Category Archives: Yeast

Yeast Slants

Slant City

This bank holiday evening I finally got around to slanting some yeast that had I sat aside in the fridge. My normal practice when I get a new yeast vial is to pitch all but a few ml, that’s all I need to create a few slants. Tonight I slanted yeast for Wit, Saison, Belgian Abbey, California Ale,  ‘Denny’s Favourite 50’ and Czech Budojevice Lager.  Let’s hope they all take!


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Yeast Ranching: storing yeast on slants

“Rollin’ rollin’ rollin’, keep those yeasties rollin’… don’t try to understand em…”  etc.

Yeast slants

Storing yeast on slants is a handy way to keep a ‘bank’ of liquid yeast strains in your fridge that will keep for months and months. The basic idea is this- you make a jelly from malt extract and something to make it set, either agar or gelatine, you put some in a vial, sterilise the whole thing with steam, let it set almost horizontally so you get a larger area, and finally swab it with a source of yeast, like a vial of liquid yeast or a previous slant. Within a few days the yeast will grow on top of the jelly, and you can stick the whole thing in the fridge. To revive it, simply mix some weak wort like you would for a normal starter, put some in the vial, shake it to dislodge the yeast (or scrape it with a sanitised implement if necessary), and add it to the half pint of wort you’ve made, and build from there.

Malt extract from the health food store, and agar agar from the Asia Market

There are other more technical posts on yeast ranching, but here’s how I do it. I add 10g of agar agar to 250ml of wort. Agar agar is available in shops that sell a lot of Asian ingredients. I got mine in the Asia Market on Drury St. in Dublin. Beware- when I went in first the only stuff I could see was in the Japanese aisle, and it came in either red, or green- it was clearly dyed in order to make some hideous dessert. The slants I made with it didn’t work, green dye ran everywhere. In one of the Chinese aisles though, I found the clear, uncoloured stuff. It’s made from red algae, and it looks like scrunched up cellophane.

Dissolving agar in the wort

You have to heat the wort and add the agar gradually, until it has all dissolved. This took a while, maybe 10 or 15 minutes. Unlike with gelatine, it doesn’t really matter if it hits the boil now and then. It was hard to find good information on ratios, but 10g/250ml made quite a well set jelly, you could probably get away with less.

When it had all dissolved, I added it to 10 or so vials. I used vials I got from a fellow homebrewer, Shane, who got them from some scientific supply place. They are handy because they are large, but also have a flat bottom, and they’re made from a resin that can withstand high temperatures. This means I can stand them in my pressure cooker. Real scientists

Fill them to between 1/4 and 1/2 full

use a thing called an autoclave to sterilise with steam, but it’s essentially a big pressure cooker with more bells and whistles on. Steam sterilises, and the higher pressure the steam is at, the faster it does it. I popped everything in the pressure cooker for about 15-20 minutes, with the lids lightly on the vials.

When that was done, I screwed the caps on, and I laid the vials on their side, so that the jelly came almost to the lid. This means we have a surface area that is a diagonal cross section of the tube, that is, quite a nice little area for the yeast to grow. Popping everything in the fridge at this stage speeds up the setting.

When it’s all set, it’s time to inoculate the slants with yeast. If you can find an

Sterilisation by steam

inoculation loop in a scientific store or on ebay that’s great, I made one by twisting a guitar wire so it had a loop about 2mm wide on the end. I had sterilised this loop in with all the rest of the  gear in the pressure cooker. The loop picks up the yeast on the end. It’s not necessary to have it dripping with the liquid yeast, a small amount of cells will grow up to be colonies of millions.

Old slant containing yeast growth on the right, fresh slant on the left

For the next stage it’s crucial that everything is super clean, because this is when the sterile slants get open, and there is the risk of exposure to something other than yeast. Make sure hands are sanitised, and surfaces, and if possible work beside a flame, as this means the air above where you’re working is less likely to have any nasties in it. I do this step in my kitchen beside the gas cooker with one ring on.

