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NBS Yeast

timothy4

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Hi All.  I am a fairly experienced homebrewer and have recently used NBS Classic English Ale Yeast and NBS West Coast Style Ale Yeast on my last two brews.  I have experienced issues with both brews and wondered if anybody else has had any (similar) issues with these yeasts? 

The NBS Classic English Ale Yeast fermeted out a Timothy Taylor Landlord clone in about 3 days flat and then sat there apparently doing nothing (F.G. remained the same over the remaining 7-10 days I left in my primary fermenter).  I have never experienced that with a yeast before.  I was wary about using NBS yeast in my next brew but went against my instinct and tried using NBS West Coast Style Ale Yeast.  I wish I hadn't now!  The 1.050 OG brew started ferementing vigorously within a few hours and went down to 1.030 in 48hrs according to my Tilt.  I contacted the supplier after it had sat at 1.030 for 24hrs and they advised that this yeast starts very quickly and would then tick over going down more gradually over the following days, however, I can report that it is still at 1.030 after 72hrs! 

Temperature control of my brews has been with an Inkbird so should not be the issue.  I drew of some wort today, double checked the gravity and then added some (bread) yeast to the sample.  The sample began ferementing very quickly showing that fermentables are still present in the wort.  Stirring up the yeast is the last resort, before doing that I am going to add some more yeast to try to get it fermenting again with a non NBS yeast I hasten to add.  This is really just a rescue attempt now to try to salvage this brew!

Yeast nutrients should not be an issue as I have many successful brews under my belt (some prize winning) without ever using yeast nutrient and my process has not changed on these last two troublesome brews.   

Any feedback or comments would be welcome, thanks.           
 
A second yeast probably won't help.

A fresh-from-the-factory yeast in all malt wort shouldn't need any nutrient. Nutrient additions show worth when you're harvesting and repitching multiple times. I go 14 to 20 generations, across 100 batches, commercially. Without nutrient, I see performance issues on 4 to 6 generations. So, probably this doesn't apply to you.

With the same performance on two different strains, you really don't have much o go on. If there is a nutrient issue, it'd be zinc. The cause could be in how they grow their yeast where there isn't enough zinc in their process. This is overcome by higher levels of oxygen when you're pitching. You can reoxygenate the wort, which *may* roust the yeast.

There are some English strains that struggle to get over 5% under even the best circumstances. A West Coast Ale yeast should have no such issues.

The above advice is taking your experience into account. All other factors I trust that you have measured and control. The pH of the fermentation should be around 4.3 to 4.5. A pH of 4.6 and above can cause the yeast to quit and flocculate. Underpitching could be a reason that the pH rises and stalls fermentation.

Then there's the usual suspects of malt conversion, hot break, sanitizer use, etc. You probably have that part under control.
 
Thanks for the reply.  Whatever the problem is will probably remain whether I put some new yeast in or not; so I can understand what you say about a second yeast.

pH I think maybe okay, but cannot be 100% sure as I only have 5.2 to 6.8 test strips, it is significantly below 5.2 but I guess could still be above 4.6!  I doubt it was underpitched as I used a whole packet of the West Coast yeast in 13.25l wort in my fermenter.

There was an obvious issue in my process where BeerSmith I think may have miscalculated mash water volume (I will post about this separately another time perhaps)or I measured it incorrectly, and I ended up with a very watery mash in my picnic cooler mash tun with concomitant problems getting to my target mash temp!  I suspect my mash temp may possibly still have been too high so I may have a surfeit of unfermentables in my wort, although the bread yeast experiment this morning would suggest not.

I do not think I will use NBS yeast ever again...
 
What were your mash temps? Zymurgy recently had a wonderful article showing a graph of mash temp/apparent attenuation. If you overshot your temperature by 10F there's a good chance that you destroyed your ability to ferment out the sugars. bread yeast has the ability to ferment many sugars that brewers yeast often cannot, hence the fermentation when throwing bread yeast.

per the zymurgy article, apparent attenuation at 63c/145f is 88% and up around 71c/159f it drops down to 67% so if you overshot your temp then its not going to finish any lower.
 
Initial mash temp I think was way up around 75c which I reduced quickly to 66c.  What you say about bread yeast makes sense, I might try the same experiment with brewers yeast the results of which may further suggest too high mash temp. was the issue.  I feel like I have learnt a lot from this...

The Zymurgy article sounds interesting.  Thank you for those apparent attenuation figures, very useful, I can clearly see how it will not go any lower if I was at 71c.
 
