Inconsistent Roast/Dark malt flavor contributions

[MrMeans]

Several times now I have brewed the same recipe without any changes, yet I have noticed the flavor contributions of my dark malts varies. My mash temps have not changed by more than 2 degrees F, I have kept my mashing and sparging techniques consistent along with boil times and hop additions. I have no changed my mineral additions and have been using the same source for water (commercial RO from the same store). My grains have come from the same shop. All of my brewday numbers are consistent, I would not say identical but I think that 2 or 3 gravity points would not be the smoking gun here.

I am out of ideas on the cause for this variance amongst my brews. Any ideas on how to improve utilization and flavor contributions from dark malts, or just make them more consistent?

 

[Zepth]

My only guess would be what if anything happens to the grains before you get a hold of them. I know my LHBS repacks briess, weyermann, Canada malting into their 1/4 1/2 and 1 kg bags for those who don't want to buy a 55 lb bag of black patent or chocolate. Is it possible that yours is doing the same, and if so could they possible switch between maltsters due to pricing/ supply issues?

 

[chickypad]

It sounds like you've already ruled out the two thoughts I had, which would be differences in water chemistry or maltster. What is inconsistent exactly, the degree of roast/flavor you are getting or different flavor in general? Were the fermentation and aging procedures/temps/times the same?

Edit: simultaneous post, actually Zepth has a good point. You said same LHBS but is it for sure the same maltster? I've had the experience before with noticeable differences between brands of chocolate and coffee malts for example.

 

[MrMeans]

The flavor contributions from the malts are what is inconsistent. Temperatures are kept at 19.2 C for the first 5-7 days then allow it to rise to 20.8 C to clean up for another 7 days before bottling. I have a fermentation chamber I made from a mini fridge and a pretty accurate temp controller. Those are the ambient temps inside of the chamber.

I guess it could be possible that they are using different maltsters at my LHBS. I try to make a note of if I am using English/Canadian/American malts so if something significant happens I will have note of it. I will usually go with English roasted malts because I feel they are a little smoother and less astringent than the American malts.

There was one batch that I used an Irish ale yeast instead of my standard 1056/WLP90. I do not remember anything significant with that batch other than getting krausen in my airlock from an EXTREMELY vigorous fermentation. It was more on the dark roast forward side of things but I would say I had a comparable malt character in batches using WLP90.

Here is my recipe if that helps, its a cluster**** of malts.

Malts Mashed Amount
2 Row 8
CaraPils 1
Black Barley 0.5
Chocolate 0.5
Crystal 40 0.5
Crystal 80 0.5
Roast Barley 0.5
Oats (flaked) 0.5

1 oz magnum 13% AA 60 minutes

Mash at 152 for 60 minutes, batch sparge

4 g Gypsum
6 g CaCl2
2 g NaCl

This is for 6 gallons going into the fermentor, I usually aim to leave .5 gal in the kettle with the break material and hop sludge, and .5 in the fermentor when racking off to bottle.

 

[tootal]

The only thing, other than what's been mentioned, is ph. I see you're doing water chemistry but what is your initial ph? If I remember correctly, dark malts tend to lower the mash ph more than base malts. Are you treating your sparge water too! Just brain storming here.

 

[MrMeans]

I do not have a pH meter yet. By my math I am coming in around 5.3. I do use the five star buffer stuff that I hear mixed results about.

 

[IL1kebeer]

Are you getting your roasted malts from the same manufacturer? Different malts, especially roasted malts, vary greatly between maltsters.

For example:

Simpsons Chocolate: 375L-450L
Briess Chocolate: 350L
Hugh Baird Chocolate: 450L-550L

This makes a huge difference since the time and temperature that the malts are roasted directly affects it's flavor, and as you can see the same malt between maltsters vary from 350L-550L, which is huge. A 350L chocolate malt is not going to have nearly the same flavor as a 550L chocolate malt. All of this is also true for roasted barley and other dark malts.

I'd check with your vendor to see if they always carry the same malt to fulfill their orders or if they substitute based on availability.