Slant starter lag time

If I make a starter from a slant, is the lag time after pitching to the fermenter a good indication of wether enough yeast was pitched?

There doesn't seem to be any hard data on how big of a starter to use when building from a slant. So if I build say, a 1.5L starter, pitch, and there is visable fermentation within 6 hours, can I assume the pitch rate was okay?

When I started using my yeast bank from slants I was not sure how to do this, I think you are asking the same question I did and that was how do I know if I have enough yeast. I could calculate the number of yeast cells required but with no idea of how many cells I had grown up in my flasks and I was not sure what to pitch. The process I came up with is to use the cell density as calculated from two sources. The first one was the maltose falcon web site and the second as using Mr Malty sort of backwards to show yeast cell density in a given volume of wort.

I have used this process now to make 8 batches of beer and all of them attenuated perfectly and very quickly.

Obviously you can use Mr Malty or the formula (OG-1)/48*(6-10)MYC*ml of wort to get the pitch rate, I prefer the formula over Mr Malty. To figure out how many yeast cells you have you can estimate this from knowing that yeast will keep multiplying so long as there is sufficient sugar/O2/nutrients. So the maltose falcon article on propagation and yeast maintenance gives you cell density for different types of starters ie basic, shaken, stir plate etc given 1.040 wort and a reasonable amount of nutrient. The numbers they had in table I then transferred to Mr Malty and with a bit of playing got similar results. It is a bit of a pain so I made a spread sheet using my numbers and it seems to work. The third way I check how much yeast I need to pitch is by letting it settle out and estimating the volume of slurry and using that as a basis for the number of cells you have created. The only other method I have seen as a guy who decants all the liquid off his yeast and weighs it. I have not tried this method yet.

I use a stir plate to make my yeast and I use my pressure cooker as an autoclave for anything I use in the yeast making process (anything that I can fit in it). Hence my slants are "canned" and I use a small baby food jar as the first step, then I use a large baby food jar, I then step to a 250ml flask with 150ml of wort in it and then a 1l flask with 700ml in it. All of that will fit in my pressure cooker so I can sterilize it before use.

As for lag time, I think lag time could be some type of indication however I would not trust this. I think is has more to do with how healthy the yeast is and how my O2 is in your wort. Hope my comments help, in the end the yeast I make from slants is far superior to anything I have used from a vial or smackpack,it seems they are healthy and very vigorous.

Good Luck

Clem

Appreciate the reply Clem.

Like a lot of things in brewing, it appears there is no (simple) definitive way to confirm I'm pitching the correct amount of yeast. I'll do a bit more reading and try come up with something that works for me. I like the idea of weighing the flask after decanting - much easier than trying to measure the volume of yeast. I think I'll start doing this, keep good notes and go from there.

The maltose falcons write up is very good. Looks like using a stir plate (which I am) is key.

Once you read what other people are doing and then reread the scientific articles you will gain in confidence once you have done it once or twice you will be thrilled and can't believe more people don't do it. The keys is getting confidence in your process and your equipment. I have my system lock down now and it takes me less time to make a starter than to drive to the LHBS to by yeast. Also I use wort from the dead space in my kettle and mash tun and can it in different size jars so it is ready to go.

This link here is the one where the guy weights his slurry and the table he uses. It is on the third page of this post, the original subject got lost along with a few other ones so you have to look for the bit you want.
https://www.homebrewtalk.com/f36/need-hefe-doctor-sour-tang-aftertaste-taste-multiple-hefes-264201/

Also if you don't have a pressure cooker (aka a poor mans autoclave) I highly recommend you get one. Saves your yeast having to compete with the nasties. My Stir plate, flasks and pressure cooker are the key to my yeast production.

Clem

Honey badger don'g give a fark.......look at that sleepy fook. You have to know how to multiply your yeast. I thought that if you make a 1L starter with a vial or smack pack, then make another 1L starter, you'd double your yeast twice, but it doesn't work that way. there's formulas for propagating yeast that should be followed if you want the proper cell count. for me, I usually just make a 2 or 3 liter starter, then pitch that into my wort, unless I'm making a 10 gallon batch, then I'll step it up and split my yeast into two fermenters. For homebrew purposes, I"m not sure if it's possible to over pitch, unless you have plenty of time and patience. I'd say just propagate the hell out of your slant, then pitch that biatch into your wort. for homebrewing purposes, I don't know that it's possible to overpitch a slant unless you're really determined to propogate the hell out of it. as far as actually SEEING signs of fermentation in a starter, you'll know if it's working, so if your starter is the right size, and you're seeing that starter get milkier, then you'll know the starter is doing the right thing. I never propogated from slants, so I'm probably not the person to listen to, but if you're building your starter to a certain size, then just build it and make sure it's working. (when you do starters, you just know when it's working)I'm not sure any of that makes sense, but to me it does...... hopefully it helps you

Clementine said:

It is a bit of a pain so I made a spread sheet using my numbers and it seems to work.
Clem

Click to expand...

Would you mind to share spreadsheet?

Does your numbers differs from maltose falcon"s table for same aeration method?

I used the maltose falcon pages as a basis, I then cross referenced Mr Malty and some tables from his book and got the same answer every time (or close enough Mr Malty pitch rate is 8.5MYC/ml of 1.048 wort) I will have to PM it to you as if I post it all the formula's don't work. Worst case I will post it on a web server at work and give you the address.

Clem

So I made a 1.5 litre starter a few days ago using 1272 from a slant. Put in the fridge for 24 hours or so then carefully decanted all the liquid.

Ended up with 88 grams of dense yeast (weighed emply flask before hand for reference). Pitched it to a 19 litre batch and was bubbling away within 3 hours.

I'm not quite sure what to make of this. I'm not even sure if this is comparable but it's quite alot more than Cidahmastah's chart (see clem's link above) would suggest.

I guess for now the best thing I can do is record my results and use it for future reference.

I guess this is a long shot but anyone have any idea how many cells would be in a gram?

Hope all that made sense.