Each time you dip the loop in the original yeast, you need to sterilise it. You can do this by holding it in the flame for a few seconds. I cool it then by dipping it in a glass of starsan. Some people recommend touching the hot loop off the inside of the vial to make sure it’s not still hot as this will kill your yeast. Dip the vial in the yeast, and then quickly remove the slant’s cap, swab it from the end to the entrance in a zigzag motion, and replace the cap. Sanitise your loop, and repeat with all your other slants. That’s it, you just leave them out somewhere and in a few days you’ll notice a nice creamy coloured growth where you swabbed, that’s the yeast. A week later you can pop them in the fridge for storage. By this time, if any are bad, you’ll notice. It has happened once or twice that I got some blue mould growing in my slant, so it’s always a good idea to do more than you need in case this happens.

After 5 days or so, healthy white yeast growth is visible!

You can then grow up a fresh, 1st generation yeast whenever you need it, and if you fear that your slants have been in the fridge a little too long, you can always use an old slant to inoculate a new slant, as I did in this case. Instead of dipping your loop in the liquid, you just scrape it on some of the yeast in the old slant.

Tip: When you buy a liquid yeast vial from Whitelabs or whoever, leave a few ml of liquid in the vial when you pitch to your beer, and pop it back in the fridge. This will be enough to make slants with at a later date.

Other resources:

I cannot recommend Yeast by Chris White (of Whitelabs) and Jamil Zainasheff highly enough. Get it if you’re interested in yeast and how to handle it properly.

There are lots of other online guides to making slants such as


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Trappist Technique: Belgian Sugar

For now we see as through a glass, darkly

Recently one of my viewers asked me how my Rochefort style beer Rochefortesque was getting on, now that it has aged a bit, and whether I would do anything different. As luck would have it, a couple of weeks ago I had another go at a big Trappist beer again, and yes, I did try something new out. As to Rochefortesque, it seems to be thining out slightly, and as I said at the time, I would have preferred it to have a little more of the ‘rummy’ character in a real Trappist. Hopefully the following will address those defects

Big Trappist style beers are the dark, rummy strong beers that a number of Cistercian Monasteries brew in Belgium (also a German and one in Holland). I thought I’d use White Labs number 530 yeast, which is supposedly derived from Westmalle’s yeast strain. So far so good. But what I decided to do differently this time as opposed to my last Trappist style beer was use some homemade caramelised sugar for colour and flavour. As you can see from the recipe below I only used a very small amount of black malt for some extra colour, and I used some dark crystal malt to give me a good caramel sugar flavour. I used the same amount by weight of sugar. The method I used to darken this sugar was simple. I simply heated it in a pan along with some citric acid, and slowly it went a cream colour, then a bit yellow, and it began to clump together and finally it liquified. Then it was a matter of boiling it gently until it didn’t seem to be getting darker any longer. I could have boiled it for a shorter time if this had been a different type of beer, and I could have achieved a nice amber colouring, but for something like this I wanted maximum colour and flavour from the caramelised sugar. My inspiration here, as always with brewing Belgians is Stan Hieronymous, whose books I can’t recommend highly enough. The recipe site also documents the process of boiling sugar with acid, the point of which is to ‘invert’ it, which means the sucrose breaks down in to fructose and glucose, by a process apparently known as ‘hydrolysis’. The point is, they are easier for the yeast to eat than sucrose is. Here are some pics of the process. click for bigger versions.

Sugar begins to clump together, keep stirring it!

Almost all the sugar has started to liquify

At this stage it is darkening

Pour in to a foil-lined tray, it will harden and cool. Remove from foil and break it in to pieces when it has cooled

This beer turned out Big. I used 7KG Pilsner Malt, 500G dark Crystal Malt, 500G Caramelised Sugar, and 60G Black Malt for 20L. The original gravity was 1.116! It finally finished at 1.026, which gives it a whopping 12% ABV. I hopped with Northern Brewer at the start of the boil, Hallertauer at 10 minutes, and Styrian Goldings at the end, for an IBU of 40. You really don’t taste it though since the final gravity is so high.  It is quite sweet, and what I like most about this sugar method for darkening the beer is that, while it sits in a chalice style glass it looks very dark, but it is very clear upon inspection, with a beautiful ruby colour. I said above that it finally finished; this was a troublesome brew. Although I made up a decent sized starter,  I clearly didn’t pitch enough yeast, and for one of the few times in my brewing life I had a properly stuck fermentation. I pitched a load of s05 from a pale ale fermentation, and that sorted it out. It still has the characteristic Belgian yeast flavour because, even though it stuck at about 1.050 it had started at 1.116, so the WLP 530 had ample chance to do its thing! In any case, s05 is well known for being a fairly neutral yeast. I thought I knew this lesson already, but the moral of the story is Caveat Cervesarius! Don’t underpitch with a beer this big.

