Attenuation Quandry - Extract Brew

[Propilotdave]

Hello fellow Brewers! Im taking a whack at a new brew/style and ran into this little ditty. Thought it would make for an interesting topic, perhaps.

Ive seen threads get sidetracked when style is mentioned and the thread goes to the recipe instead of the core issue so Ill keep that on the sidelines for now. The question is, considerign the controls/variables below how can I best align my yeast to hit my target attenuation?

Controls

1. Yeast attenuation 70-75% (Edinborough)
2. Extract 60% grist
3. 32% specialty malts (mostly Crystal)
4. 4% carapils/wheat
5. Here is the kicker - 5% molasses!
6. Pitching from 2nd gen slurry to a starter of undertimed size (under, on, over).

*Desired result - 70% attenuation*

The brew targets 8.5% ABV (fyi). No problemo.


Questions/Discussion Points

How would attempt to hit 70%?

Pitching rates, ferrmentation profile, process, etc all fair game.

Keep in mind, we have a high % of specialty malts which will reduce attenuation, but we have a simple sugar increasing it, no mash temp control to help our cause, and in the end I want the low end of the range...

OK fellow brewers, have at it!

PS. For fun, 5 Pliny Points, if you can guess the style (hint: infusion). I'll post the full recipe after the fact to allow for a proper internet-based roasting.

 

[unionrdr]

You could use a yeast calculator to determine the size of the pitch needed. With all that crystal, I big pitch is the first thing to do.

 

[CastleHollow]

How old is the slurry? Make sure you estimate initial cell size as accurately as you can. Do you have a stir plate?

Pitch appropriately, aerate generously, and begin your fermentation as close to 65 as you can, then ramp up to 70 after a few days. I would also add the molasses after primary fermentation has been underway for three or four days.

 

[unionrdr]

+1 to this^^^

 

[beergolf]

Using extract and that much crystal/specialty malts, I doubt that anything you do will get you 70% attenuation.

 

[boydster]

I don't know how you can get to 70% attenuation with the initial conditions you are laying out. Practically all extract will already have some specialty grains in it, but the percentage is anyone's guess, plus you want to add another ~36% crystal (I'm including the 4% carapils here, but it looks like an unknown amount of that is also wheat?) so if I had to guess, you're over 40% specialty grains in this brew to begin with.

A big pitch of very healthy yeast, plenty of O2, and ramping the temperature up to the warm end of the yeast's range immediately after peak krausen is probably your best bet to get the most attenuation. I'm just not sure you'll hit the 70% target you are after, but I wish you the best of luck!

 

[Calder]

You didn't say if you were mashing or steeping the grains. Some specialty malts have diastatic power and are highly fermentable. If there is some enzyme activity and the grains are being mashed, it is important to know.

Assuming you are steeping and get no conversion from the specialty malts, how are you calculating the percentage? The best you will get from steeping with the mid and lower crystals is 50%, so should the crystal be marked as 16% of the sugars? Darker grains will give up less sugars.

How do you arrive at 4% Carapils/wheat? If you are not mashing, the carapils/wheat will contribute zero to the gravity.

I assume you have listed percentages by weight. Since you didn't say if the Extract was DME or LME, we really can't figure out how much of the wort is extract (and fermentable). If you are using LME, you might have 80% of your sugars from extract. If you are using DME, that percentage may be much higher.

I don't think there is an answer to your question without more information.

 

[Propilotdave]

I've been all grain forever, time issues have me back in extract for a bit so this is an amazing refresh. Thank folks! Answers to questions.

1. I'm steeping grains
2. Extract - Lme is 3.3# - light golden, DME is 1# (it's just a 2G test batch)
3. 4% is C40, 8% is C80 the rest are C120, chocolate, wheat and Carapils. Excellent point on no conversion of the highly kilned grist! Beer Alchemy does not adjust for mashing vs. Steeping! You are saving my backside here!

In that case, and as a general rule of thumb when using beer alchemy for extract/steeping grains process, I can manually add half of the calculated contribution of lower kilned grains to the total OG th

Or, I just "steep" for an hour and it's a mini-mash, just have to add some 2-row in there for the enzymes. Thereby getting conversion..right?

With all this math I may as well just break out my mash tun


Great great info, thank you

 

[Yooper]

Right- except that it's not like crystal malt or chocolate malt will magically suddenly become more fermentable.

The sugars are fermentable, but not to a great degree like base malt. Highly kilned grains don't need to be mashed, as they are "preconverted" so to speak by the processing. You won't get much more of out of them via mashing.

It looks like your recipe may be more like 15% crystal malt, which is better, but I really can't tell from this last description.

 

[Propilotdave]

Yooper, great point, from all grain and using the software I havent thought some of this math through. Yes, much of the grst is purely unfermentable serving their own purposes from flavor (pale chocolate) to head retention (carpils and wheat), well played.

IM relearning my brewing software here as I assumed it would account for these things, but it seems to not. I put in 2lb of C20 (fermentable) and beer alchemy showed 7 gravity points. The I put in 2lb choclate and it gave the exact same. Plus I changed the setting for each from full mash to steeping grains and the numbers were still exactly the same. HMMMMMMM. I thought my software was more intuitive than that. I guess I was wrong.

All of this taken into consideration Im going to just rework the recipe. Its a Christmas/Winter Spiced Ale.

My "secret ingredient" to help this thing stand out is oak and 1 shot or whiskey per gallon (so just two shots), to bring up the "warming" character as dictated in the style guide.

Recipe Rework and associated math up for discussion - 2G final batch size, 90 minute boil, steep grains, 2L starter.

(52%) 3.3# golden light LME
(22%) 1.5# - Extra LIght DME
(3%) .25# Mollases
These give me 1.084

(7%) C20 - .5#
(7%) C80 - .5#
The software gives me 8 more points, Ill assume half that so 4 points. Now we have 1.088

(4%) C120 - .25#
(4%) Pale Chocolate - ,25#
No fermentables from these.

Now check this out. From the math above I should hit about 1088, but beer alchemy has me at 1094! If ive learned from the prior discussion, then with the steeping of grains process I should realistically be at 1088ish...right?!?!?

Recipe wrap up:
Spice additions at 1 minute (with care), oak to taste, and 1oz whiskey per gallon (2oz whiskey).

In the end we get what we get right, but Im just using this as a platform for understanding extract recipe formulation. Have only done all-grain recipes and just counted on the software.

Love the feedback, keep it coming and thanks in advance

 

[joey46987]

Looks like a WAY better recipe than the coconut puke bomb hehe.