Comparing yeasts on the same beer recipe

[FunkedOut]

I have a porter recipe that I love. Always used US-05.
I want to try it with 1084.
My plan was to brew two 5 gallon batches and pitch US-05 into one and 1084 into the other.
Then have both on tap for some drinking fun.

Here’s the quandary...
In Beersmith, simply swapping yeast makes a huge difference in FG; 1084 comes out about 0.4% ABV lower.
I can adjust mash temp from 157*F to 154*F to bring it back up, but I’d think that alone might contribute to some difference.

Part of me says to simply brew the same beer twice, maybe even mixing them to ensure they’re the same, and simply pitch different yeasts.

How’d you compare these two yeasts?

 

[deadwolfbones]

Same recipe. Don't worry about ABV. That's part of the comparison.

 

[thehaze]

A 0.4% difference in ABV is negligible.

You are interested in finding out what the one yeast will bring more or less than the other.

If I were to conduct thius experiment, I would keep the same exact grainbill for both, same hop additions and IBUs, same water treatment and water profile, same mash temp., time, sparge, boil time, boil additions, fermentation schedule, fermentation time and packing.

You already know how US-05 will turn out. You now want to find out how the Irish Ale yeast will do, but this means you need to re-do the recipe, where the only thing different now is the yeast.

1084 is more estery and different than US-05, which is clean, more attenuating and perhaps dull, at least for me. I think 1084 will make a better Porter. But you will definitely find out if this is the case with your taste.

 

[Kent88]

Make a double batch, split it into two carboys, each gets a strain, put them in side-by-side in the same place to ferment.

 

[Jtk78]

I agree with others here. If a different FG is a result of the 2 yeast strains, that is result of the character differences between the two. Modifying the wort to achieve the same FG throws another variable in it.

 

[madscientist451]

Beersmith is giving you a different FG, but that's just an estimate. Your actual FG may vary.

 

[Griffin495]

When going by the Scientific Method, only change one variable at a time to test your hypothesis. If you change more than one variable, you won't really know which one (or both) caused the change that you observed. So in a straight up comparison of the two yeasts, the only change should be the yeast, not mash temperatures. That's what I would do anyways for whatever that's worth.

 

[madscientist451]

To expand on the above, instead of making two 5 gallon batches of wort, only make one batch and split it in half for the two different yeasts. You'll eliminate any chance that the wort may be slightly different.

 

[TimmyWit]

To expand on the above, instead of making two 5 gallon batches of wort, only make one batch and split it in half for the two different yeasts. You'll eliminate any chance that the wort may be slightly different.

I agree with this and I do this almost every batch. Most of the time, the yeast surprise me and I end up preferring a different strain than I anticipated. OP might even find that he/she can brew 7 or 8 gallons at a time on their gear especially with the help of a little fermcap.

 

[MrHopScotch]

The predicted FG is different because Beersmith considers the predicted attenuation levels of the yeast strains you are using. A strain with higher expected apparent attenuation will predict a lower final gravity. With that said, those predictions are generally a wide range, and the yeast behavior will depend on a lot of other variables like pitch rate and temperature.

I would keep the worts identical instead of trying to adjust to anticipate your FG. If one beer turns out slightly drier than the other then great, you have a better understanding of both yeasts behavior. Good luck!

 

[FunkedOut]

Appreciate the inputs.

I think I’ll go for the same wort this go around and see how it plays out.
A part of me was thinking that 0.4% ABV would have a significant effect on flavor (6.2% vs 5.8%).
I’ll see how it goes and then decide if I want to try anything else.


Totally understand the predicted attenuation aspect.
I’ve used US-05 enough to change those min/max values of the attenuation range so that the predictions are in line with my brews. FG is always right on now.

I don’t have enough brews with 1084 for that, yet.
I really liked it in an Irish Red. I kept it pretty cold though and plan that again; 64*F.


I can make 8 gallons of wort max.
I don’t want to top off and I hate going through all that work and not filling up the kegs.
Planning on brewing two 5 gallon batches and combining to homogenize before pitching.

Thanks again!

 

[TimmyWit]

Appreciate the inputs.

I can make 8 gallons of wort max.
I don’t want to top off and I hate going through all that work and not filling up the kegs.
Planning on brewing two 5 gallon batches and combining to homogenize before pitching.

Thanks again!

It is a lot of work but if you think about it, you can brew 8 gallons, split it and then your work will be cut in half at the cost of just 20% output. For your next brew, do 8 gallons again and now you will have 16 gallons from 2 brews instead of just 10. It's kinda like "brew 2 get 1 free".

Plus, since you're experimenting, if it doesn't work out, you haven't invested an entire brew day to the half you're not sure about so it's not nearly as much of a bummer. Once you get in the habit of brewing 8 gallon batches and splitting it, you won't look back. I have really been learning a lot by splitting batches and comparing them side by side.

 

[FunkedOut]

I ended up brewing a pair of 5.5 gallon batches. I already had the grains weighed and combined into the 2 batches.

First batch, I cooled using only tap water. I can only chill to about 90*F using tap water in FL. Then put in a keg and placed the keg into a 32*F freezer.
Next day, I brewed the second batch and again, chilled to about 90*F using tap water. Then poured the first batch, now at 32*F, into the boil kettle. Ran the pump for a good 10 minutes and got 11 gallons of homogenous 63*F wort
Saved myself the cooler with frozen water bottles and pump set up for both batches!

Anyway, for those that had any interest, OG of the split batch was 1.065, mashed at 157*F.
US-05 reached FG of 1.016 (6.5% ABV.
1084 reached FG of 1.019 (6.1% ABV).

Haven't had any taste tests yet. I'm giving the kegs a few weeks to finish carbing and come together.