If you doughed in at 75C there's a really good chance you lost a lot at that point. I've done that once before at 71-72C and mine was underattenuated as well. I use a HERMS system so lately i've been doughing in 2 degrees cooler than estimated just because it's less harmful.
 
Doughing in a bit lower sounds like a good idea and can understand how this may be less harmful. 

Its a bit annoying, as when I did my own brewing calculations manually I never had any problems but now I use BrewSmith to do the calculations I have run into problems.  I am only only my 3rd brew using BrewSmith so I guess these things may happen until fully transitioned over to BeerSmith as it were.  I ironically, I decided not to purchase a Grainfather as I was already getting great results with my picnic cooler system and I liked the simplicity/low cost of it.  The main disadvantage of my cooler system is the stress of trying to hit mash temp. at dough in, lack of control/inconsistency in the process and all the time spent doing the recipe, equipment and water volume calculations manually, although I have never had a disaster until now using BrewSmith.  It is my mistake and I will continue to use it as I can clearly see the benefits outweigh the disadvantages.  I am seriously reconsidering buying a Grainfather now as well for the precise mash temp control and perhaps a more repeatable, consistent process particularly when I have more experience of BeerSmith and a fully optimised equipment profile etc.

The beer was meant to be a robust porter dry-hopped with Chinook, but given it is only going to be 2.75% ABV, I think I may not bother with dry hops and drink it as if it were a mild, albeit with slightly low ABV for the style, but at least closer to the style and potentially more palatable by leaving out the dry hops!   
 
You may have a great beer, even with the hop additions, having the higher mash temp and lower attenuation would be a great choice for a dry hop beer. The lower attenuation and sweetness would balance out the hop character quite nicely. I mash around 160F for my low ABV NEIPA.

Send your recipe via BSMX file with your profile and perhaps myself or someone can see where the issues are coming from, likely just a setup problem.
 
Sounds like you need to set  up an equipment profile in BeerSmith. The software is highly dependent on your input. If you have already done an equipment profile you need to make some adjustments in order to hit your mash temps.
 
Did you use a yeast starter? Do you know approximately how many viable yeast cells you pitched? It sounds as if your yeast did a whole lot of work very quickly and then weakened to the point of not being able to finish. There are two Beersmith podcasts with John Palmer about yeast that I recommend. I've watched each of them at least twice and pick up something each time.

http://beersmith.com/blog/2018/03/31/beer-maturation-and-yeast-with-john-palmer-beersmith-podcast-168/

http://beersmith.com/blog/2016/06/26/brewing-yeast-with-john-palmer-beersmith-podcast-128/
 
Thank you for the feedback folks.  That is very encouraging that I may have a good beer which would be good for dry hopping.  I can see the logic, and it is very interesting dtapke that you intentionally brew a low ABV NEIPA.  Maybe my mistake with the last brew is actually fortuitous, as I have to watch my body weight and also I do not enjoy being intoxicated so low ABV beers would suit me well!  This is part of the reason I also brew 20 pint batches as I never get to brew otherwise at the slow rate I am able to drink it!

I can understand that I have probably gone wrong somewhere in my BrewSmith profile which I have attached.  I ended up with a very watery mash which I think may be due to my 73% brewhouse efficiency.  Please note, this file was adapted from the .bsmx file provided by the homebrew supplier here https://www.themaltmiller.co.uk/product/robs-chinook-robust-porter/ which had this efficiency built into it. 

The watery mash does still not account for the high mash temp. as BeerSmith should have adjusted the mash liquor temp. accordingly.  Just to clarify, the original .bsmx file from the homebrew supplier was for the Grainfather and a 40 pint (23 litre batch).  I adapted it using my equipment profile and halved the grain bill, hop charges etc. Not sure why I used my equipment profile but also then lowered the BH efficiency from my usual 85% to 73%.  This does not make sense now I look at it...

Think I will now go and dry hop my low ABV beer  :)             
 

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  • ChinookRobustPorter_ForForum.bsmx
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Thank you Kevin, I will check out those videos.  I did not bother with a yeast starter, mainly because I used a whole 11g pack of dried yeast for a 20 pint (11 litre) batch which is about half the normal batch size for 11g dried yeast.  Maybe I overpitched...

