Low attenuation please help!

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andyveedub

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I've been brewing for a couple months and had most of my beers turn out well. For some reason the last few batches have been finishing at 1.020 ish. I'm really racking my brain to figure this thing out. I have 3 thermometers that I use to ensure my mash temps arent too high. for darker beers I've been mashing at 154 to get a little fuller body. My IPA's though, I mash at 152, follow mr. malty to pitch an appropriate sized starter, my sanitation is excellent. I use yeast nutrient. And on tuesday night I got a stir plate and made a starter per mr. malty for a beer that will be somewhere in the 1.066 range. I made the starter which was calculated on a stir plate to be 1.05L. when I put the wort into the flask it measured more like 700ml. I have never measured my starter wort volume before pitching. so its possible that I've under pitched my last few batches. Just for an experiment though I checked the gravity of the starter after 24hrs on the stir plate and my gravity at 60 degrees was only 1.016. How come I cant get better attenuation? BTW I'm using WLP001. After I stuck the flask in the fridge overnight this is the size of the cake I got. Looks sort of small to me. Or is that a proper amount? It doesnt look like much more yeast than the vile...? The OG of the starter was 1.040.
IMG_0461.jpg
 
Are you oxygenating? What is the grain bill--are you using a lot of specialty malts (Crystal, etc...)?
 
All grain only. I've been going by the general 100grams of DME per liter of water. I dont use any oxygenation equipment but I cap the carboy and shake it and roll it on the floor for 10 minutes. the grain bill on the IPA was as follows with WLP001 yeast:

11.5# 2 row
1.25# crystal 10
1# carapils
.5# caravienne
 
All grain only. I've been going by the general 100grams of DME per liter of water. I dont use any oxygenation equipment but I cap the carboy and shake it and roll it on the floor for 10 minutes. the grain bill on the IPA was as follows with WLP001 yeast:

11.5# 2 row
1.25# crystal 10
1# carapils
.5# caravienne

It could be the amount of specialty grains.
 
20% specialty grains does seem to be a bit on the high side...What were the OGs and FGs?
 
I dunno, with 20% specialty grains that's not totally out of the ballpark. It would make a bit more sense if they were darker, like crystal 60 or something, but you could still have a bunch of dextrine in there.

I dont use any oxygenation equipment but I cap the carboy and shake it and roll it on the floor for 10 minutes.

Also, I don't think your aeration method is actually introducing any extra oxygen into the wort because the carboy is capped. You are only mixing up what air is already in there, which is the same amount of oxygen as if you had just pitched and put on the airlock. What does anyone else think about that?
 
I spent a few buck for an Aquarium pump and cheap air stone. My brews have turned out a lot better since then. Just clean the stone good before and after. I soak mine in Starsan for 12 hours after I use it, let it dry good and store it in a sealed container.

I also had to get an inline air valve because the bubbles kept coming out the top of my fermenter. I run it for 15 minutes. Works great for me.
 
You said you calculated the pitching rate for a 1 L starter, but then placed it in the flask and it was 700 mL??
The picture above shows about 1.2 L. How are you making the starters and what was the volume of the starter? Are you making it directly in the flask or are you making it in another container then transferring to the flask? It's possible the starter was not large enough.

I always add the DME (weighed out) in the flask then add enough water until it equals my final volume then add nutrient and boil for 15 min..
 
I dont trust the non pyrex flask I have with boiling in it. That starter was a 1L. I measured out a little more water to account for boil off. call it 1.1L. I use the ratio of 100 grams DME per liter of water. after a slow boil for 15 minutes I only had about 800ml. so I took a gravity reading and it was 1.060! I added enough boiled water to dilute it to 1.040ish. let it sit on the stir plate 24hrs then refrigerated because I wasnt going to be using it for 2 days. It just doesnt look like much volume to me. Should I pitch that or start over?
 
