2 replies to this topic

[Genesee Ted]

I will have a lot of hops on my hands at harvest and have been toying with trying to make an extract from them for late addition/dry hop character. Or for anything for that matter. I have tried to do some looking around but havent been successful thus far in finding any info on DIY production for a brewing application. Has anyone any info regarding this interesting substance?

[BrewerGeorge]

I tried to extract the goodness from a full ounce of hops with vodka a few years ago. It produced one of the vilest things I've ever tasted. There was nothing good whatsoever about it. Bitter beyond all description along with a capcasin-like heat. The taste stays with you for hours. Actually, I still have it in the freezer, and it's a running bet that I'll give $10 to anybody who can do a second shot.Commercial hop extracts are made with serious chemical solvents or, IMO, with liquid CO2 as the solvent. Basically, the processes are out of our reach as DIYers.

[chuck_d]

doobah... I saw this thread when I was down in DC and it stuck with me as I wanted to look up what I had read in the practical handbooks about the processes, but instead was reminded of your thread when I got to the discussion of extract production in Kunze. I'll try to paraphrase them both...CO2 extraction is what is more commonly used, ethanol extraction is less specific (extracting a wider range of hop compounds) but it also does not require pelletization like CO2 extraction does. CO2 extraction is totally not within the scope of the homebrewer as pressures ranging from 1,070 to 5,000 PSI are used, but the fact that pelletization is required already scratches it from your options with your homegrown hops.So... ethanol extraction...Some of the things that are extracted by ethanol and not so much with CO2 which will end up in your extract include fats and waxes (depending on the CO2 method) pigmented compounds, oxidized compounds, polyphenols and metals. Extracts will remain variety true, and carry the varietal characteristics of the hops from which they are made though commercially they usually made from high alpha varieties.Sidenote: The chemical solvents that were previously used in the production of hops extracts, such as methylene chloride and hexane, are no longer use due to concerns of residual solvent remaining in the product.The ethanol extraction process goes something like this. A 90% ethanol solution are mixed, then the hops are wet milled and put through a countercurrent extractor (where the ethanol flows in the opposite direction of the hops). The miscella (the resulting alcohol solution containing the extract) is concentrated via evaporation and then further reduced through some sort of steam wash (done in a vacuum so that a low 60*C temp can be used).It's worth noting that this is not isomerized extract (although there is some isomerization) and it is not light stable. I'm not sure if the evaporation step is considered a distillation process, and so I don't know if it's legal to do at home. Technically you're not producing alcohol but restoring it back to how it was in an effort to leave behind the hops compounds, but seriously I have no clue about legality since it might be operating a still. If there is a legal way to evaporate the ethanol off of the extract, I would probably do a short soak of the hops in ethanol, then blend them up perhaps, then transfer to a container which I then top off with ethanol to remove all the air. Then maybe stirplate it, put it on a hot dog roller or something like that, finally followed by trying to evaporate off the ethanol (if legal). Maybe instead of blending, if you've got a mill and can adjust gap way down you could wet mill your hops. To avoid the questionable legal area of ethanol evaporation, you could probably just then use only as much ethanol as is needed to cover the milled hops and an appropriately sized container for agitation. Then strain the hops out, brew a low alcohol high bodied beer and dose it and see what happens.