Brewing issues

[Buxton]

Hi folks, we are new to this (a mate and myself) but we have started full grain mashing and brewing. We have followed book recipes to the letter and learned a lot from that batches we have done.

batch 1 - ended up smelling eggy so chucked

batch 2 - ended up smelling vinegary so chucked.

we bought some new sanitiser and scrapped the pH powder that we had been using (thought it may be contaminated).

batch 3 - smells great (gas from bubble trap). I’ve tested the OG/FG and found that it is only 2% . Starting wort was 1.0359 and wort 7 days later was 1.0197. The bubbling has stopped so I feel like I should be priming now ready for bottling. My questions are around why the ABV is so low. Could it be I measured the OG wrong? (I measure the first wort, then the wort after sparging each of two times - I term the OG as the wort pre boiling and hopping. I measure it with a refractor yet and convert the Brix units), is it likely that the fermentation was really done in 6 days (it stopped bubbling then but had previously been bubbling frantically). There is a good smell and the run off that I test smells like beer.

batch 4 - currently bubbling frantically but smelling quite yeasty so jury is out unless I don’t get that lovely beer smell in the next couple of days... my batch 2 smelled similar.

overall, clearly the first 2 batches were contaminated but I would be really disappointed if batch 4 is contaminated too. We are obsessive about sanitising everything. We do boil with the lid off (so we can watch the hot break etc). Just interested to know what folks are contaminating their brews with.

 

[Herm brews]

Welcome to Brewers Friend. Luckily for me, I haven’t ever had any contaminated batches. Are you using plastic, glass or stainless steel for fermentation? In order to properly sanitize, you must first make sure everything that touches your beer after the boil has been thoroughly cleaned. Clean to remove any chunks or residues, then sanitize with a good no rinse sanitizer - I use Star San (don’t fear the foam). Good luck to you and your mate!

 

[Buxton]

Welcome to Brewers Friend. Luckily for me, I haven’t ever had any contaminated batches. Are you using plastic, glass or stainless steel for fermentation? In order to properly sanitize, you must first make sure everything that touches your beer after the boil has been thoroughly cleaned. Clean to remove any chunks or residues, then sanitize with a good no rinse sanitizer - I use Star San (don’t fear the foam). Good luck to you and your mate!

we use a stainless steel boiler, transfer to an insulated plastic mash tun (we do batch sparging of 2 x 14l sparging with a 12.5l initial mash). Then transfer to a stainless boiler for addition of hops while boiling, then we cool with a copper coil (takes about 10mins max) and transfer to a plastic fermenter with a tap. Everything is washed and then sanitised. Excess is poured out and nothing is dried. Everything eg thermometers or spatulas are rinsed and then resanitised between use. I sanitise the ‘smack pack’ yeast sachets and the scissors for opening them. Once the yeast is added the lid is applied and it sits there for about 7 days before bubbling stops. I then measure gravities for 2 days and if no change (the point I’m at now), I was planning to prime it in sugar solution (boiled) in a new sanitised fermenter - leave it 24hrs and then bottle.

all I have done is make sure I replaced the sanitiser and pH buffer (in fact we no longer use a buffer, we just use tap water to prime the boiler). Since we changed the sanitiser things have improved but I can’t work out why the ABV of this next batch seems low. When do others measure their OG and FG?

 

[Buxton]

I may just buy some new fermenters. That could be my answer

 

[Herm brews]

Original gravity (OG) is measured after the boil. It appears you are using pre-boil gravity as your OG. If you have a hydrometer, that is a great tool to use along with your refractometer. Hydrometer readings must be corrected for temperature (there is a calculator on this site). Also note that a refractometer does not give a true reading when alcohol is present. The refractometer will give a higher than actual reading when alcohol is present - there is a correction factor that must be applied.
As for those batches that you dumped, it might be that you did not give the yeast enough time to clean up. I usually keep my batches in the fermenter for at least 3 weeks - patience can be your friend in brewing.
Plastic fermenters work well, as long as you don’t scratch the plastic when cleaning. I use only a soft cloth to clean my fermenters (a Speidel 12 liter, and a FerMonster 3 gallon), both of which I can put my hand and arm inside to clean.