Colour inspection


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Three Men and a Little Barrel

Decommissioning the barrel at an undisclosed location in Naas, Southern Eire.

Finally, closure on our Epic project. A little over a month ago, Kev, Peter and I gathered in Naas to bring forth the fruits of our labour, the beer that we now call Diogenes, and described in several previous previous posts . After a gestation period of about 4 months, we each filled two 20L containers to bottle at our leisure, and we bottled the remaining 50L or so there and then, on a freezing day in January.

Diogenes finished at an Epic 11.5% ABV, which means it attenuated even further in the barrel, gaining an extra point ABV since it went in. Tasting it, we were very excited. Obviously putting something in a wooden barrel and leaving it you take your chances, but there was not a hint of funk about the beer. Tasting it alongside a pre-barrel bottle you could discern a real smoothness about it, the angular, almost rough taste points in the pre-barrel beer, the harsh roastiness from the excessive amount of black malt had all vanished. The whiskey was obvious. The oak’s vanilla was a beautiful accompaniment to the imperial stout flavours, and of course in the glass it is a thing of beauty, thick and black and velvet, it stains the glass brown as you swirl it up the sides.  We all agreed (to unashamedly blow our own trumpets) that this may be one of the best beers we have tasted, let alone brewed.

With a beer that clocks in that high, we decided we’d need to reseed the yeast, that is, introduce new yeast at bottling time in case the yeast already in the beer had either dropped out of suspension (perfectly possible after 4 months in the freezing cold), or else had just plain died due to the high alcohol content. If this happened, it would not be possible to bottle condition the beer (i.e. carbonate it), and so it would be flat. We reseeded 2 packets of safale s05 dry yeast for the 50l we bottled on the day, which is a high reseed level, I estimated it was over 3 million cells per ml. It is common practice for the stronger belgian beers to be reseeded at bottling time for this same reason, and 3m cells per ml is on the higher end of the scale, so when I came to bottle my own portion I used considerably less, which seems to have worked nicely. We didn’t want too much carbonation for this beer, as the almost syrupy black consistency is rather pleasant when undercarbonated. I bottled the majority of the beer in small bottles, and a number of them in large bottles which I corked, and I intend to keep for some time. I wasn’t one to muck around with the final product, being a purist, but Kev, who thinks he must be an Irish Sam Calagione or something decided to steep some of his on raspberries, and he says it’s great, but I haven’t had any yet *hint hint*.

We’re so happy to have seen this project through, and even happier that all our effort paid off so well. Everyone who has tasted this beer loves it, and it was a big hit with the other homebrewers at the Beoir January tasting session at the Bull and Castle pub in Dublin. It’s the end of a great adventure, and the only question is, what goes in the barrel next? Answers on a postcard please.


Filed under Beer, The Barrel Project, Yeast

Brewing a “Black IPA”

A wonderful new oxymoron from our American cousins, but as Ron Pattinson pointed out last year this ‘innovation’ was already brewed by the brewers at Burton, home of hoppy IPAs at least as early as 1888. The passage from the old brewing book that Pattinson pulls out hits the nail on the head as to what this ‘new’ style is supposed to bring us, basically it will look beautiful and black like a stout, but it will taste like an IPA. Faulkner in “The theory and practice of modern brewing” says

while I can example this by referring to the black beer produced at Burton, which has been universally described as a mere black pale ale—i.e., though black in colour, its palate taste reminds one very strongly of the pale beers produced by Burton firms.

