, you will get esters and it will stop short. i've tested that.

if you underpitch, but there is plenty of oxigen, it will strain the yeast, you will get esters, but it will ferment out.

i'm very anal with my process. try to do this exactly the same each time. i do not use O2, though, but after i cool the wirth and transfer it to the fermenter, I grab the neck of the fermenter, like a conservatives neck, and shake the living daylight out of it for 3 minutes. this has worked great for me in the last 40 batches. i just have 2 batches which are off and the scary thing is that it happened at the same time.

that said, my last batch was just fermenting out, no problems. i think this is all in my mind

Post #15 made 8 years ago
stux wrote:how are you transferring to fermenter?

syphon while cold?

Check this out : Venturi Aerating" onclick=";return false;. ... uri_Device" onclick=";return false; ... get-68218/" onclick=";return false; ... opic=49435

Who Me?, no not cold, just a couple real gentle transfers while still very hot for first few brews after I got larger pot. Old smaller pot just got tipped straight in. Think I'm sorted now. Hit expectd FG last brew.

Thanks Stux. interesting stuff. I like the venturi idea with cane, maybe wrapped in filter paper.
Last edited by Mick71 on 14 Feb 2011, 20:02, edited 5 times in total.
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