Hop Pollination

[Apimyces]

So... when exactly do female flowers get pollinated, and when do seeds form? Should one be able to feel the seeds by pressing a ripe cone between one's finger?

What's the protocol to collect pollen for manual fertilization?

I've got a male by my females, but I'm starting to doubt if he did his job properly. Not noticing any seeds yet.

 

[Apimyces]

So... when exactly do female flowers get pollinated, and when do seeds form? Should one be able to feel the seeds by pressing a ripe cone between one's finger?

What's the protocol to collect pollen for manual fertilization?

I've got a male by my females, but I'm starting to doubt if he did his job properly. Not noticing any seeds yet.

Also, for the male haters:

http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1976.tb03720.x/epdf

Hops yield more, not only in terms of dry weight per cone, but also in terms of alpha acids per acre, when pollinated.

:fro:

 

[GVH_Dan]

male haters...I won't even bring up the age of your research paper of the prevailing theories at the time and simply ask, where did you get your male? Is it a true male or a hermaphodite? The hermapodites are females that will sprout male when under stress but are often (not always) sterile. If he did...produce...you would have seen a white dust.

If your cones are with seed, they are inside the cones near the lupulin glands.

 

[Apimyces]

And here I thought science was ageless. Darn, must be frustrating to have to calculate at what temperatures water boils and freezes every 20 years.

Theories evolve. But facts? Are you telling me that pollinated hops yield less today thean then...?

A male is a male. A female with pollen sacs is not a male. Let's not start the 52 genders of hops.

I know where the seeds are when mature, what I don't know is when they start to grow and mature.

 

[GVH_Dan]

First, sorry I read "when" as "where".

I would suggest you spend sometime reading this thread for your answers: https://www.homebrewtalk.com/showthread.php?t=397219

I also apologize if I offended. My question wasn't a stab at your intelligence, but a valid one based on typical questions regarding "males" that are posted on this forum. I was simply wondering if you had a true male or something else that wouldn't produce pollen.

As far as science being ageless, true, but so is the process of researcher's bias influencing the results. Look at research into the optimal drying temperature of hops:

1891 - 86F ,Tommes
1938 - 104F, Zazvorkz-Zima
1958 - 104F, Kunz-Skladal
1963 - 140F, Bailey
2003 - 149F, Roßbauer​

So what happened between 1958 and 1963 to radically change "optimal"...it was what they were optimizing for. Prior to 1960, they were thinking optimal quality. After that, it was economic optimization because big beer was asking for alpha's instead of oils. Alpha start to break down at 140F so that became the new optimum.

Now back to your paper. If you read the history of growing hops, it was traditional in Kent and elsewhere in Europe to plant males at the corners of the field to pollinate because that was the "best". It was in the US that some experimented with non-pollinated hops and decided they liked the flavor and stability in brewing chemistry better. 40+ years ago, the old world-new world battle over the proper way to grow hops was being waged and you kind of have to question what the bias of the researcher was at that time.

I'm not trying to blast you or anything. I'm just saying the history of growing hops has not been a straight line, consistent method nor has the definition of a "desirable" hop been consistent. I had a neighbor who's grandfather used to dry his hops by wrapping them in straw and warming them with composting horse manure to get the flavor he wanted. Not something I would care for but that was desirable back then. Or check out some of the growing manuals from the late 1800's where the research insisted that the hops needed to be tied to a pole using RED wool thread.

Anyway, one other question. Why focus on alpha anyway? There are plenty of high producing alpha hops out there. You don't need to try to enhance the alpha levels of your hops. Anyone can buy alpha. Most of the research today is and the holy grail is finding a new aroma hop that gives a beer a new and interesting flavor.

 

[B-Hoppy]

So... when exactly do female flowers get pollinated, and when do seeds form? Should one be able to feel the seeds by pressing a ripe cone between one's finger?

What's the protocol to collect pollen for manual fertilization?

I've got a male by my females, but I'm starting to doubt if he did his job properly. Not noticing any seeds yet.

The females are receptive to pollen when they are in burr.

What I've seen done is that the breeders will sometimes place some sort of plastic bag over the entire male sidearm once the inflorescence are opening up to discharge the pollen. This can be kept refrigerated for a length of time, don't know how long it will stay viable.

 

[nagmay]

And here I thought science was ageless ... Theories evolve. But facts? ... A male is a male. A female with pollen sacs is not a male.

I can't tell if you are trying to be sarcastic/funny - but I find that core sentiment is deeply misguided. The entire point of science is to test new theories and constantly reevaluate "facts".

Personally, I have produced viable seeds with pollen derived from a female hops plant - something that I was told (many times) could not be done. Like most organisms, the sex of hops is much more fluid than previously documented.

Others in this thread have already addressed your pollination questions, but I will say - having brewed with seeded hops - that I prefer my cones "sensimilla".

 

[PapaBearJay]

The females are receptive to pollen when they are in burr.