The Grain Bill: Pale, Crystal and Carafa

He is not a fan. But Kev and I were intrigued enough to give one a go. The style that the Great American Beer Festival recognise as “Cascadian Dark Ale”, “India Black Ale” or “Black IPA” seems like a bit of fun. But why is this not just a heavily hopped stout or Porter? Well the key is to get the thing black without giving it a burnt or coffee bitter roast character that a stout might have. The key to this is to use dark caramel malts like dark crystal, and “Carafa®”, a proprietary malt from Weyermann. Carafa is de husked roasted malt, and by removing the husks you remove a lot of the bitterness. Of course the Continental Europeans have long been at this, i.e. brewing black beers (schwarzbier) which taste just like lagers, that is they do not have the roasted character, but they are very dark brown or black. Faulkner in the cited passage basically says this about the Burton example: ‘it might be ok for the euro-types, but it’s not what I expect from a stout”

It will be quite understood that I am not decrying this article; it may and does suit many palate tastes, and is thought a great deal of on the Continent, but at the same time it differs very widely from the accepted standard quality of a black beer as specified

Plenty of Hops

So basically the point was to make an IPA, but add some Carafa malt to turn it black. Here’s what we came up with:

“Black IPA” : 40L : Mash Efficiency 86% : OG 1.076 : ABV 7.2% : 78 IBU : 34 SRM

Grains: 9KG Pale Malt, 1KG Munich, 750G Crystal (55l), 750G Crystal (150l), 500G Carafa® III

Hops: 60 mins: 65G Magnum, 20 mins: 40G Chinook,40G Cascade, 5 mins: 25G Chinook, 30G Cascade, End of Boil: 40G Amarillo, 20G Chinook, Dry Hop: 100G Citra

Yeast: Wyeast West Yorkshire (1469 PC)

We mashed at 66c for 60 minutes, and sparged with 80c water. We treated the water roughly for the “porter” profile on the following calculator with some

Recirculating the mash: Don't disturb the grain bed!

CRS and some Calcium Chloride. We used a mixture of Bairds Maris Otter and Weyermann Pale Ale Malt as the base malt. We are accustomed at this stage to using Magnum as a nice clean bittering hop, and as for the rest, we thought that the sweetness of Cascade would be tempered by Chinook, which I regard as a bit of a ‘rough’ flavour, but rough in a good way. I think Stone brewing Co. use a lot of Chinook in their IPAs, and I once made an all Chinook IPA that was one of my favourites. Amarillo has to my mind a more pleasant aroma to Cascade, so we stuck it in at the knockout. As far as the Citra goes, well, we were already brewing the latest fad from America so Citra, a proprietary hop recently developed for Sierra Nevada (and the talk of the town, where that town is exclusively populated by hopheads) seemed apt. It is used as a dry hop in their beautiful “Torpedo”, in fact it is dry-hopped using the device of the same name, a vessel that is filled with hops while the already fermented beer is pumped through it repeatedly to strip every ounce of flavour from them. I’m really looking forward to it, it is supposed to be very similar to Amarillo, on the orangey side of citrus.

In fact, we realised half way through the brew that we were brewing very trendy; combining the hop-du-jour, Citra, and the latest style from the Pacific Northwest. The July-August edition of Brew Your Own magazine devoted an article to it, “Birth of a Style: Cascadian Dark Ale”. As Kev leafed through it he looked at me, horrified, and said “Do you realise that we’re really brewing to style  here?”, as the article waxed lyrical about the “unexpected flavours” revealed by the interaction between the classic Northwestern hops like Cascade and Amarillo, and the debittered dark malts. I’m looking forward to those!

We mashed a total of 12KG, which is about as much as my mash tun can handle, though I have noticed that my efficiency rockets when I brew this amount.

The blue one is dead. The rest are healthy, but they are very sad. This is like a little yeast funeral.

Last weekend Peter and I brewed a clone of Goose Island IPA (recipe to follow shortly) and my efficiency was up towards 80%. For the Black IPA I calculated it as 86%, which I imagine is down to the increased grain bed depth, I have read that correct grain bed depth is important to efficiency. I recirculated 2L as usual, we ran it off, and had to sparge twice for about 44L pre-boil volume. I added about 2 or 3L extra during the boil to keep it topped up, and I had enough to make a 5L batch of 2nd runnings at about 1.045 OG.