I will watch to see what John Palmer has to say about it all, thanks again   
 
Briefly checked the recipe. I think your set-up is partially inaccurate, as well as some readings. You show a measured preboil gravity of 1050 and a post boil gravity of 1048. this is literally impossible. Did you calibrate for the temperature?

as far as dough in temp, it shows to add water at 74C, and a grain/mash tun temp of 16C, which should bring your temp down to 66C or so. Making accurate measurements is critical. Using your 4L/Hr boil off, if you started an hour long boil with 19L of 1.050 wort, you should end with 4.5L less, or 14.5L of 1.064 wort, (allowing cooling shrinkage) minus your stated loss to trub and chiller of 3L would bring you down to 11.5L of 1.064 wort. yet somehow you show that you ended with 13.25L of 1.048 wort.

something went wrong with measurements somewhere here... did you stir the dough in water and measure accurately? did you stir the mash when you doughed in? did you correct gravity readings for temperature? a 1.048 reading on 60C wort is in fact 1.064 which would be very close to your estimated number.
 
Also, If you pre-heat your mash tun, that dough in water temp will be effected. When i was using cooler mash tuns, I always preheated with boiling water, if you do this, adjust your mash tun temperature to 95C that will bring down your dough in water temp dramatically.
 
Thank you very much for looking at this dtapke.  Regarding the pre and post-boil gravities, these were taken from well mixed wort and measured using a refractometer which is calibrated and should have been within range of the ATC.  Both samples tested with the refractometer were hot wort but should have come down to ambient temp. once placed on the refractometer and throughout the time that I took the readings. Additionally, I measure the post-boil gravity with a hydrometer taking into account temp. correction.  So, those gravities are another mystery!

Mash tun and grain temp. were accurate as I measured them with a calibrated infra red thermometer.  Apologies, I had not entered the correct measurements into the BeerSmith 'vols' tab but recorded my measurements as Notes.  I  am wary of entering these data into the 'vols' tab in case I mess up my equipment profile.  I normally create another equipment profile using the actual measurements from my previous brew so that I do not mess up my previous equipment profile.  I may be too lost in my own confusion here to be rescued so I totally understand if you want to leave me to it!  Anyhow, I have reattached the .bsmx file with the proper measurements.  Basically, the volumes now all stack up, but the pre/post boil gravities still do not make sense of course.

I did stir the mash water well at dough in and think that I measured accurately as I am quite careful, but I cannot completely rule out a mistake.  I can understand the possible 1.064 gravity reading at 60c as this would equate broadly with the expected OG given the boil off volume but this is just not consistent with the refractometer, hydrometer and also the OG reading from my Tilt once in the fermenter (which measured 1.050).

I used to pre-heat my mash tun before I used BeerSmith but as I was not sure of the pre-heated mash tun temp. but knew the ambient temp. of the tun I have tended to use that approach. 

I would be please if you posed further dtapke, if you are inclined, but understand if you do not!  Many thanks.  Interestingly, I can still hear my fermeter expelling CO2 through the airlock about once every 5 to 10 minutes, but gravity is stuck fast at 1.050 as measured by my Tilt (and hydrometer).  I pitched another packet of yeast a couple of days ago but this has not really done anything...           
 

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  • ChinookRobustPorter_ForForumv2.bsmx
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Hard to say, seems like a multitude of issues, would be best to address them during your next brew day  ;)

bring dough in temp down a few degrees.

verify accurate measurements, its literally impossible to lose gravity points when boiling a solution.

you say the mash temp was nearly equal the dough in temp, this is nearly impossible. The bs calculations are inline with all known brewing information you can find.

I would run through the calibration tools for refractometer and hydrometer on beersmith to verify your equipment is accurate.

You may be losing more to cooler/trub loss than you've got put in if you're saying those measurements are even halfway close to accurate.

Just for reference, every boil off calculator you can find will say that if you go from 20L of 1.050 wort, and you boil off (you can only boil off water, increasing the concentration of sugars in the wort) 4L of water, you're going to end up with 16L of 1.063 wort.

as far as entering the numbers into the beersmith session data, it won't alter your equipment setup. so don't worry there.
 
Yes, I am sure I can sort these issues out in my next brew.  I do not doubt the impossibilities you highlight, obviously there were a catalogue of errors that brew day which I cannot really understand, so as you say I will just need to sort it all out in my next brew  :) 

I will take on board your useful comments and run through the calibration tools on BeerSmith.  I think I may have made a mistake when measuring out the mash water volume because if you saw the mash I think you would see how the mash temp and dough in temp were nearly the same as it was mainly water.  This does not mean that mash temp being nearly equal to the dough in temp is nearly impossible, merely that I was probably doing something way outside the realms of standard brewing practice!  I may have been a bit distracted of late...

The loss to cooler/trub should be accurate as I measured out using my measuring jug, although it is also worth calibrating jugs as well, I guess that is down my list of priorities.  The boil off calculators are interesting, I have never looked at them before or really thought about that too much...

Thanks for mentioning about entering session data should not messing up my equipment profile   
 
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