 

[Sunfire96]

When calculating your FG using a refractometer are you adjusting for the alcohol that's present? The alcohol affects how the refractometer measures the gravity of the beer. You will need to know the gravity of the beer right before you pitch the yeast (original gravity) after its been boiled.

Are you adding your copper chiller to the boiling wort to sanitize before using it?
Ate you removing your plastic spigot from your fermenter and thoroughly sanitizing?

I ferment in a plastic fermenter with a spigot and have not had contamination issues (knock on wood) so I know it can be done successfully

Good luck and keep us posted with how the beer turns out

 

[Ward Chillington]

Hey ,welcome to the forum.

Your ABV is spot on for your Lower OG. Think of it this way, the higher OG is going to yield a higher ABV if the yeast can do its job.

Tell us about your water and the quality of the yeast you are using. It sounds like you are using liquid and you are pitching it direct; are there enough cells for your batch? How old is it and did you and your shop keep it cold in storage?

What's the quality of your tap water? Is it treated with softening or chlorine or other chemicals?

Finally, what's the condition and material of your fermenter? Tiny scratches in a plastic fermenter is a common hiding place for contaminates. Are they food grade?

Hang in there, we'll help you solve this since not only do we want to brew good beer, we want others to do so as well!

 

[Buxton]

Original gravity (OG) is measured after the boil. It appears you are using pre-boil gravity as your OG. If you have a hydrometer, that is a great tool to use along with your refractometer. Hydrometer readings must be corrected for temperature (there is a calculator on this site). Also note that a refractometer does not give a true reading when alcohol is present. The refractometer will give a higher than actual reading when alcohol is present - there is a correction factor that must be applied.
As for those batches that you dumped, it might be that you did not give the yeast enough time to clean up. I usually keep my batches in the fermenter for at least 3 weeks - patience can be your friend in brewing.
Plastic fermenters work well, as long as you don’t scratch the plastic when cleaning. I use only a soft cloth to clean my fermenters (a Speidel 12 liter, and a FerMonster 3 gallon), both of which I can put my hand and arm inside to clean.

Thank you for this. Great advice. The first batch really did smell horrible and there was almost no bubbling in the bubble trap. I’d be surprised if that would have made anything palatable.

the second batch did bubble pretty well but smelled like vinegar.

would you normally leave it in the fermenter for 3 weeks every time (even if the OG/FG ratio seems to show you’re fermentation is complete)

 

[Donoroto]

It varies. I generally leave it in the fermenter for twice as long as it takes for the bubbling to stop. So if bubbling stops on Day 5, I transfer out of the fermenter on Day 10. This allows the yeast to complete the fermentation process and convert any off-flavors (such as Diacetyl), a process which is important but does not produce CO2 (so, no bubbling).

It can be left in the fermenter 2 or 3 times that (e.g., 20-30 days) without harm. Other than your own thirst not being quenched...

 

[Minbari]

aside from any possible contamination or infections. Patience is your friend! that eggy smell is ussualy caused by sulfur and is totally normal for some yeast. it will clean itself up near the end of the fermenation cycle.

the vinegar one was prolly some brett contamination. you are gonna want to sanitaze the hell out of that or it will just come back with every batch after it. boiling water for 10-15 minutes and/or a strong batch of iodofor.

advise I would give to anyone new. post-boil, ANYTHING that touches the beer needs to be hospital grade sanitized, lol. includes sampling and diptubes/thiefs for samples. I keep a bucket of starsan on hand at all times.

 

[Buxton]

When calculating your FG using a refractometer are you adjusting for the alcohol that's present? The alcohol affects how the refractometer measures the gravity of the beer. You will need to know the gravity of the beer right before you pitch the yeast (original gravity) after its been boiled.

Are you adding your copper chiller to the boiling wort to sanitize before using it?
Ate you removing your plastic spigot from your fermenter and thoroughly sanitizing?