Lately, inspired by Chris White (of Whitelabs) and Jamil Zainasheff’s wonderful book Yeast, I got the old microscope down out of the attic. I had a starter on the go of West Yorkshire yeast from Wyeast, and so I plated up a diluted sample of it, and I added the pigment “methylene blue”, which is used to check the vitality of your yeast cells. The dead cells stain blue, because they cannot metabolise the dye. I’m still waiting for my Hemocytometer to arrive in the post, it’s basically a microscope slide that

Because this beer was such a great idea we decided to ferment it in a giant lightbulb that Kev found.

has a tiny grid etched on it, so you can do a yeast count, and estimate upwards based on how many cells there are in a microscopic square, to how many millions of cells there are per ml. But at least this showed me that very few of my cells were dead, and so the yeast was healthy. It was surprisingly easy to take a picture, I just held the camera up to the eyepiece and twirled the knob until it was in focus.

Our Black IPA is fermenting away strongly now, and as soon as it gets near the final gravity I plan to introduce it to 100G Citra, and they can have a little chat about who is trendier.

Happily fermenting away


Filed under Beer, Hops, Recipe, Uncategorized, Yeast

Ring Out, Solstice Bells!

A quick recipe post today, in the window of opportunity between christmas presents and overeating. This year’s christmas beer is called simply “Solstice”, in honour of my favourite christmas song, the only non-christian one I know; “Ring Out Solstice Bells” by the glorious Jethro Tull. “Seven maids dance in seven time”. Indeed.

Skerries Covered in Ice

Skerries, like most of the rest of the country has been under ice and snow for weeks now, and the lowest temperatures in decades are being recorded, as low as -19c in some places. Skerries hasn’t dropped much below -8 at worst, but it’s colder than I’ve ever known. I’m on constant freeze watch for my beer in the shed. As long as it doesn’t freeze this is excellent lagering weather.

Which leads me to a feature of Solstice. I used some repitched Wyeast 2124, “Bohemian Lager” Yeast. The Wyeast site says it can be fermented at a higher temperature, the usual 18-22c ale range, to achieve a type of common beer, which I discuss elsewhere. However I couldn’t find any mention of this on the Megabrain, so I decided to experiment. My beer fermented vigorously at about 17c, and produced the most solid head of foam I have ever seen, solid and thick, and in weird swirling formations. It smelled a little sulphurous for a day or two, as lager yeast can, but it ended up very clean, and with no off flavours such as fruity esters you might be worried about. All in all I can recommend this yeast as a good clean yeast that you can ferment indoors during winter temperatures, and then lager outside.

I started late with this beer, it was only brewed on December 1st, and 10 days later fermentation was well finished. It was so clear when I sampled it out of the fermenter that I’m surprised it’s still pouring a little cloudy from the keg. It could be that it’s so cold in the porch that chill haze is a factor. It is quite a dark beer with amber notes when held to the light. The head retention is good. It is basically in the style of a continental brown beer, it tastes lagerlike, but with a good sugary whack from the crystal used for colour. My initial inspiration came from some of the festive beers I sampled in belgium at the end of November, in particular a spiced offering from Senne I think.


As a festive beer this is hopped low, and spiced high. I used Ginger, Nutmeg, and just one Star Anise. I tried to be subtle, but I would definitely add less ginger next time, it sweetens the brew and dominates the other spices. I aimed, and achieved 6% abv, which is a proper level for a festive beer I think. The aroma is also dominated by ginger.

Half a Pint of Solstice Please!

Here is my recipe

“Solstice” :  25L : OG 1.056 : FG 1.011 : 6% ABV : IBU 40 : SRM 17

Grains: UK Pils (2.5 KG), Munich Malt (2.5 KG), Wheat Malt (.5 KG), Crystal 55L (.5 KG), Roast Barley (.15 KG), Acid Malt (.1 KG)  Mashed at 67c for 70 mins

Hops: Magnum (25g, 90 mins) Cascade (25g 10 mins)

Spices: 1 x Star Anise, crushed, 1 Heaped tsp Nutmeg, 1 heaped tsp finely grated Ginger (Added to boil for final 5 minutes)

Wyeast 2124 “Bohemian Lager”, repitched, 200ml

1 tsp Calcium Chloride.


Happy Christmas everyone!


