Low Attenuation

I've gotten low attenuation for a bunch of beers now. They taste good, but just a bit on the sweet side. I usually overshoot my OG gravity by a few points and my beers usually finish around 1.020.

I've read other threads about this and how having a high mash temp can cause low attenuation. However, I'm pretty sure I'm mashing at 152. I mash with 1.5 qt per pound. Mashout at 190 with 4 gallons (I brew 10 gallon batches). Vorlauf and stir a lot. Collect about 12.5 gallons of wort. I use dry yeast for my ales and rehydrate them prior to pitching. My fermentation temps are usually in the low 60s.

I'm just throwing out my process because I usually consistently get a high FG.

Can someone help please?

I would double check the thermometers you use for mashing. Inaccurate thermometers seem to be one the top reasons for under/over attenuation.

check this
https://www.homebrewtalk.com/f36/attenuation-200306/

I dough in usually around 173 degrees then stir until I reach 153. Takes bout 10 mins. Is this too hot to dough in at?

How do you oxygenate/aerate? How much dry yeast do you pitch?

JonK331 said:

How do you oxygenate/aerate? How much dry yeast do you pitch?

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I aerate pretty well. I pour the wort back and forth between the carboy and keggle then shake it for 10 mins. I pitch one packet per 5 gallons, hydrate it before I do.

Are your recipes calling for a lot of crystal or caramel malts?

Another idea - try mashing your next batch at 148 and see how that impacts your final gravity.

hmmm. I'm in the middle of a batch right now and will try it. Will I get proper conversion at 148?

Shoemaker said:

hmmm. I'm in the middle of a batch right now and will try it. Will I get proper conversion at 148?

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148 is fine for conversion. If you really want to try and dry it out even more, mash for 90 minutes.

So let me get this straight, do you guys adjust mash temps based on styles? I brewing a pale ale now so a bit on the dry side would be good.

Shoemaker said:

So let me get this straight, do you guys adjust mash temps based on styles? I brewing a pale ale now so a bit on the dry side would be good.

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Exactly. Lower mash temps are going to produce a more attenuable wort - which means the ratio of fermentable sugars to non-fermentable sugars will be higher. That will producer a higher ABV with a dry taste & thinner mouthfeel. Higher mash temps will increase the number of non-fermentable sugars produced, leaving you with a sweeter end-product with less alcohol and fuller mouth feel. Note than in either case, you'll likely get just about the same amount of sugars... which means your target OG will not change. What you're changing is the type of sugars produced - a result of the action of different enzymes which have different optimal temperatures.

OK I overshot my OG today by 10 points. Looks like I'm going to have another sweet one.

I mashed at 149. I added my mashout of 4 gallons at 190 degrees but it only raised the temp to 156. Since I didn't reach 170 in my mash out, did this contribute to my increased OG?

Shoemaker said:

OK I overshot my OG today by 10 points. Looks like I'm going to have another sweet one.

I mashed at 149. I added my mashout of 4 gallons at 190 degrees but it only raised the temp to 156. Since I didn't reach 170 in my mash out, did this contribute to my increased OG?

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How big is your tun? What was your grain bill & mash water volume?

4 gallons @ 190 should have raised a 10 gal batch WELL past 156.

Something doesn't add up.

What are you using to determine that you needed 4 gallons of 190* water for mashout?
I agree with Tun that 4 gal @ 190* should have impacted it more than that.
My last 5g batch, software said 1.1g of 200* to get my mashout from 154*.
If using software, try upping the temp of your mashout water to see about reducing the quantity.

Shoemaker said:

OK I overshot my OG today by 10 points. Looks like I'm going to have another sweet one.

Click to expand...

These do not necessarily go together. Your OG is not directly related to your FG. The amount of fermentable vs. nonfermentable sugars (because of mash temp, adjuncts, specialty grains, etc.) and the attenuation and health of your yeast are the primary factors impacting your FG.

If you are consistently getting a higher OG than you want, then you need to adjust your grain bill. If you are using Beersmith, adjust the efficiency upwards. You are getting a higher efficiency, so can decrease your grain bill.