For the next time you make it, a common way to take out the "bite" of raw garlic is to roast it first.
Chop off the top of the unpeeled head, drizzle in olive oil, sprinkle some salt, wrap in tin foil and pop in the oven.
More details and pictures covered here and here .
A quick search for roasted garlic pesto came up with a bunch of recipes as well.
I've used this trick with numerous recipes when I want lots of garlic, but want to take out the bite (from salsas, to guacamole, to just a straight garlic spread for bread).
cooking.stackexchange.com/users/231/talon8
I know this is a bit of an old question
but I came along it on my own search
so thought I'd share my solution.
I figured the problem with the excess garlic is that it's raw
so I sprinkled some parmesan on top of my pesto and baked it in the oven for 5-10mins.
Stirred through the now melted parmesen with the semi-cooked garlic and it tastes so much better.
Still a little garlic-y for my liking
but hey, we can't all be perfect.
Oh, I was making my pesto in a glass mixing bowl so just chucked the whole thing in the oven but make sure whatever you have it in is oven safe before whacking it in.
Enjoy!
cooking.stackexchange.com/users/14406/Betsy
I had this exact same problem when I first made homemade mojo...
It would snap your head back when it was fresh!
I had made it a day early for a party the next day and by the time the party came along, it was perfect!
Could you try this and let all the flavors marinate for a day or two before serving?
cooking.stackexchange.com/users/6791/Rikon
Pasteurization or freezing should cut the spiciness of garlic somewhat, since they reduce the flavor of whole cloves.
Pesto generally freezes well, so give that a shot first.
Heating the pesto briefly to a high temperature may affect the flavor, but will reduce garlic's role.
The shorter the period at heat is, the less it'll affect non-garlic flavors.
cooking.stackexchange.com/users/6345/BobMcGee
If you didn't pre-roast your garlic and need to fix it after the fact...
Throw your pesto in a saute pan with a little olive oil and cook it very lightly; that will help mellow the flavor.
Also, are you using lemon juice in your garlic?
I find that helps temper it while adding some much needed acid.
Finally, make sure you are cutting out the "sprout" piece from the center of each garlic clove as that usually has the strongest, most unpleasant flavor.
cooking.stackexchange.com/users/7232/Ann MacDonald
If you are willing to end up with something that is 'not pesto' but rather ' pesto cheese spread '
you can mix your pesto with cream cheese, butter, sour cream (etc..) to dilute the garlic over a larger volume.
The dairy product will help take the edge of the pesto and will give a delicious dish, just not the one you were planning.
cooking.stackexchange.com/users/6279/Cos Callis
The more the membranes in walls of raw garlic are bruised or torn, the spicier/stronger/more bitter it will taste.
Cutting fewer walls (instead of smashing which tears many of them) results in less spiciness especially when cut with an extremely sharp blade.
So if you're goint to use the garlic raw, chop or slice it rather than smashing if you don't want that extra pepperiness.
To get the skin off easily, a little bit of smashing with a knife blade won't affect things too much.
Cooking garlic makes it almost "sweet" though and removes that "hot" spicy taste, which is very different.
cooking.stackexchange.com/users/18033/JRazzo
Had the same problem and used a little dry mustard.
Seems to blens the garlic not the rest of the sauce.
cooking.stackexchange.com/users/27395/Donald
My hunch is that the answer is quite simple: mix your pasta into your pesto immediately after draining it, before it has time to cool.
This will cook the garlic just enough to take the zing out.
(Adding a bit of hot pasta water will help as well, as is often recommended in pesto recipes to thin the sauce out.)
cooking.stackexchange.com/users/822/Archagon
In Uganda some people don't like garlic at all
but we all know the importance of garlic and some foods are just tasteless without garlic.
So as a training chef I put a small pinch but for the times when I put a little too much of it, I use lime, oranges or lemon.
cooking.stackexchange.com/users/45586/Blsd Asimwe
I recently made some pesto from scratch and my end result, while delicious, was overpowered by a strong garlic flavor, and not entirely in a good way. I'm talking about that sharp, spicy flavor that garlic sometimes imparts.  I would have added more basil if I had it on hand, but I used all of my stash in the first go-round.  What else could I add to lessen the flavor?  Is there a general purpose ingredient for this situation?
How do I neutralize a strong garlic flavor?
cooking.stackexchange.com
<garlic><basil>
cooking.stackexchange.com/questions/17321
cooking.stackexchange.com/users/2826/rageear
Try roasting or sauteeing the garlic first to cook it, pasteurising or freezing it to cut the spiciness, or diluting it with cream cheese, butter, sour cream or mustard. You can marinate the flavours for a day or two before serving, or heat the pesto briefly (although this may affect the flavour of the pesto). Try roasting the garlic or heating the pesto slightly to take the edge off. You can also leave it to rest for a day before using.
Try roasting it before. Leave it to rest for a day before using. Freezing wil reduce the garlic strength. Heat the pesto very slightly. Try mixing mustard powder or cream cheese.