I don't see any reason why the starter shouldn't be good. I typically let mine go 48 h before cold crashing, but all activity should be complete within 24 h. To make only a 1 L starter, I assume your yeast had to be pretty viable. I also haven't topped off my starters before because I haven't seen anywhere that said it should be done. Not that I believe that is an issue or anything, I just don't have experience doing that.. Do you aerate the wort before pitching the starter? I'm not sure the starter is the issue here, but I wouldn't rule it out at this point..
 
I shake it around in the flask or growler depending on how I'm doing it. If I'm doing 2 beers back to back I only have 1 stir plate so I have to do one on the plate and one with intermittent shaking in a growler. I just bought an aquarium pump and diffuser stone today so I'll start using that. If I use that how long should I aerate the starter? 10 minutes good considering the volume?
 
I think you'll find that you won't be able to aerate that long with a pump due to bubbles coming out of the flask. If you only do intermittent shaking or aquarium pump then the starter will have to be larger due to less growth.
 
I just shook mine every hour that I could for the first 18 hours. Only have done one so maybe I'm not the most reliable source
 
Not to stray too far off topic, but my friend and I are getting ridiculous attenuation with dry yeast. With US05 we've done IPAs, APA, Brown, Rye IPA and they've all either over attenuated, or we've hit our numbers. We used US-04 on a 9.5% Impy stout, and nailed our numbers perfectly, with an insane fermentation. We're not doing starters either. Rehydrate, cool to pitching temp, pitch. I started with dry yeast (like most people) when I first started brewing, then I went to liquid, now I'm back to dry. I started having attenuation issues with liquid yeasts--starters and all--as well. Just some food for thought.
 
Was thinking if you are fermenting outside it could be getting colder than 68 in a temp controlled fridge.
Im no expert, but I dont think you have a starter issue. When I started I brewed a few beers with no starter at all. They didnt turn out so well, but there were no attenuation issues.
 
Not to stray too far off topic, but my friend and I are getting ridiculous attenuation with dry yeast. With US05 we've done IPAs, APA, Brown, Rye IPA and they've all either over attenuated, or we've hit our numbers. We used US-04 on a 9.5% Impy stout, and nailed our numbers perfectly, with an insane fermentation. We're not doing starters either. Rehydrate, cool to pitching temp, pitch. I started with dry yeast (like most people) when I first started brewing, then I went to liquid, now I'm back to dry. I started having attenuation issues with liquid yeasts--starters and all--as well. Just some food for thought.

+1

Honestly I don't see any good reason to use liquid yeast unless you need a special strain for a Belgian, Hefeweizen, etc. Dry yeast like S-04 or S-05 provides a clean ester profile, is cheaper, higher cell count per pack, stores longer/better viability, and you don't have to plan ahead days in advance or mess around with starters. IME they also attenuate better and result in a more compact yeast cake/clearer beer.

*shrug*
 
andyveedub said:
Well how does everyone else aerate their starters?

Most do intermittent shaking. The nice thing about Mr malty is you can choose this method to determine the appropriate sized starter. I started with an aquarium pump then went to pure oxygen and now I finally got a stir plate to reduce the starter volume. It also reduces the need for stepped starters
 
andyveedub said:
I dont use any oxygenation equipment but I cap the carboy and shake it and roll it on the floor for 10 minutes.

this is a problem. no oxygen is being added because you capped it shut.

at least toss the wort back n forth among sanitized buckets a few times, until it gets foamy!
 
Or you could get a siphon sprayer to use when racking to the carboy. I used that before getting an oxygen system and it worked great without having to shake anything.
 
what kind of aquarium pump? like from the local pet store?
Sorry for the delay, weather and all you know.

I got all my stuff at Pets Smart. I got the smallest one they had and it works great. I spent less than $20 I think for Pump, tubing, air stones and valve. As sjbeerman pointed out, unless you get a flow control valve for the air tube you WILL have bubbles coming out of the flask.
 
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