Temperature Problems

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

taylor1354

Member
Joined
Mar 15, 2016
Messages
8
Reaction score
0
I've been a homebrewer for about 7 years now, all grain for 4. I had one or two really good years as an AG Brewer, but since then I have had difficulty making great beer. To me the biggest culprit is my inability to hit temperatures and get consistent extraction. I use BeerSmith 2.0 to calculate my infusions, however when I measure the temps, they are off. I wait 3 minutes for the temperatures to equalize. I then make adjustments by adding water. When I check the temp after the mash it is much different than when I started (5-8 degrees). The tun (insulated igloo cooler) sits on a padded chair for the duration. This messes up my mashouts and sparging steps obviously. I have tried to be more thorough in record keeping so that I can narrow down solutions, but clearly not doing a good job. So...

1- I mix water into the grains. Does this really create thermal pockets that can cause problems? (It's a suspended solution, so I would thing everything would homogenize)

2- Am I alone in this problem?

3-Can I get my grain bed to 165 degrees without a mashout? What temperature does everyone use for sparge water coming out of the pot?

Really, I haven't brewed in 9 months because my last 5-6 batches were somewhere between subpar and abysmal and I want to correct this. Because I like beer. A lot.

Thanks for your help guys!
 
How far off are you with the temps? I can't imagine the mash temperature taking what could have been a great beer and turning it into an abysmal beer simply by being off a few degrees... What is the rest of your process? Do you have temp control for fermentation? Do you aerate the wort when pitching yeast? Do you pitch enough healthy yeast? How do you package (bottles, keg?) and are you sure you're not aerating/oxidising the beer during packaging?

As for the temps, are you using your measurements to correct your beersmith water calculations? It's not infallable, if you put junk numbers in, you'll get junk out. Use the actual measurements to adjust your calculations and hone in on a proper target.

Three batches ago I made my own spreadsheet. I measured grain temp, pre-heated the tun as usual, put in the numbers and mashed in as it dictated. I was low by three degrees (I always have cold and boiling water available during mash-in to correct temps). I adjusted my numbers assuming my tun losses and misc losses (due to pouring the water in 40 degree weather) were assumed too low. The next batch was about 1 degree high. Adjusted slightly again and hit the number dead-on on my most recent batch.
 
The rest of my process is standard. I aerate 15 seconds before pitching dry, rehydrated yeast between 65 and 80 degrees. My fermentation is not temp controlled but stays in the basement that rarely tops 70 even in the dead of summer. I keg, but recently found out i need to be bleeding the oxygen from the keg. I had never done it before because i used to naturally carb without sealing the kegs and everything came out fine. I find my mash temps can miss by as much as ten degrees though it is normally 4 to 8 on the high side but sometimes low.
I dont correct beersmith calculations i simply add cold or hot water in 1 qt increments until I'm where i need to be. I used to use my own spreadsheet and my problems started when i began trying to use beersmith as a total brew program and really refine my process and recipes.
 
I'm no expert, but my suggestions would be as follows:

1) Take good notes, especially in this case regarding your volumes and temperatures. Take your strike water off the heat, allow to settle for a minute and measure temperature (record), pour it into the empty (preheated) tun, measure temperature (record). Add grains slowly, ensuring no clumps form and mix vigorously, then take temp (record). After that, add your hot/cold water to suit and proceed as normal.

Then, take those numbers and see how they match to the beersmith numbers. Adjust the assumptions made in the BS calculator as required so that the numbers match (that is, if the calc said "heat 3 gallons to 175 to hit 153" and you hit 149, change the input values in your equipment so that 3 gallons of 175 results in a mash temp of 149). Try again next time and try to hone in on your system's exact properties.

2) Aerate more (unless you mean pure oxygen, aerate for a few minutes if you're shaking/mixing/whatever) before pitching

3) Control your temperatures. Something as simple as a bucket with cold water controlled with ice packs will keep the beer at a more stable temperature which will improve the end product

4) Research and follow proper kegging techniques. Oxidation will degrade a well-fermented beer every time.
 
Brewed Saturday with a friend. We had similar mash schedules and we both hit and held our temperatures without trouble. His gravity was 4 pts over and mine was under by thirteen, biggest I've had in awhile. His sparge was over 40 minutes, he has a sprinkler in the top of his MT to regulate flow. Mine was probably under 20 min using a ball valve to control flow from HLT to MT, but the hose lays in a circle on top of the grain bed, creating a small current in the water. Could this circular motion be causing issues? Or is the 20 min sparge the issue? Should I just instal a sprinkler system like his or try to slow my flow and eliminate the whirlpool effect?
 
You need to calculate for the temperature of the grain when going into the tun. I always preheat my tun with about a gallon of approximately 150 degree water while the mash water is getting to temperature. I keep the grain in the house until ready to mash so it is always about 68 degrees. You need to be sure of the temperature of both the water and the grain to get an accurate mash temperature. I sometimes miss the mark and spend some time and change the amount of water in the mash correcting. If done relatively quickly you should not notice much difference in the finished beer.