I ferment in a plastic fermenter with a spigot and have not had contamination issues (knock on wood) so I know it can be done successfully

Good luck and keep us posted with how the beer turns out

ah no, I’m not making any adjustments at all. I just fire it on the plate, measure the Brix and convert it. How would you convert to account for alcohol?

I also hadn’t taken the spigots apart and sanitised them separately so that is a really great point.

water is chlorinated tap water but of course it is heated to 85 degrees C so I’m confident it will be softened somehow. I was going to send some away to get it tested and see if there is something I can add (even if I need to buy a RO system).

I sanitise the coil and then put it in the boil for the last 5 minutes.

 

[Minbari]

ah no, I’m not making any adjustments at all. I just fire it on the plate, measure the Brix and convert it. How would you convert to account for alcohol?

I also hadn’t taken the spigots apart and sanitised them separately so that is a really great point.

water is chlorinated tap water but of course it is heated to 85 degrees C so I’m confident it will be softened somehow. I was going to send some away to get it tested and see if there is something I can add (even if I need to buy a RO system).

I sanitise the coil and then put it in the boil for the last 5 minutes.

most city water has chlormides as opposed to chlorine add for sanitation. you can boil it for a month and it will still be there. it will contribute alot of bad flavors to beer. happily you can treat it for (nearly) free. look up camden tablets that just about instantly release chlorimides.

 

[Dogwood]

This time of year, fruit flies will destroy a.batch, only takes one! I've lost a couple of batches through the years!

 

[hundel]

I also hadn’t taken the spigots apart and sanitized them separately so that is a really great point.

That would explain the contaminated batches. Those dark nooks retain moisture and create an environment where microbes can flourish. Give everything a good cleaning, consider putting all of that through the dishwasher on sanitize as well. No need to sanitize the coil since it was at sterilizing temps for 2 minutes.

Now to figure out why you ended up with such a low OG (or OG reading). If your grain was crushed properly, that much grain in sufficient mash water at 64-72C has got to produce more fermentable sugars than that. A temp-corrected pre-boil reading is useful because you still have time to properly correct unexpectedly low gravities. A post-boil reading is essential so you can adjust fermenter volumes for unexpectedly high gravities.

 

[Herm brews]

Thank you for this. Great advice. The first batch really did smell horrible and there was almost no bubbling in the bubble trap. I’d be surprised if that would have made anything palatable.

the second batch did bubble pretty well but smelled like vinegar.

would you normally leave it in the fermenter for 3 weeks every time (even if the OG/FG ratio seems to show you’re fermentation is complete)

I am glad to help where I can.
My process is single vessel, full volume BIAB no sparge using a 5.5 gallon SS Brewtech kettle. I always leave my batches in the fermenter for 3 weeks, and only check for Final Gravity (FG) after that amount of time has passed. Typically, bubbling in the airlock (bubble trap) only lasts for the first several days. The rest of the fermentation is the yeast quietly doing their clean up work. Since my batches are small (~2.5 gallons), I don’t want to waste precious beer on samples. During the brewing process, I check gravity at the start of the mash with my refractometer, then with hydrometer and refractometer at completion of mash. Pre-boil gravity is checked with both hydro/refracto, and both are used again at the end of the boil to measure OG. It is these dual measurements at certain times in the process that allows for the computation of a wort refraction index (WRI) correction factor. When I check for FG after 3 patient weeks, I only measure with the refractometer, and as long as the FG is close to what my recipe projected then I am confident that fermentation is complete. Then I bottle.
Check out this feature of this site for great information https://www.brewersfriend.com/stats/

 

[Buxton]

That would explain the contaminated batches. Those dark nooks retain moisture and create an environment where microbes can flourish. Give everything a good cleaning, consider putting all of that through the dishwasher on sanitize as well. No need to sanitize the coil since it was at sterilizing temps for 2 minutes.

