Low alpha hops and great foam

[Miraculix]

Good evening.

I recently discovered that I am not the only one having made the discovery that the amount of hops being used is connected to foam stability. I am not talking about ibus here, but the total amount of hops. Dry hops or late additions or boil, does not seem to be that important at which stage they were added, the important thing seems to be the total amount.

So what is going on there? If I brew a beer with 20 Ibus with high alpha hops in the boil, I`ll be adding a small amount of hops, the foam will most likely not be that great. If I add the same amount of ibus via low alpha noble hops, the foam seems to be dramatically better. I also witnessed the same here with German/Slovak/Czek beers that are traditionally bittered with hops like saaz or similar vs. hop extract brews.

Same for dry hops, the more dry hops, the better the foam.

Anybody else made this experience?

I'll be using low alpha hops for my non-dry hopped or lower ibu beers from now on, just to get this extra foam boost.

Cheers!

M

 

[monkeymath]

I think hops are generally considered foam positive, but from what I could gather, this is often attributed to iso alpha acids - implying that it is, actually, about the IBUs.
Possibly there are other compounds as well that contribute to the foam stability. But the quantities of those might also depend on the hop variety used, so I don't think you can simply conclude "instead of 30g of hops X I am going to use 50g of hops Y, so I'll have more of whatever-makes-awesome-foam" at this point.

Moving away from IBUs in a similar way, you could also give your bittering addition a shorter time in the kettle, e.g. boiling the hops only for 30 minutes or so.

 

[Miraculix]

I think hops are generally considered foam positive, but from what I could gather, this is often attributed to iso alpha acids - implying that it is, actually, about the IBUs.
Possibly there are other compounds as well that contribute to the foam stability. But the quantities of those might also depend on the hop variety used, so I don't think you can simply conclude "instead of 30g of hops X I am going to use 50g of hops Y, so I'll have more of whatever-makes-awesome-foam" at this point.

Moving away from IBUs in a similar way, you could also give your bittering addition a shorter time in the kettle, e.g. boiling the hops only for 30 minutes or so.

Yes, that's what I've read to and I always bought that iso alphas are the foam positive part of the hops that actually matters.

But then, I've had beers with ibus from low alpha hops (big amount of hops) Vs the same beer, same ibus, with high alpha hops (low amount of hops) and the low alpha hop beer had far better foam. I've seen multiple beers where even dry hops increased the foam significantly, there couldn't be any isomerisation of the alphas.

I think there's something more to hops and foam that the current forum wisdom does not cover.

The shorter bittering time was also in my radar, that's probably a good idea.

I might try to do a little experiment with water on the weekend.

 

[Miraculix]

Nice one, I now found completely contradictory information about the effects of dry hops on foam. Scott janish quotes studies that show a detrimental effect after 2 days dry hopping time (I usually dry hop 3 days max) and other sources say that dry hopping generally increase foam.

Looks like there are factors involved that are not fully understood yet.

 

[AlexKay]

There’s an episode of the Master Brewers Podcast exclusively on hops and foam: Link. It covers a lot of bases, talks about foam-positive and foam-negative effects, and while the ultimate answer seems to be “it’s complicated” they do seem to understand a good bit of what’s going on. It’s a good listen.

 

[Miraculix]

There’s an episode of the Master Brewers Podcast exclusively on hops and foam: Link. It covers a lot of bases, talks about foam-positive and foam-negative effects, and while the ultimate answer seems to be “it’s complicated” they do seem to understand a good bit of what’s going on. It’s a good listen.

Thanks, I'll have a look!

 

[Miraculix]

That was interesting. So it looks like .... it depends

Certain hop types enhance foam when dry hopped, some do not, according to the podcast. All of them decrease the foam, if dry hopped longer than 3 days (this is also what Scott Janish was saying). They say that cascade is one of the worst foam enhancing hops, when dry hopped, but it worked pretty well for me in my last brew. I used 5g/l for 2,5 days dry hop duration and had really great foam.

Unfortunately, half of the talk was about marketing their foam enhancing products, which I am not interested in. I do not want to use additives in my beers. But it was very interesteing to hear how all these 10 ibu and below beers manage to get this weirdly strong foam, it is an additive.

Takeawy seems to be: dry hop 3 days max, better 2 days, certain varieties tend to enhance foam, certain tend to decrease it.

 

[Lefou]

Foam stability has been an interesting search for me, too.
My beers have typically been light-colored, low IBU ales because it suits my preference and water. I've always used packaged dry pellets and tended to adding wheat, but never dry hopped before bottling. One of my beers was a "starkbier" amber, brewed with extract and Saaz pellets, with an IBU level between 20-30. It had a ridiculous amount of thick foam that lasted, no matter what temperature it was served at.
One of my observations about foam in any beer, homebrew or commercial, is that foam is related to serving temperature. A Miller Lite poured at room temperature will foam differently than one served cold from the refrigerator. I've observed the same with a Founders porter as the foam was non-existent when the beer was cold, but very heavy and thick when served warm.
Conclusions? A well-carbonated beer is key, as is serving temp. Understanding the hopping might be beyond me.

I like foam and will sometime water down a low IBU commercial beer at room temperature by pouring over ice. The mug will foam over if you pour too fast. Same with the commercial, dry-hopped IPAs I like done with Motueka and Mosaic, but no ice for them, I like the heavy malt and hop balance. I've stopped struggling to understand the specifics and have gone with what I see.