Filed under Beer, Recipe, Yeast

Cantillon Brewday

Old Bottles on an Old Bottler

Each november, and also sometime in spring, the Cantillon brewery, which is also a designated museum throws open its doors for a day, so that hoardes of geeks can flood in, and ‘oooh’ and ‘aaah’ over mash tuns, bubbling barrels, coolships and cobwebs. I visited them once before, but they weren’t brewing. It was still great fun to wander around and check the place out, but this time it was a lot more fun. Cantillon is unlike other breweries, as it only brews ‘lambic’ or spontaneously fermented beer. They don’t add extra yeast. More about that later.
The brewday starts early, and so at about 6am, Kev and I found ourselves traipsing down Anspachlaan towards Anderlecht with an appropriate lack of spring in our step. It pissed rain all weekend. Brasserie Cantillon looks just like a normal building on a suburban 19th century Anderlecht street, from the outside you could have no inkling what magic lies inside.

The place was already a hive of activity even at that early hour. People huddled with coffee and croissants, and a little stove in the tasting area was burning away. We latched on to one of the tours that were going at regular intervals, and made our way in to a room that contained a mash tun, with magnificent rotating stirring arms plughing their way through the turbid mash, which was in the process of being doughed in. You could see the wetted mixture shooting through a pipe in to the tun from upstairs. The place was a hive of whirring and trundling motors, and one of the few modern encroachments on the traditional brewery was that most of the moving parts were attached by a belt to a central motor that is now electric, but presumably was once steam powered.

Making our way upstairs we had a good gawk in to the empty boil kettle, which appeared to be steam driven, at least, it

Inside the copper

had some large copper coils at the bottom. Continuing in to the attic, we saw the coolship that would be put to use at the end of the brew day. The tour concluded in the barrel storage area, where 1, 2 and 3 year old lambic beer was aging. Some of the barrels were even oozing foam, which looked great.

We also had a good look at the barrel washing area, where the barrels were being steamed clean. One of them was attached to some big gyrating frame like the thing astronauts use to train for g-force or something.

We had a little taste of some of the beer, since it’s one of the few times that drinking at 7am is socially acceptable. I tried a blend called “cuvée Gilloises” or something to that effect, probably after the neighbouring district of Saint Gilles. It was lovely. We decided to return to our womenfolk who were sensibly snoring back at the apartment.
Later on in the day we returned, hoping to catch the final, crucial stage of the brew. After a very long boil, like any other beer, lambic beer needs to be cooled. Although most homebrewers use something like an immersion chiller where cold water is circulated through a copper coil that is immersed in the hot wort, and most commercial brewers use a plate chiller, where the beer is pumped through plates that have cold water pumped on the other side in the reverse direction, the traditional method of cooling beer is to use what is called a “coolship”. This is basicaly a very large surfaced shallow copper container, in Cantillon’s case it takes up the whole loft room. The hot wort is flooded in to the coolship, which spreads it over as much surface area as possible, and since copper conducts the heat away so well, the beer cools down gradually. One of the reasons that commercial breweries for the most part no longer use this method is that it involves leaving a large surface area of warm wort exposed for several hours, and during that time, before it is cool enough to pitch the yeast in to, it is ripe for infection by wild airborn yeasts.

Steaming Barrels

This is a boon for lambic brewers however, since they want those wild airborne yeasts, indigenous to the locality to innoculate the wort. At Cantillon, millions of colonies of these yeasts inhabit the very rafters of the brewery. They don’t steam clean the place, rather they let the friendly spiders take care of insects that might harm the beer, and there are some fairly impressive cobwebs in the place.

The room with the coolship was full of steam, and hard to see.

Watching the wort flood in to the coolship was almost a religious experience, indeed, you could view the mystical transformation that the wort undergoes the night after brewing, sitting in that Anderlect attic, as the brewing equivalent of the metaphysical transubstantiation of wine into the blood of the redeemer. Tastier end product though.

Awesome Cobweb

Having borne witness to the magic, we retired to the tasting area, to avail of our complimentary glass of unblened lambic, blended Gueuze, kriek, and my favourite, Rosé de Gambrinus, which is lambic beer blended with raspberries. We took a bottle of “Mamouche” back to the apartment, which, while nice, only confirmed my suspicion that I don’t really like elderflowers. Unfortunately they were out of “Fou’Foune”, which is lambic steeped with apricots. I still haven’t had a chance to try this. Cantillon open brew day is a great excuse to visit the bizarre and wonderful city of Brussels, to drink Lambic beer at 7am, and to see where the magic really happens. I feel this might become an annual pilgrimmage.


Filed under Beer, Brewery, equipment, Yeast