Now to figure out why you ended up with such a low OG (or OG reading). If your grain was crushed properly, that much grain in sufficient mash water at 64-72C has got to produce more fermentable sugars than that. A temp-corrected pre-boil reading is useful because you still have time to properly correct unexpectedly low gravities. A post-boil reading is essential so you can adjust fermenter volumes for unexpectedly high gravities.

Brilliant thanks. For the low ABV batch my measurements were as follows:

Initial wort - 19 Brix = 1.0785
After sparge 1 - 12.4 Brix = 1.0501
After sparge 2 - 9.0 Brix = 1.0359

after 5 days fermenting - 5.5 Brix = 1.0217
After 7 days fermenting - 5.0 Brix = 1.0197

so I reckon this is just about 2% ABV.

I will definitely pull everything else apart and put the spigots through the dishwasher and sterilise the main tubs.

 

[Buxton]

So if I take my OG as being the hot wort at 67 degrees C before boiling, must I do a calculation to work out the correction for temperature. My logic was that taking a sample and adding it to the refractometer plate would cool it back to room temperature.

 

[Herm brews]

@Buxton what kind of beer are you making? That initial wort gravity (1.0785) is a pretty big number. Even so, after your 2 sparges, you are still not looking at an original gravity (OG). Your 1.0359 reading is before the boil, right? If so, you are reporting a pre-boil gravity. As the wort is boiled, the concentration of sugars increases, therefore you will have a higher post-boil (OG) than pre-boil gravity. OG is the gravity after the boil, just before pitching the yeast. I suspect your real OG is probably closer to 1.045, give or take. With alcohol present, your refractometer will always appear higher than it actually is.
As an example: I just measured a batch that was brewed on 9/6, OG 1.064 (remember that OG is after the boil). My refractometer reading today was 7.6* Brix, which would read about 1.028 on the specific gravity scale. After applying the wort correction factor that I have computed for my device, it turns out my current gravity is 1.012, which is exactly what my recipe predicted.

 

[Herm brews]

So if I take my OG as being the hot wort at 67 degrees C before boiling, must I do a calculation to work out the correction for temperature. My logic was that taking a sample and adding it to the refractometer plate would cool it back to room temperature.

My refractometer has auto temperature correction, so the reading before fermentation is exactly what is read. The presence of alcohol changes the way the light is refracted, thus the need for a wort refraction index correction factor. To figure a WRI correction factor, you need to have a hydrometer to compare the measurements. I take measurements of the same sample using a hydrometer and refractometer at the completion of the mash and again at the completion of the boil. These comparative measurements are necessary to determine the correction factor. It probably seems a little confusing. I can’t state this strongly enough that OG is the specific gravity after the wort is boiled. OG is not the specific gravity before the wort is boiled.
Here is some info from the Tools pull down menu on this site:
https://www.brewersfriend.com/refractometer-calculator/

 

[Buxton]

@Buxton what kind of beer are you making? That initial wort gravity (1.0785) is a pretty big number. Even so, after your 2 sparges, you are still not looking at an original gravity (OG). Your 1.0359 reading is before the boil, right? If so, you are reporting a pre-boil gravity. As the wort is boiled, the concentration of sugars increases, therefore you will have a higher post-boil (OG) than pre-boil gravity. OG is the gravity after the boil, just before pitching the yeast. I suspect your real OG is probably closer to 1.045, give or take. With alcohol present, your refractometer will always appear higher than it actually is.
As an example: I just measured a batch that was brewed on 9/6, OG 1.064 (remember that OG is after the boil). My refractometer reading today was 7.6* Brix, which would read about 1.028 on the specific gravity scale. After applying the wort correction factor that I have computed for my device, it turns out my current gravity is 1.012, which is exactly what my recipe predicted.

I am so pleased to read this. Thank you. We are brewing a Spring Beer - it is a pale ale but should end up around the 5% mark.

I guess I need to get some sort of Brix conversion device. Or perhaps just bear in mind that after fermenting, the Brix device will read a touch high. In future I will take my OG after cooling and pre adding the yeast.

I have just been taking more readings at every stage just so I can replicate and get a nice consistent brew each time.