Never hitting FG, advice needed!

[barndoor101]

A little bit at our wit's end.

Setting the scene:
Myself and a mate Andrew started brewing together in Covid times in my flat (cleaning... was... a nightmare!!) "Balcony Brewing" occurred, armed with an old (but new to us) original PicoBrew, some custom firmware as the servers had long since gone offline and three corny kegs (plus all the attachments money could buy.. as ebay was alive and well and we weren't allowed out of the house!) we learn't brewing through trial and error, always striving for a simple but tasty ~5-7% new England style hazy IPA. Old fridges were purchased for temperature control on the balcony (with a heating band inside and the fridge connected to a two way temp control) cornys were submerged in ice baths for the cold crash.

Initially, OG was an issue, we realised we were asking way too much of loading the Picobrew with probably 50% more malt than it was capable of, spills happened, dry spots were discovered in the middle... alll the fun of brewing. We kept learning and kept going.

Current day:
Even with all those issues with the Pico, the results would have been fully drinkable, if *ANY* of the yeasts we've tried had gotten anywhere near their expected attenuation.
We've tried may different yeasts, ensured we had a strong OG with brewers sugar, tried protein boosters towards the end of the fermentation, even tried "non beer" yeast (like turbo-yeast) due to it's ability to withstand a larger range of temps.
We've treated the yeast addition process gently, so as not to disturb it. Done the opposite where we properly airate the fermentor after pitching the yeast.

Fermentor is a Fermzilla 50, with the plan to capture and re-use a decent batch of yeast once we're happy with the results, sadly, it's just not happening and it's really starting to suck.

We've upgraded pretty much everything to try and give the best chance of success. From PicoBrew to a Brewmonk 50, a heat exchanger for much quicker cooldowns after the whirlpool, tried carbing during fermentation and without.

At this point I think we just need a little bit of encourangement/advice, what could we have missed.

Latest brew:
https://www.brewersfriend.com/homebrew/recipe/view/1074621/lua-remix

We were looking for an FG of 1.012, got 1.026, and as always we're left with really sugary disappointment!

Water is always mineral water store-bought due to the crappy water profile round here.
How likely is over-pitching yeast to cause such early stalls?

Thanks, Matt

 

[jschein]

We can’t see your recipe, it must be marked private

 

[barndoor101]

We can’t see your recipe, it must be marked private

Whoops! Fixed thanks.

 

[Minbari]

What temp do you mash at?

Over pitch will not cause this, even an under pitch will not cause it in alot of cases, you will just see more off flavors and a longer lag time

 

[Donoroto]

How did you measure the final gravity? Hydrometer or refractometer?

I think that the question you might be wanting to ask is "what can cause lower attenuation?"

The list is long, including higher mash temperatures (try 145F), wrong ferm temperature (probably not), pressure fermenting (?), poor yeast nutrition (oxygen for liquid yeast, yeast nutrient for any yeast), and... (others may chime in with what I've left out).

 

[dmtaylor]

I see one odd item in the recipe:

Starting Grain Temp: 67.78 °C

That should be something closer to 20 C, or the temperature where you are STORING your grains, not the same as the initial mash temperature. If you assume that but don't measure the actual mash temperature, then the recipe is not accounting for the temperature loss from the hot water hitting the relatively cool grain. Typically there is a loss of around 5 C when adding hot water to cool grains. If so, you might be mashing not at 68 C but rather 63 C or thereabouts. Maybe.

There could be a multitude of other issues going on, such as @Donoroto alluded to, including refractometer vs. hydrometer, Tilt with schmutz stuck to it, uncalibrated mash thermometer (use both ice water and boiling water adjusted for your altitude), uncalibrated gravity measurements (check in plain water that it reads zero), poor crush of the grains (quite likely -- do you mill your own? or have a shop do it?), mash pH, etc.

US-05 is one of the highest attenuating yeasts, so it's not the yeast's fault. There is something wrong with your recipe or process or both.

 

[Craigerrr]

I would rule out oxygenation at yeast pitch "if" you are using dry US-05 yeast from a packet.

I feel like the two most likely offenders are either mash temperature, and or, mash pH.

Your recipe mash temp, approx 68C (155F), is fine.
Are you measuring, checking mash temperature?
How long are you mashing?

I would expect that you would need some lactic acid to bring the pH down with that grain bill.
My personal method of adding acid to the mash is to use some acidulated malt. I never test mash pH, I just trust that the software prediction is close enough.

Hope this helps!

 

[Prowler]

Maybe something to consider - I don't know your process. Do you elevate your water temp and then add your grain to try and meet your desired mash temp? I ask because I had similar problems early in my brewing process. I found some info that explained adding grain to "too hot" a temp can partially denature the extracted enzymes and make them less fermentable. Your gravity can read spot on, because the sugars were extracted, but some percentage of those sugars were exposed to water that was too hot. I ended up creating a process where I split my strike water, and kind of dough in twice. The water is never hotter than about 162 for either source. I have to elevate my temps a bit after I get my mash started, but I have been hitting my final gravities ever since. I was previously using the temp tools in BeerSmith and it would have me prepping my strike water to something like 167, for the volume of grain I normally use. It only denatures the grain that are in contact until the water drops down below, say, 165ish, but it was definitley more than nothing.