What I've seen done is that the breeders will sometimes place some sort of plastic bag over the entire male sidearm once the inflorescence are opening up to discharge the pollen. This can be kept refrigerated for a length of time, don't know how long it will stay viable.

Bob is right, the hops are receptive during burr. If the pistils have begun turning brown, you're too late.

The best method for storing hop pollen is in a low moisture environment (dessicator) under liquid nitrogen, but since LN is hard to come by for most people, refrigerated or in a freezer will do.

 

[Apimyces]

Thanks. I've only got a few minutes so I won't be replying to all.

My point about science was sincere, though obviously such a short statement can easily me misinterpreted. Science is about repeatability. What is "best" is arbitrary, and thus evolves through time. If you cannot mimic a trial at a later date and obtain the same results, then there was a flaw in the methodology. Which, of course, happens. Learning boiling temperature, for example, starts by taking it and changing the temperature until you see the phase change. Then, later, you start toying with other variables, like air pressure, to see how it influences your findings. But in the end, bringing the liquid to the exact same conditions as in the first trial should yield the exact same results. If it doesn't, either there was an error in the original methodology, or, more likely, there is another variable that wasn't controlled and that differed between the two trials.

So, what could have changed since those trials in the UK? Maybe new varieties, though we still use a lot of the old ones. Pollination impact could very well be influenced by genetics. Maybe different weather has different effects. Could be a bunch of variables that would skew the results. But if you took the same varieties and redid the trial at the same places, you should get the same yield increase via pollination.

 

[Apimyces]

I think my boy failed his job, though. Lifting up some of those cone's skirts I'm not seeing any seeds... Got a fair number of cones, though, maybe I'll get a few anyways. Will have to reconsider my hop "yard" layout for next year.

 

[Apimyces]

Bob is right, the hops are receptive during burr. If the pistils have begun turning brown, you're too late.

The best method for storing hop pollen is in a low moisture environment (dessicator) under liquid nitrogen, but since LN is hard to come by for most people, refrigerated or in a freezer will do.

I've got a dewar, but bought on the cheap on ebay. Doesn't keep LN for very long. I typically only buy it once per year, in Spring.

I think my male is done throwing his junk around for the year. All those flowers look wilted now, no new ones in sight.

 

[GVH_Dan]

So, what could have changed since those trials in the UK?

I'm not a chemist, but I know the ASBC Methods of Analysis is on its 14th edition. I'm quite certain the method used today is not the same as in the 1970's. And as I stated before, there was a significant bias on that side of the Atlantic to show pollinated hops were better.

Maybe new varieties, though we still use a lot of the old ones. Pollination impact could very well be influenced by genetics. Maybe different weather has different effects. Could be a bunch of variables that would skew the results. But if you took the same varieties and redid the trial at the same places, you should get the same yield increase via pollination.

Probably not. I can (and have) tested hops from one side of our 25 acre field vs. the other side vs. hops from another field 40 miles north vs. another field 50 miles east, etc. and obtained different results. The all follow the same growing procedure but obtain different results. I've heard the same from the big growers out west. Unless a pollinated an unpollinated plant were grown side by side, I would find it hard to believe the results.

For the record, I'm an engineer, not a horticulturalist or chemist, so I'll defer to PBJ and Nagmay's opinions on the subject.
For the record, I'm not a chemist or a horticulturalist. I'm an engineer but I've run a fair number of these tests

 

[Northern_Brewer]

Here's a paper from Switzerland on brewing with seeded hops :

J. lnst. Brew., September-October, 1978, Vol. 84, pp. 276-7
EFFECTS OF PRODUCTS FROM SEEDLESS AND SEEDED HOPS ON BEER QUALITY
By H. B. Pfenninger and H. Hug (Swiss Brewing Research Station) R. G. Ault {Hops Marketing Board) and R. M. J. Kenber (Lupofresh Ltd.)
Comparative semi-industrial brewing trials with standard Continental lager beers have been carried out in Switzerland using hop pellets and hop extracts made from seeded and seedless hops. It has been demonstrated that the products from seeded hops containing 8% and 9% of seeds have no adverse effect on beer quality and that the flavour of all the beers was acceptable.

 

[Apimyces]

Yea, I've read that article (or a similar one) in the past.

Main risks with seeded hops, from what I recall, is too much seed oil going rancid. That's probably more of a risk with prolonged storage though.

For the research bias, I'm not sure I see it. The article was done when the UK market was opening up. The point of the study was to determine how british growers should adjust their production to face this opening market, and whether switching to seedless production for exports was a good idea. It has nothing to do with convincing brewers to use seeded hops. Fudging their results to obtain a wrong result would be detrimental to UK growers.

If the Swiss paper had been done in the UK, THEN, sure, potential bias would put its credibility in question. But fudging a trial in order to intentionally get "yields are better with pollination than without it", if it's untrue, would not benefit UK growers in any way.

Questioning the validity of a trial's findings is part of the scientific progress, but to immediately jump to "it's old, therefore it's false" is quite a leap. Are there any published trials that report contradictory findings?