Even being off 10 degrees should not make a good beer bad. It will change the mouthfeel and the degree of dry/malty that you get, but it should not make it bad.

Stir the mash very well, measure the temperature in several spots. If the is much difference stir some more. If the temperature is off make the corrections as soon as you can.

If you are batch sparging there is no need to do a mash out. I sparge with approximately 168 degree water. I don't think the temperature makes much difference. Hot water might wash sugars out of the grains more easily than colder water.

Make sure you have a good and accurate thermometer. I had a cheap digital but it was too slow to stabilize. I got a Thermapen and get stable readings in just a couple of seconds.

Sit and think about what changed between the time you were making good beers and later with the sub-par ones. Something did change. Water, equipment? Change something and find out if it makes things better. Maybe try bottled spring water. Or Campden tablets if your water is chlorinated.
 
A couple more questions:

1) What temperature are you taking your SG samples at? Are you letting the samples cool before reading?

2) have you considered batch sparging? If you're set on fly sparging, I'd suggest choking the flow a bit and extending your sparge time by 10-20 minutes at least.

3) did you buy the grains from the same place as your buddy? Crush could be an issue

4) Are you making sure you're volumes are correct? That is, if you want 5 gallons of 1.048 and you have 6 gallons of 1.040, you're off because your volumes are off.

5) Not a question, but get the hose off the grain bed. Build a manifold if you want to fly sparge, or else batch sparge.
 
I take my SG after I've cooled my beer and I temperature adjust it. I am set on fly sparging, I've decided to build a sprinkler manifold into the MT lid and use it to restrict flow. I'm not really worried about crush at this point but I will consider it if other steps don't improve the situation. I am accounting for volume in my SG math.
 
The question about crush was to determine if your crush is too coarse and you're not allowing enough sugars to be extracted. Do you and your friend get your grain crushed at the same place? It is a major factor in sugar extraction during mashing.
 
We use two separate homebrew shops, so it could be an issue. A friend of ours tasted the spent grain and mentioned mine was sweeter. My assumption was that the sugars were extracted and left behind. Is double-milling the grains a bad idea?
 
Well, could be different things, but the crush of the grain is a very common issue with respect to mash efficiency. You could ask the HBS to set the mill a bit tighter when they crush your grains (they shouldn't balk at that, and if they do, you might want to find another store). Double milling is fine, lots of people do it, but with all that extra fine material some people report stuck sparges as a bed of that stuff forms and doesn't allow water to pass through easily.

Another culprit is likely your sparge. If you're going to quickly you are not allowing the water to saturate the entire bed of grains in order to dissolve the sugars and extract them. A longer sparge combined with proper crush should net you a much better mash efficiency.
 
I'm a new brewer, and new to all-grain too, so take this with however large a grain of barley grist you want to, but my first all-grain was kind of a disaster in that I made a bunch of mistakes. Screwed up the sparge, temp was off, you name it. Still, the beer is drinkable and a buddy who is a connoiseur of beer said, when sampling it, "I'd pay money for that."

No way I can reproduce it, but the point is I lucked out even after screwing up a bunch of stuff. I decided to make as many mistakes as I can, as fast as I can, so I can learn from them. :)

My next all-grain was much better--I batch sparged and ended up with very good efficiency. All I did was this: I preheated my cooler tun w/ very hot water (swished it around to get the heat all around the tun), then let it sit for a while as I prepared other things.

Then I poured in 4 gallons of strike water, doughed in, and saw the temp drop to a bit below what I wanted (lesson for the future was have the strike temp a bit higher). I stirred with a paddle, checked temp, stirred a bit more, then let it sit. I had a higher grain bill than normal, going for a higher ABV at the end.

Here's what I discovered while reading afterwards: I should stir a couple times during the 60-minute mash. Then, when batch sparging, same thing (though not 60 minutes). It works well, I get good efficiency when I do it right.

I decided fly sparging is not for me, for this reason: I can just add a bit more to the grain bill if my results are low, and it costs, what? A buck? Maybe two? As Palmer says in his book, if I were a brewery and adding more grain cost $500, I'd be fly sparging, but as a home brewer, there's really no need. AND, it just takes longer.

Like others above, I'd suspect the crush. If your buddy is doing better, buy your next grain at his LHBS, have it crushed there, and see if it's better.

Finally: get your own mill.
 
I always had issues hitting mash temps until I changed one simple thing; I now add the grain to the water, NOT water to the grain. I heat up water to 170-ish degrees and add it to the mash tun, I don't even pre-heat it. I use a calculator to find the strike temperature. Once the water cools to the strike temperatue(around 165 degrees) I then add the grain. My mash temps are always spot on now.
 
Back
Top